Fortis_Design_Brief_Appendix_B_06_28_21.pdf

FORTIS 8-AXLE SNF RAILCAR

DESIGN DOCUMENTATION

APPENDIX B – FINITE ELEMENT MODELING AND RESULTS

June 2021

Bi

DOE 8-Axle SNF Car – EEC Submittal – Appendix B

Table of Contents

List of Figures

List of Tables

1 Overview

1.1 Carbody Design

1.2 FE Analysis – General Procedure

1.3 FE Analysis Results Summary

2 FE Model and Mesh Quality

2.1 FE Model

2.2 Mesh Quality

3 Material Properties

3.1 Material Assignments

4 Static Strength Evaluation

4.1 Strength Evaluation by using von-Mises Stress

4.2 Arc Weld Evaluation

5 Static Strength Analysis

5.1 Summary

5.2 Vertical Load – 1.8g (LC01)

5.2.1 Applied Loads

5.2.2 Boundary Conditions

5.2.3 Reaction Forces

5.2.4 Deflected Shapes

5.2.5 von-Mises Stresses

5.2.6 Strength Analysis of Arc Welds

5.2.7 Summary

5.3 End Compression – Empty Car (LC02)

5.3.1 Applied Loads

5.3.2 Boundary Conditions

5.3.3 Reaction Forces

5.3.4 Deflected Shapes

5.3.5 von-Mises Stresses

5.3.6 Strength Analysis of Arc Welds

5.3.7 Summary

5.4 End Compression – Loaded Car (LC03)

5.4.1 Applied Loads

5.4.2 Boundary Conditions

5.4.3 Reaction Forces

5.4.4 Deflected Shapes

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5.4.5 von-Mises Stresses

5.4.6 Strength Analysis of Arc Welds

5.4.7 Summary

5.5 Combined Draft Load – Empty Car (LC04)

5.5.1 Applied Loads

5.5.2 Boundary Conditions

5.5.3 Reaction Forces

5.5.4 Deflected Shapes

5.5.5 von-Mises Stresses

5.5.6 Summary

5.6 Combined Draft Load – Loaded Car (LC05)

5.6.1 Applied Loads

5.6.2 Boundary Conditions

5.6.3 Reaction Forces

5.6.4 Deflected Shapes

5.6.5 von-Mises Stresses

5.6.6 Strength Analysis of Arc Welds

5.6.7 Summary

5.7 Combined Buff Load – Empty Car (LC06)

5.7.1 Applied Loads

5.7.2 Boundary Conditions

5.7.3 Reaction Forces

5.7.4 Deflected Shapes

5.7.5 von-Mises Stresses

5.7.6 Summary

5.8 Combined Buff Load – Loaded Car (LC07)

5.8.1 Applied Loads

5.8.2 Boundary Conditions

5.8.3 Reaction Forces

5.8.4 Deflected Shapes

5.8.5 von-Mises Stresses

5.8.6 Strength Analysis of Arc Welds

5.8.7 Summary

5.9 Impact Load – Loaded Car (LC08)

5.9.1 Applied Loads

5.9.2 Boundary Conditions

5.9.3 Reaction Forces

5.9.4 Deflected Shapes

5.9.5 von-Mises Stresses

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5.9.6 Strength Analysis of Arc Welds

5.9.7 Summary

5.10 Jacking Load – LC09

5.10.1 Applied Loads

5.10.2 Boundary Conditions

5.10.3 Reaction Forces

5.10.4 Deflected Shapes

5.10.5 von-Mises Stresses

5.10.6 Strength Analysis of Arc Welds

5.10.7 Summary

5.11 Lifting Load – LC10

5.11.1 Applied Loads

5.11.2 Boundary Conditions

5.11.3 Reaction Forces

5.11.4 Deflected Shapes

5.11.5 von-Mises Stresses

5.11.6 Strength Analysis of Arc Welds

5.11.7 Summary

5.12 Twist Load – LC11

5.12.1 Applied Loads

5.12.2 Boundary Conditions

5.12.3 Reaction Forces

5.12.4 Deflected Shapes

5.12.5 von-Mises Stresses

5.12.6 Strength Analysis of Arc Welds

5.12.7 Summary

5.13 Attachments Loads – LC12A/B/C/D/E/F/G

5.13.1 Applied Loads

5.13.2 Boundary Conditions

5.13.3 Reaction Forces

5.13.4 Deflected Shapes

5.13.5 von-Mises Stresses

5.13.6 Strength Analysis of Arc Welds

5.13.7 Summary

6 Fatigue Evaluation

6.1 Overview

6.2 Fatigue Evaluation Process

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List of Figures

Figure 1.1-1. Key Dimensions for the Car 11

Figure 1.1-2. Cask Car Model 12

Figure 1.2-1. General FE Procedure 14

Figure 2.1-1. Shell and Solid Elements used in the FE Model 16

Figure 2.1-2. Carbody FE Model 18

Figure 2.2-1. ANSYS Mesh Quality Check 19

Figure 3.1-1. Stress vs. Strain Curve 21

Figure 3.1-2. Carbody FE for Major Critical Members 23

Figure 4.1-1. von-Mises Stress Options in HyperView 24

Figure 5.2-1. Applied Loads for LC01 27

Figure 5.2-2. Boundary Conditions for LC01 28

Figure 5.2-3. Deflected Shapes for LC01 31

Figure 5.2-4. von-Mises Stress Plot of the Carbody for LC01 34

Figure 5.2-5. von-Mises Stress Plot on Center Sill for LC01 35

Figure 5.2-6. von-Mises Stress Plot on Side Sill for LC01 35

Figure 5.2-7. von-Mises Stress Plot on Body Bolster for LC01 36

Figure 5.2-8. von-Mises Stress Plot on Transverse Members for LC01 36

Figure 5.2-9. Nodes with High Stress Concentrations for LC01 37

Figure 5.2-10. Weld #1 High Stress Concentration for LC01 38

Figure 5.2-11. Weld #2 High Stress Concentration for LC01 39

Figure 5.2-12. Weld #3 High Stress Concentration for LC01 40

Figure 5.2-13. Weld #4 High Stress Concentration for LC01 41

Figure 5.2-14. Weld #5 High Stress Concentration for LC01 42

Figure 5.2-15. Weld #6 High Stress Concentration for LC01 43

Figure 5.3-1. Applied Loads for LC02 45

Figure 5.3-2. Boundary Conditions for LC02 46

Figure 5.3-3. Deflected Shapes for LC02 49

Figure 5.3-4. von-Mises Stress Plot of Whole Carbody for LC02 51

Figure 5.3-5. von-Mises Stress Plot on Center Sill for LC02 52

Figure 5.3-6. von-Mises Stress Plot on Side Sill for LC02 52

Figure 5.3-7. von-Mises Stress Plot on Body Bolster for LC02 53

Figure 5.3-8. von-Mises Stress Plot on Transverse Members for LC02 53

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Figure 5.3-9. Nodes with High Stress Concentrations for LC02 54

Figure 5.3-10. Weld #1 High Stress Concentration for LC02 55

Figure 5.4-1. Applied Loads for LC03 57

Figure 5.4-2. Boundary Conditions for LC03 58

Figure 5.4-3. Deflected Shapes for LC03 61

Figure 5.4-4. von-Mises Stress Plot of Whole Carbody for LC03 64

Figure 5.4-5. von-Mises Stress Plot on Center Sill for LC03 65

Figure 5.4-6. von-Mises Stress Plot on Side Sill for LC03 65

Figure 5.4-7. von-Mises Stress Plot on Body Bolster for LC03 66

Figure 5.4-8. von-Mises Stress Plot on Transverse Members for LC03 66

Figure 5.4-9. Nodes with High Stress Concentrations for LC03 67

Figure 5.4-10. Weld #1 High Stress Concentration for LC03 68

Figure 5.4-11. Weld #2 High Stress Concentration for LC03 69

Figure 5.4-12. Weld #3 High Stress Concentration for LC03 70

Figure 5.4-13. Weld #4 High Stress Concentration for LC03 71

Figure 5.5-1. Applied Loads for LC04 73

Figure 5.5-2. Boundary Conditions for LC04 74

Figure 5.5-3. Deflected Shapes for LC04 77

Figure 5.5-4. von-Mises Stress Plot of Whole Carbody for LC04 79

Figure 5.5-5. von-Mises Stress Plot on Center Sill for LC04 80

Figure 5.5-6. von-Mises Stress Plot on Side Sill for LC04 80

Figure 5.5-7. von-Mises Stress Plot on Body Bolster for LC04 81

Figure 5.5-8. von-Mises Stress Plot on Transverse Members for LC04 81

Figure 5.6-1. Applied Loads for LC05 83

Figure 5.6-2. Boundary Conditions for LC05 84

Figure 5.6-3. Deflected Shapes for LC05 87

Figure 5.6-4. von-Mises Stress Plot of the Carbody for LC05 90

Figure 5.6-5. von-Mises Stress Plot on Center Sill for LC05 91

Figure 5.6-6. von-Mises Stress Plot on Side Sill for LC05 91

Figure 5.6-7. von-Mises Stress Plot on Body Bolster for LC05 92

Figure 5.6-8. von-Mises Stress Plot on Transverse Members for LC05 92

Figure 5.6-9. Nodes with High Stress Concentrations for LC05 93

Figure 5.6-10. Weld #1 High Stress Concentration for LC05 94

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Figure 5.6-11. Weld #2 High Stress Concentration for LC05 95

Figure 5.6-12. Weld #3 High Stress Concentration for LC05 96

Figure 5.6-13. Weld #4 High Stress Concentration for LC05 97

Figure 5.6-14. Weld #5 High Stress Concentration for LC05 98

Figure 5.7-1. Applied Loads for LC06 100

Figure 5.7-2. Boundary Conditions for LC06 101

Figure 5.7-3. Deflected Shapes for LC06 104

Figure 5.7-4. von-Mises Stress Plot of the Carbody for LC06 106

Figure 5.7-5. von-Mises Stress Plot on Center Sill Structures for LC06 107

Figure 5.7-6. von-Mises Stress Plot on Side Sill for LC06 107

Figure 5.7-7. von-Mises Stress Plot on Body Bolster for LC06 108

Figure 5.7-8. von-Mises Stress Plot on Transverse Members for LC06 108

Figure 5.8-1. Applied Loads for LC07 110

Figure 5.8-2. Boundary Conditions for LC07 111

Figure 5.8-3. Deflected Shapes for LC07 114

Figure 5.8-4. von-Mises Stress Plot of Whole Carbody for LC07 117

Figure 5.8-5. von-Mises Stress Plot on Center Sill for LC07 118

Figure 5.8-6. von-Mises Stress Plot on Side Sill for LC07 118

Figure 5.8-7. von-Mises Stress Plot on Body Bolster for LC07 119

Figure 5.8-8. von-Mises Stress Plot on Transverse Members for LC07 119

Figure 5.8-9. Nodes with high stress concentrations for LC07 120

Figure 5.8-10. Weld #1 High Stress Concentration for LC07 121

Figure 5.8-11. Weld #2 High Stress Concentration for LC07 122

Figure 5.8-12. Weld #3 High Stress Concentration for LC07 123

Figure 5.8-13. Weld #4 High Stress Concentration for LC07 124

Figure 5.8-14. Weld #5 High Stress Concentration for LC07 125

Figure 5.9-1. Applied Loads for LC08 127

Figure 5.9-2. Boundary Conditions for LC08 128

Figure 5.9-3. Deflected Shapes for LC08 131

Figure 5.9-4. von-Mises Stress Plot of the Carbody for LC08 133

Figure 5.9-5. von-Mises Stress Plot on Center Sill for LC08 134

Figure 5.9-6. von-Mises Stress Plot on Side Sill for LC08 134

Figure 5.9-7. von-Mises Stress Plot on Body Bolster for LC08 135

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Figure 5.9-8. von-Mises Stress Plot on Transverse Members for LC08 135

Figure 5.9-9. Nodes with High Stress Concentrations for LC08 136

Figure 5.9-10. Weld #1 High Stress Concentration for LC08 137

Figure 5.9-11. Weld #3 High Stress Concentration for LC08 138

Figure 5.9-12. Weld #3 High Stress Concentration for LC08 139

Figure 5.9-13. Weld #4 High Stress Concentration for LC08 140

Figure 5.9-14. Weld #5 High Stress Concentration for LC08 141

Figure 5.10-1. Applied Loads for LC09 143

Figure 5.10-2. Boundary Conditions for LC09 144

Figure 5.10-3. Deflected Shapes for LC09 147

Figure 5.10-4. von-Mises Stress Plot of the Carbody for LC09 150

Figure 5.10-5. von-Mises Stress Plot on Center Sill for LC09 151

Figure 5.10-6. von-Mises Stress Plot on Side Sill for LC09 151

Figure 5.10-7. von-Mises Stress Plot on Body Bolster for LC09 152

Figure 5.10-8. von-Mises Stress Plot on Transverse Members for LC09 152

Figure 5.10-9. Nodes with High Stress Concentrations for LC09 153

Figure 5.10-10. Weld #1 High Stress Concentration for LC09 154

Figure 5.10-11. Weld #2 High Stress Concentration for LC09 155

Figure 5.10-12. Weld #3 High Stress Concentration for LC09 156

Figure 5.11-1. Applied Loads for LC10 158

Figure 5.11-2. Boundary Conditions for LC10/10A/10B 159

Figure 5.11-3. Deflected Shapes (Scale Factor = 15) for LC10/10A/10B 163

Figure 5.11-4. von-Mises Stress Plot of the Carbody for LC10/10A/10B 166

Figure 5.11-5. Nodes with High Stress Concentrations for LC10B 167

Figure 5.11-6. Weld #1 High Stress Concentration for LC10B 168

Figure 5.11-7. Weld #2 High Stress Concentration for LC10B 169

Figure 5.12-1. Evaluation of Side-Bearing Deflection from Wheel Lift 171

Figure 5.12-2. Applied Loads for LC11 171

Figure 5.12-3. Boundary Conditions for LC11 172

Figure 5.12-4. Deflected Shapes for LC11 175

Figure 5.12-5. von-Mises Stress Plot of the Carbody for LC11 178

Figure 5.12-6. von-Mises Stress Plot on Center Sill for LC11 179

Figure 5.12-7. von-Mises Stress Plot on Side Sill for LC11 179

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Figure 5.12-8. von-Mises Stress Plot on Body Bolster for LC11 180

Figure 5.12-9. von-Mises Stress Plot on Transverse Members for LC11 180

Figure 5.12-10. Nodes with High Stress Concentrations for LC11 181

Figure 5.12-11. Weld #1 High Stress Concentration for LC11 182

Figure 5.12-12. Weld #2 High Stress Concentration for LC11 183

Figure 5.12-13. Weld #3 High Stress Concentration for LC11 184

Figure 5.13-1. Applied Loads for LC12A/B/C/D/E/F/G 188

Figure 5.13-2. Boundary Conditions for LC12A/B/C/D 189

Figure 5.13-3. Boundary Conditions for LC12E/F 190

Figure 5.13-4. Boundary Conditions for LC12G 191

Figure 5.13-5. Deflected Shapes (Scale Factor = 1.0) for LC12A/B/C/D/E/F/G 196

Figure 5.13-6. von-Mises Stress Plot at the Cask Brackets for LC12A/B 198

Figure 5.13-7. von-Mises Stress Plot at the Cask Brackets for LC12C/12D 199

Figure 5.13-8. von-Mises Stress Plot at the Cask Brackets for LC12E/12F 200

Figure 5.13-9. von-Mises Stress Plot at the Cask Brackets for LC12G 201

Figure 5.13-10. Weld #1 for LC12A/B/C/D 202

Figure 5.13-11. Weld #2 for LC12G 203

Figure 5.13-12. Weld #3 for LC12E/F 204

Figure 6.2-1. von-Mises Stress Contours for Fatigue Evaluation 206

Figure 6.2-2. Location 1 - Center Sill Flange - Transition 209

Figure 6.2-3. Location 2 - Side Sill Flange - Upper Transition 209

Figure 6.2-4. Location 3 - Side sill flange - Lower Transition 210

Figure 6.2-5. Location 4 - Center sill Web and Top Cover Plate Joint 210

Figure 6.2-6. Location 5 - Side sill web and Top Cover Plate Joint 211

Figure 6.2-7. Location 6 - Center sill to Transverse Gusset Weld Corner 211

Figure 6.2-8. Location 7 - Center Sill Web to Vertical Stiffener (Vertical Weld) 212

Figure 6.2-9. Location 8 - Center Sill Web to Transverse Stiffener (Weld Corner) 212

Figure B2-10. Weld #1 High Stress Concentration for LC01 220

Figure B2-11. Nodal Forces Extracted from FE Model 222

Figure B2-12. Weld Stress Calculation and Margin of Safety for Weld #1 224

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List of Tables

Table 1.1-1. Estimated Weight for SNF Car 13

Table 3.1-1. Material Summary for the FE Model 20

Table 3.1-2. Multi-linear Kinematic Model 20

Table 5.1-1. Summary of static FE Analysis 26

Table 5.2-1. Reaction Force Summary (lb.) for LC01 29

Table 5.2-2. von-Mises Stress Summary for LC01 32

Table 5.3-1. Reaction Force Summary (lb.) for LC02 47

Table 5.3-2. von-Mises Stress Summary 49

Table 5.4-1. Reaction Force Summary (lb.) for LC03 59

Table 5.4-2. von-Mises Stress Summary for LC03 62

Table 5.5-1. Reaction Force Summary (lb.) for LC04 75

Table 5.5-2. von-Mises Stress Summary for LC04 77

Table 5.6-1. Reaction Force Summary (lb.) for LC05 85

Table 5.6-2. von-Mises Stress Summary for LC05 88

Table 5.7-1. Reaction Force Summary (lb.) for LC06 102

Table 5.7-2. von-Mises Stress Summary for LC06 104

Table 5.8-1. Reaction Force Summary (lb.) for LC07 112

Table 5.8-2. von-Mises Stress Summary for LC07 115

Table 5.9-1. Reaction Force Summary (lb.) for LC08 129

Table 5.9-2. von-Mises Stress Summary for LC08 131

Table 5.10-1. Reaction Force Summary (lb.) for LC09 145

Table 5.10-2. von-Mises Stress Summary for LC09 148

Table 5.11-1. Reaction Force Summary (lb.) for LC10 160

Table 5.11-2. Reaction Force Summary (lb.) for LC10A 160

Table 5.11-3. Reaction Force Summary (lb.) for LC10B 160

Table 5.11-4. von-Mises Stress Summary for LC10/10A/10B 163

Table 5.12-1. Reaction Force Summary (lb.) for LC11 173

Table 5.12-2. von-Mises Stress Summary for LC11 176

Table 5.13-1. Attachment load cases for LC12A/B/C/D/E/F/G 186

Table 5.13-2. von-Mises Stress Summary for LC12A/B/C/D/E/G 197

Table 6.2-1. Fatigue Results Summary 208

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1 Overview

Based on the design goals and requirements laid out by the U.S. Department of Energy (DOE), Sharma & Associates, Inc. (SA) developed three concepts for an 8-axle railcar capable of transporting Spent Nuclear Fuel (SNF) and High-Level radioactive waste (HLW) casks in Phase

1 of the project. In Phase 2, the chosen concept (Concept 1) was developed further into a detailed design. This concept uses two span bolsters and four 125-Ton Swing Motion trucks from Amsted Rail. The span bolster is a standard Amsted design that was previously approved by the Association of American Railroads (AAR), and hence, is not discussed further here.

This document reports on the structural analysis of the carbody that was conducted to confirm that the structural performance of the design meets the criteria laid out in section

S-2043 of the AAR standards. This document, which is an appendix of the Preliminary Design submittal, Structural Analysis Section, was prepared in accordance with the requirements of

Paragraph 4.7 of the AAR Standard S-2043, and presents static and fatigue results of carbody finite element (FE) analysis.

1.1 Carbody Design

The carbody was designed to carry all seventeen (17) required cask configurations and incorporates a mounting system that is identical to the system outlined in the Atlas project.

The carbody uses a primary center sill that is a box-section, flanked by two (2) side sills that approximate I-sections, and is strengthened in the transverse direction through two bolsters, end sills, and multiple transverse beams. An overview of the design is presented in Appendix

A of the main report and the images below highlight the key layout.

The carbody will be made from structural steel conforming to ASTM A572, Grade 65 - a relatively easily available material. It will be fabricated by welding together steel plates that have been cut to shape.

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Figure 1.1-1. Key Dimensions for the Car

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Figure 1.1-2. Cask Car Model

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The loads and weights used for the structural analysis are primarily based on the heaviest SNF cask, the HISTAR 190XL cask, with combined cask and cradle weight of 435,000 lb. The weight of the end stops of 44,000 lb. is also for the HISTAR 190SL cask. The resulting axle load is approximately 78,125 lb. The estimated weight for cask car is shown in the table below. Specific loads used for each load case are derived from these and are outlined in Table

5.1-1.

Table 1.1-1. Estimated Weight for SNF Car

BUDGET (lb.) Estimate (lb.)

LADING WEIGHT 479,000 479,000

4 X 125 TON SWING MOTION TRUCKS 48,000 48,000

2 X SPAN BOLSTERS

22,000 20,000

CAR STRUCTURE 74,000 72,250

SECONDARY ELEMENTS 5,000 4,000

WELD AND PAINT 2,000 1,750

LIGHT WEIGHT 151,000 146,000

GROSS WEIGHT 630,000 625,000

AXLE LOAD 78,750 78,125

1.2 FE Analysis – General Procedure

In general, the finite element model was derived from an appropriate CAD model by discretizing the design through the use of a commercial FE meshing software (HyperMesh).

The FE mesh thus created was analyzed using a commercial FE analysis software (ANSYS) for the required set of load cases. An overview of the analysis procedure is shown below, and additional detail is provided in subsequent sections.

The analysis matrix included the following load cases: End Compression, Combined Draft and Buff, Impact Load, Diagonal Jacking, Vertical, Lifting, Twist, and Attachment Loads.

In addition to the static analysis, fatigue analysis of key locations was conducted as per the guidelines and procedures laid out in AAR MSRP, Section C-II, Chapter 7.

The analysis process and results for both the static and the fatigue analyses are outlined in subsequent sections of this appendix.

Amsted Rail Span Bolster Drawing Reference: CZ14687. Estimated weight for the span bolster is only 7,840 lb.

from the drawing. An estimated weight of 2160 lb. was added to account for coupler pocket attachment and coupler for a total of 10,000 lb. for each span bolster.

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Figure 1.2-1. General FE Procedure

1.3 FE Analysis Results Summary

Several rounds of FE analyses were performed to review the stress levels on the car structural model. Feedback from these FE analyses was used to revise car design details as required. All critical areas of high stress have been revised and addressed. This document presents the final design state of the carbody as reflected by several key load cases. Overall, the current design meets the structural adequacy requirements that have been laid out in the AAR Standard

S-2043. In general, the design presented is reasonably conservative; high stresses observed are generally very local, and artifacts of the modeling process; these are explained further in the individual load case sections.

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2 FE Model and Mesh Quality

2.1 FE Model

The FE model of the carbody was meshed from the geometry model using HyperMesh. Figure

2.1-1 and Figure 2.1-2 present the FE model of the carbody.

Shell elements best represent parts that are relatively thin compared to their overall surface area and typically have a uniform thickness. FE solvers assume the shell element to lie at the middle of the thickness. The mesh created on the surfaces will lie at the mid-surface of the part.

The Mid-surface in HyperMesh panel allows the mid-surface representation of a solid part to be extracted. It can be used to generate a finite element shell representation of a solid geometry.

The original geometry that is selected to extract the mid-surface from remains unchanged.

The new geometry representing the mid-surface is placed in a new component collector called Middle Surface, or in the current component, depending on choices made during creation.

The mesh was created based on the mid-surface geometry and is primarily defined by shell elements (Shell181) for all sheets and plate structures, with few hexahedral elements for the central plate (solid component) and brick elements (Solid 185) for the cask brackets, lugs, shear block and end-stops brackets as shown in the figure below. In addition, mass elements and rigid elements (CERIG and RBE3) were used at the locations where constraints and loads are defined. ANSYS normally uses 3 integration points through the material thickness, and automatically increases the number of integration points to 5 when plastic material is detected.

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(a) Shell elements (Shell 181) used in the FE Model

(b) Solid elements (Solid185) used in the FE Model

Figure 2.1-1. Shell and Solid Elements used in the FE Model

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(a) FE Model - ISO view

b) End-Stop brackets close view

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(c) Cask brackets close view

(d) Underframe close view

Figure 2.1-2. Carbody FE Model

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2.2 Mesh Quality

To achieve reliable results and to reduce the margin of error, it is necessary to create a good quality mesh, especially for critical areas (high stress locations). There are a several quality parameters which account for the ideal shape of an element, some critical ones are: Jacobian

(>0.4) and Aspect Ratio (＜5). Both ANSYS and HyperMesh define limiting criteria for these parameters; the SA model creation process ensured that the mesh created met these limiting criteria in order to assure a high-quality mesh. A quality check from the ANSYS FE model is presented in Figure 2.2-1. The Jacobian and the aspect ratio have zero errors. In addition to that, the model was reviewed for free edges and nodes.

Figure 2.2-1. ANSYS Mesh Quality Check

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3 Material Properties

3.1 Material Assignments

The carbody structure will be fabricated using carbon steel material type, ASTM A572-Grade

65. Table 3.1-1 lists corresponding mechanical properties for this material type. For the analysis, a multi-linear kinematic hardening material model with 5 data points (Table 3.1-2) was used. The stress vs. strain curve was derived based on the method outlined in Appendix

C of the AAR manual (AAR MSRP, M-1001, Section C – Part II, “Design, Fabrication, and

Construction of Freight Cars”), see Figure 3.1-1.

Major critical components for carbody structure are shown in Figure 3.1-2. In the results section for each of the load cases, the lowest margin of safety is shown for each of these major components.

Table 3.1-1. Material Summary for the FE Model

Property ASTM A572 - Grade 65

Young’s Modulus (ksi) 29,000

Yield Strength (ksi) 65

Tensile Strength (ksi) 80

Elongation (%) 17

Poisson Ratio 0.30

Density (lb./in

) 0.274

Table 3.1-2. Multi-linear Kinematic Model

Total Strain Stress, ksi

0 0

0.002138 61.998

0.004241 65.000

0.020180 72.000

0.169997 80.000

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Figure 3.1-1. Stress vs. Strain Curve

(a) Center Sill (Critical Component #1)

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(b) Side Sills (Critical component #2)

(c) Body Bolster (Critical component #3)

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(d) Transverse members (Critical component #4)

Figure 3.1-2. Carbody FE for Major Critical Members

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4 Static Strength Evaluation

4.1 Strength Evaluation by using von-Mises Stress

The von-Mises stresses were examined on main structural members and connections in the carbody. The deformation shapes and stress patterns around high stress zones were checked further to understand the observed stress responses.

Post-processing for static load cases was conducted within the framework of HyperView.

Figure 4.1-1 shows three options for the von-Mises stress displayed in HyperView. The “Max” option in the “Layers” reports the maximum von-Mises stresses along the shell thickness. The

“Use Corner Data” option displays color bands by interpolating available corner results within each element. “Advanced Averaging” means that tensor results were transformed into the global system and then each component was averaged separately to obtain an average tensor.

The von-Mises stresses were calculated from this averaged tensor. These options are applied to all the von-Mises stress results in this report.

Figure 4.1-1. von-Mises Stress Options in HyperView

Compared to car structural design efforts conducted using classical methods, finite element analyses tend to highlight locations with local stresses; while some of these high stress locations are valid representations of the load path issues, stress concentrations, or stiffness variations

, several others are artifacts of modeling such as load application, or reaction locations, sharp transitions, abrupt changes in thickness or stiffness, etc.

Short of modeling every small transition and radius, every weld and weld transition, and other details, analysis results will have some localized high stress areas; these were evaluated using engineering judgment, an understanding of member and joint criticality, load paths, expected deformation behavior, etc.

Throughout the design optimization process, several locations highlighted by the analysis were redesigned to improve structural performance. For example, locations of higher stress highlighted during the November review have been addressed in this revised design.

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4.2 Arc Weld Evaluation

All the critical joints on the DOE SNF car are full strength welds. These critical joints are located on the main load transfer paths within the carbody. Full strength welds imply that the weld is not weaker than the base metal. Thus, for all full strength weld joints, structural weld adequacy was confirmed by checking the von-Mises stresses on their connecting plates against the allowable stress values during the FE post-processing.

As confirmation, key welds were additionally analyzed considering non-CJP weld types, as presented later in this document. The analysis process was based on identifying welds for all the critical load cased that were over a nominal stress value of 50% of the material allowable

65 ksi (ASTM A572, Grade 65), which highlights locations with stressed welds

. At these key locations, the forces expected at the welds were extracted from the FE results, and the minimum weld sizing needed to meet the requirements was identified. While the design intent at these critical locations is to use full strength welds, this process helps review potential weld stress issues, and also offers weld design flexibility, if needed at specific locations. As shown later in this document, based on the minimum weld sizes needed at these critical locations, full-strength or complete joint penetration (CJP) welds should provide well over the needed minimum weld capacities. In the final implementation, based upon the requirements of the fabrication shop, partial strength welds may be used in the carbody design when the full strength joint designs are either unnecessary or impractical based on a case-by-case review with the design team.

Weld capacities were evaluated by extracting forces and moments in the vicinity of the weld from the FE results and evaluating the weld sizes needed to resist the forces and moments using classical weld analysis techniques. Weld allowable stresses and techniques used followed the American Welding Society (AWS) Standard 15.1. These weld calculations were done using spreadsheets, and sample spreadsheets can be shared with reviewers upon request.

If a high stress location is symmetric with respect to the centerline of the car, then only the location with the highest von-Mises stress was evaluated.

Appendix B2 presents a detailed example of these calculations, describing the method used for the arc welds evaluation.

The value of 0.5 has been chosen based on the AAR requirements.

B26

5 Static Strength Analysis

5.1 Summary

This section highlights the results from critical load cases on the underframe as required by AAR S-2043. In general, parent material stresses and weld capacities in both the main members and at key connections are within allowable limits.

Table 5.1-1. Summary of static FE Analysis

Load Cases Force Application Allowable Stress Remarks

LC

Descriptions S-2043

01 Vertical Load 4.1.5.2 1.8(DL+LL)

Yield or 80% of ultimate Meets requirements

02 End Compression – Empty Car 4.1.5.7 1.0(DL Vert.) + 1,000,000 lb. end compression Yield or 80% of ultimate Meets requirements

03 End Compression – Loaded Car 4.1.5.7 1.0(DL+LL) + 1,000,000 lb. end compression Yield or 80% of ultimate Meets requirements

04 Combined Draft Load – Empty Car 4.1.5.6 1.8(DL) Vert+1.5(LAT) +1.8(350,000 lb.) Draft Yield or 80% of ultimate Meets requirements

Combined Draft Load – Loaded

Car 4.1.5.6

1.8(DL+LL) Vert+1.5(LAT) +1.8(350,000 lb.)

Draft Yield or 80% of ultimate Meets requirements

06 Combined Buff Load – Empty Car 4.1.5.6 1.8(DL) Vert+1.5(LAT) +1.8(350,000 lb.) Buff Yield or 80% of ultimate Meets requirements

07 Combined Buff Load – Loaded Car 4.1.5.6 1.8(DL+LL) Vert+1.5(LAT) +1.8(350,000 lb.)

Buff Yield or 80% of ultimate Meets requirements

08 Impact Load – Loaded Car 4.1.5.8 1.0(DL+LL)Vert+1,250,000 lb. Ultimate Meets requirements

09 Jacking Load 4.1.5.4 1.0(DL+LL)+40%GRL on one jacking pad +

10%GRL on other pad Yield or 80% of ultimate Meets requirements

10 Lifting Load S-234 Apply load to generate 40% of GRL on one of the lifting lugs

Yield at the connection zone Meets requirements;

11 Twist Load 4.1.5.5 3” of displacement on one side of one truck 56% of Yield Meets requirements;

12 Attachment loads

AAR

Rule 88

Longitudinal 7.5g, Lateral 2g and Vertical 2g Ultimate Meets requirements

DL: Dead Load, LL: Live Load, LAT: Lateral Load

B27

5.2 Vertical Load – 1.8g (LC01)

5.2.1 Applied Loads

For this load case the load was distributed on the carbody as shown in Figure 5.2-1. With a gravity load of 1.8*386.4 in/s

, the weight of the carbody is 73,102 lb. A vertical load of

195,750 lb. was applied to each of the cask’s brackets. In addition, a vertical load of 9,900 lb.

was applied to each of the eight end-stop brackets.

Note: Appendix B1 has additional information regarding load application.

Figure 5.2-1. Applied Loads for LC01

B28

5.2.2 Boundary Conditions

Figure 5.2-2 shows the boundary conditions used in this load case. The center plates at the carbody bolster had vertical and lateral constraints. In addition, at one end, the centerplate was constrained in longitudinal direction and was not allowed to rotate about X-axis.

Figure 5.2-2. Boundary Conditions for LC01

B29

5.2.3 Reaction Forces

Table 5.2-1 lists the reaction forces (RFs) in this load case. The reaction force in the vertical direction is matching closely the load applied on the carbody. (195,750 lb.*4) + (9,900 lb.*8)

+ 73,102 lb. (FE carbody mass)*1.8= 993,783 lb.

Table 5.2-1. Reaction Force Summary (lb.) for LC01

Constrained

Nodes

B.C.

RFs in direction X

RFs in direction

Y

RFs in direction

Z

775522 T

YZ

= 0 - 496,843 0.0

775521 T XYZ, ROTx

= 0 0.0 496,940 0.0

Total 0.0 993,783 0.0

Below is a screenshot of the reaction forces extracted from ANSYS.

The 21,134 lbf·in moment about X axis was caused by a minor asymmetry in the mesh from left to right and is the result of a very small offset of 0.04in in lateral direction, which is considered acceptable for this load case.

B30

5.2.4 Deflected Shapes

Figure 5.2-3 plots the deformed shape of whole carbody in X, Y and Z directions. Review of these plots shows the deflections are as expected for this load case.

(a) Deflected Shapes in direction X (Scale Factor = 1.0)

(b) Deflected Shapes in direction Y (Scale Factor = 1.0)

B31

(c) Deflected Shapes in direction Y (Scale Factor = 15)

(d) Deflected Shapes in direction Z (Scale Factor = 1.0)

Figure 5.2-3. Deflected Shapes for LC01

B32

5.2.5 von-Mises Stresses

Figure 5.2-4 plots the von-Mises stress in the whole carbody. The allowable for this load case is 80% of the material ultimate strength, 64ksi. Table 5.2-2 summarizes the peak von-Mises stress in the carbody structure. The maximum von-Mises stress, 45.3 ksi, is located at the center sill. The carbody strength is considered adequate for this load case.

Table 5.2-2. von-Mises Stress Summary for LC01

Stressed Zone

Peak Stress (ksi) Yield Stress (ksi)

(0.8*F u ) Utilization

Ratio Remarks

Node IDs Nodal

Value Material Value

Figure 5.2-5 2228405 (Center Sill) 45.3 ASTM A572 64 71% Okay

Figure 5.2-6 4270316 (Side Sill) 35.9 ASTM A572 64 57% Okay

Figure 5.2-7 5590007 (Body Bolster) 32.9 ASTM A572 64 51% Okay

Figure 5.2-8 4835285 (Transverse members)

41.2 ASTM A572 64 64% Okay

B33

(a) Top View of von-Mises Stress Plot of the Carbody

B34

(b) Bottom View of von-Mises Stress Plot of the Carbody

Figure 5.2-4. von-Mises Stress Plot of the Carbody for LC01

B35

Figure 5.2-5. von-Mises Stress Plot on Center Sill for LC01

Figure 5.2-6. von-Mises Stress Plot on Side Sill for LC01

B36

Figure 5.2-7. von-Mises Stress Plot on Body Bolster for LC01

Figure 5.2-8. von-Mises Stress Plot on Transverse Members for LC01

B37

5.2.6 Strength Analysis of Arc Welds

von-Mises stresses higher than 65ksi*0.5=32.5 ksi are highlighted in Figure 5.2-9 below. The majority of the arc welds are complete joint penetration (CJP), however, the calculations provided below identify the minimum weld sizes needed. Six types of arc welds (the ones with the highest von-Mises stress) are presented for further evaluation.

As outlined earlier, the intent of this weld evaluation is to identify key locations and the minimum weld sizes needed at these locations, as a conservative exercise. The current design intent is to use full-strength CJP welds at these critical locations. The margin of safety =

(Allowable Stress/Actual Stress)-1 is given for each of the interest arc welds.

Figure 5.2-9. Nodes with High Stress Concentrations for LC01

B38

5.2.6.1 Weld #1

Weld #1 is at the side sill, Figure 5.2-10. This arc weld was evaluated as a partial joint penetration (PJP) groove weld of 0.5625in size with a fillet weld of a 0.5in size. The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

(a) von-Mises

(b) Solid Model

Figure 5.2-10. Weld #1 High Stress Concentration for LC01

The minimum margin of safety for this weld is 0.84 and the average margin of safety is 1.54, therefore the strength of this weld is considered adequate (See Appendix B2 for calculations).

B39

5.2.6.2 Weld #2

The weld location is on the center sill, Figure 5.2-11. This was evaluated as a double fillet weld of 0.5625in. The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

(a) von Mises

Figure 5.2-11. Weld #2 High Stress Concentration for LC01

The minimum margin of safety for this weld is 0.67 and the average margin of safety is 0.79, therefore the strength of this weld is considered adequate.

B40

5.2.6.3 Weld #3

Weld # 3 is at the center sill connection to the top plate, Figure 5.2-12. This was evaluated as a

PJP groove weld of 0.5625in size with a fillet weld of 0.5in size. The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

Figure 5.2-12. Weld #3 High Stress Concentration for LC01

The minimum margin of safety for this weld is 0.58, and the average margin of safety is 2.68, B41

5.2.6.4 Weld #4

The weld location is at the side sill connection to the top plate, Figure 5.2-13. This has been evaluated as a PJP groove weld of 0.5625in size with a fillet weld of 0.5in size. The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

Figure 5.2-13. Weld #4 High Stress Concentration for LC01

The minimum margin of safety for this weld is 2.84, therefore the strength of this weld is considered adequate.

B42

5.2.6.5 Weld #5

The weld location is at the center sill connection to the bottom plate, Figure 5.2-14. This was evaluated as a double fillet weld of 0.5625in size. The allowable stress in the weld is 0.3*

Ultimate Stress (80ksi) = 24ksi.

Figure 5.2-14. Weld #5 High Stress Concentration for LC01

The minimum margin of safety for this weld is 0.42, and the average margin of safety is 0.63, B43

5.2.6.6 Weld #6

The weld location is at the center sill connection to the bolster plate, Figure 5.2-15. This has been evaluated as a PJP groove weld of 0.5625in size with a fillet weld of 0.5in size. The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

Figure 5.2-15. Weld #6 High Stress Concentration for LC01

The minimum margin of safety for this weld is 0.66, and the average margin of safety is 1.08, B44

5.2.7 Summary

For this load case, the von-Mises stress was checked for the entire carbody. The maximum stress is 45.3 ksi, which is local and lower than the allowable material stress.

Generally, the stresses are much lower than the allowable, 64 ksi, including at key locations such as the bottom flange in the center of the car and at the transition zones. Six arc welds were identified as needing further checks. All of them meet the strength requirements.

A review of the rest of the nodes showed the stresses are considered adequate for this load case.

B45

5.3 End Compression – Empty Car (LC02)

For this load case, the car structure was designed to sustain a compressive load of

1,000,000 lb. applied at the center plate at each end of the car on the nominal centerline of couplers.

5.3.1 Applied Loads

Figure 5.3-1 shows the FE model used for the analysis and how the 1,000,000 lb. longitudinal load was applied. The car was empty for this load case, and the gravity was 386.4 in/s

. The weight of the FE carbody was 73,102 lb.

Figure 5.3-1. Applied Loads for LC02

386.4 in/s

Longitudinal load

B46

5.3.2 Boundary Conditions

Figure 5.3-2 shows the boundary conditions used in this load case. The centerplate of carbody bolster had vertical and lateral constraints on each side of the car. The longitudinal constraint was applied at the center plate, as shown in the figure below.

Figure 5.3-2. Boundary Conditions for LC02

B47

5.3.3 Reaction Forces

Table 5.3-1 lists the reaction forces (RFs) in this load case. The reaction forces in the vertical and longitudinal directions are matching closely to the applied load. The weight of the carbody is 73,102 lb.

Table 5.3-1. Reaction Force Summary (lb.) for LC02

Constrained Nodes B.C.

RFs in direction

X

RFs in direction

Y

RFs in direction

Z

775521 T

YZ

= 0 - 36,561 -0.640

775522 T YZ_RotX

= 0 - 36,542 0.641

855728 T X = 0 1,000,000 - -

Total 1,000,000 73,102 0.0

B48

5.3.4 Deflected Shapes

Figure 5.3-3 plots the deformed shape of whole carbody shell in X, Y and Z directions.

Review of these plots shows the deflections are as expected for this load case.

(b) Deflected Shapes in direction Y (Scale Factor = 25)

B49

(c) Deflected Shapes in direction Z (Scale Factor = 1.0)

Figure 5.3-3. Deflected Shapes for LC02

5.3.5 von-Mises Stresses

Figure 5.3-4 plots the von-Mises stress in the whole carbody shell. Table 5.3-2 summarizes the peak von-Mises stress in the carbody structure. The highest stress, 57.3 ksi is on the center plate, at the point of load application, and is lower than allowable for the material. All the other stresses are fairly low and well within the limits; the structural performance of major components and connections are good for the current design. The carbody strength is considered adequate for this load case.

Table 5.3-2. von-Mises Stress Summary

Stressed

Zone

Yield Stress (ksi)

(0.8F u ) Utilizatio n Ratio Remarks

Node IDs Nodal

Value

Material Value

Figure 5.3-5 2377648 (Center Sill) 38.4 ASTM A572 64 60% Okay

Figure 5.3-6 5535887 (Side Sill) 28.4 ASTM A572 64 44% Okay

Figure 5.3-7 5612048 (Body Bolster) 57.3 ASTM A572 64 89% Okay

Figure 5.3-8 4820978 (Transverse members)

26.1 ASTM A572 64 41% Okay

B50

(a) Top View of von-Mises Stress Plot of the Whole Carbody

B51

(b) Bottom View of von-Mises Stress Plot of Whole Carbody

Figure 5.3-4. von-Mises Stress Plot of Whole Carbody for LC02

B52

Figure 5.3-5. von-Mises Stress Plot on Center Sill for LC02

Figure 5.3-6. von-Mises Stress Plot on Side Sill for LC02

B53

Figure 5.3-7. von-Mises Stress Plot on Body Bolster for LC02

Figure 5.3-8. von-Mises Stress Plot on Transverse Members for LC02

B54

5.3.6 Strength Analysis of Arc Welds

von-Mises stresses higher than 65ksi*0.5=32.5 ksi are highlighted in the figure below. As noted earlier, the majority of the arc welds are CJP, however, the calculations provided below identify the minimum weld sizes needed. One type of arc weld (the one with the highest von-Mises stress) is presented for further evaluation.

Figure 5.3-9. Nodes with High Stress Concentrations for LC02

5.3.6.1 Weld #1

Weld #1 is at the center plate connection to the center sill, Figure 5.3-10. This arc weld is evaluated as a PJP groove weld of 2.438in size with a fillet weld of a 1.375in size. Weld allowable is 0.3* Ultimate Stress (80ksi) = 24ksi.

B55

Figure 5.3-10. Weld #1 High Stress Concentration for LC02

The minimum margin of safety for this weld is 0.31 and the average margin of safety is 0.71

B56

5.3.7 Summary

For this load case, von-Mises stress was checked for the entire carbody. The highest nodal stress is 57.3 ksi at the center plate. This is very local and lower than the material allowable of

64 ksi. One arc weld was identified as needing further check. This weld meets the strength requirements.

All the other stresses are fairly low and well within the limits; the structural performance of major components and connections are good for current design.

Overall, the current design is adequate for this load case.

B57

5.4 End Compression – Loaded Car (LC03)

The carbody structure was designed to resist a load of 1,000,000 lb. applied longitudinally to the center plate in combination with vertical loads without exceeding 80% of ultimate strength of any member.

5.4.1 Applied Loads

Figure 5.4-1 plots the loads applied in this load case. The longitudinal load of 1,000,000 lb.

was applied at the centerplate, as shown in Figure 5.4-2 . The vertical loads were applied at the casks and end-stops brackets as shown in the figure below.

Figure 5.4-1. Applied Loads for LC03

B58

5.4.2 Boundary Conditions

Figure 5.4-2 shows the boundary conditions used in this load case. The centerplate of carbody bolster has vertical and lateral constraints on each side of the car. The longitudinal constraint was applied at the center plate, as shown in the figure below.

Figure 5.4-2. Boundary Conditions for LC03

B59

5.4.3 Reaction Forces

Table 5.4-1 lists the reaction forces (RFs) in this load case. The reaction forces in the vertical and longitudinal directions match closely to the applied forces, (73,102 lb.+108,750 lb.*4+5,500 lb.*8=552,102 lb.).

Table 5.4-1. Reaction Force Summary (lb.) for LC03

Constrained Nodes B.C.

RFs in direction X

RFs in direction Y

RFs in direction Z

775521 T

YZ

= 0 - 276,080 -0.622

775522 T YZ_RotX

= 0 - 276,020 0.641

784220 T X = 0 1,000,000 - -

Total 1,000,000 552,100 -0.0

B60

5.4.4 Deflected Shapes

Figure 5.4-3 plots the deformed shape of whole carbody shell in directions X, Y and Z.

(b) Deflected Shapes in direction Y (Scale Factor = 25.0)

B61

Figure 5.4-3. Deflected Shapes for LC03

B62

5.4.5 von-Mises Stresses

Figure 5.4-4 plots the von-Mises stress of whole carbody. Table 5.4-2 summarizes the peak von-Mises stress in the carbody structure. The highest nodal stress of 61.2 ksi, is at the center plate connection to the bolster plate. The stress is very local and lower than the allowable for the material. Overall, the carbody strength is considered adequate for this load case.

Table 5.4-2. von-Mises Stress Summary for LC03

Allowable Stress (ksi)

(0.8F u ) Utilization

Ratio Remarks

Node IDs Nodal Value Material Value

Figure 5.4-5

2379114

Center Sill

35.9 ASTM A572 64 56% Okay

Figure 5.4-6 5535887

Side Sill

28.1 ASTM A572 64 44% Okay

Figure 5.4-7

5611539

Body

Bolster

61.2 ASTM A572 64 96% Okay

Figure 5.4-8

2555207

Transverse

Members

16.3 ASTM A572 64 25% Okay

B63

B64

(b) Bottom View of von-Mises Stress Plot of Carbody

Figure 5.4-4. von-Mises Stress Plot of Whole Carbody for LC03

B65

Figure 5.4-5. von-Mises Stress Plot on Center Sill for LC03

Figure 5.4-6. von-Mises Stress Plot on Side Sill for LC03

B66

Figure 5.4-7. von-Mises Stress Plot on Body Bolster for LC03

Figure 5.4-8. von-Mises Stress Plot on Transverse Members for LC03

B67

5.4.6 Strength Analysis of Arc Welds

von-Mises stresses higher than 65ksi*0.5=32.5 ksi are highlighted in the figure below. The calculations provided below identify the minimum weld sizes needed. Four types of arc welds

(the ones with the highest von-Mises stress) are presented for further evaluation.

As outlined earlier, the intent of this weld evaluation is to identify key locations and the minimum weld sizes needed at these locations, as a conservative exercise. The current design intent is to use full-strength CJP welds at these critical locations.

Figure 5.4-9.Nodes with High Stress Concentrations for LC03

B68

5.4.6.1 Weld #1

The first weld location is at the bolster, Figure 5.4-10. This arc weld was evaluated as a double fillet weld of 0.5625 in size. Weld allowable is 0.3* Ultimate Stress (80ksi) = 24ksi.

(b) FE Model

Figure 5.4-10. Weld #1 High Stress Concentration for LC03

The minimum margin of safety for this weld is 0.47, the average margin of safety is 1.28, and therefore, the strength of this weld is considered adequate, even with a PJP application.

Margin of safety = (Allowable Stress/Actual Stress)-1

B69

5.4.6.2 Weld #2

The location for the second highest stress concentration is at the bolster, Figure 5.4-11. This was evaluated as a groove weld of 0.375in (both sides) size with fillet weld of 0.375in size.

The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

Figure 5.4-11. Weld #2 High Stress Concentration for LC03

The minimum margin of safety for this weld is 0.74 and therefore its strength is considered adequate even with a PJP application.

B70

5.4.6.3 Weld #3

This location is also at the bolster, Figure 5.4-12. This was evaluated as a double-sided PJP groove weld of 0.375in with fillet weld of 0.75in. The allowable stress in the weld is 0.3*

Ultimate Stress (80ksi)*1.5 = 36ksi. It is higher because the load axis is perpendicular to the weld axis and AWS allows an additional factor of 1.5.

Figure 5.4-12. Weld #3 High Stress Concentration for LC03

The minimum margin of safety for this weld is 1.11 and therefore its strength is considered adequate.

B71

5.4.6.4 Weld #4

Weld #4 is at the center plate connection to the center sill, Figure 5.6-10. This arc weld was evaluated as a PJP groove weld of 2.438 in size with a fillet weld of a 1.375 in size. The allowable stress in the weld is 0.3* Ultimate Stress (80ksi) = 24ksi.

Figure 5.4-13. Weld #4 High Stress Concentration for LC03

The minimum margin of safety for this weld is 0.18, and, the average margin of safety is 0.57;

therefore, the strength of this weld is considered adequate.

B72

5.4.7 Summary

For the current design, no nodes have von-Mises stresses in excess of the allowable stress. The maximum von-Mises stress is 61.2 ksi at the center plate connection to the bolster plate, and is very local.

All the other stresses are within the limits; the structural performance of major components and connections are good for the current design. A review of the connecting welds shows that the arc welds have the capacity needed.

Overall, the gross stress levels are low, and the current design is adequate for this load case.

B73

5.5 Combined Draft Load – Empty Car (LC04)

The carbody structure was designed to resist a combined load of 1.8g applied in vertical direction, 0.45g applied in lateral direction and 630,000 lb. of draft applied in longitudinal direction, without exceeding 80% of ultimate strength of any member.

5.5.1 Applied Loads

Figure 5.5-1 plots the loads applied in this load case. The longitudinal loads of 630,000 lb.

were applied at the centerplate. The car was empty for this load case and the gravity was

695.52 in/s in vertical direction and 173.88in/s in lateral direction. The weight of the car was 73,102 lb.

Figure 5.5-1. Applied Loads for LC04

695.52 in/s

173.88 in/s

B74

5.5.2 Boundary Conditions

Figure 5.5-2 shows the boundary conditions used in this load case. The centerplate of carbody bolster had vertical and lateral constraints on each side of the car. The longitudinal constraint was applied at the center plate, as shown in the figure below.

Constraints on the side bearings used nonlinear springs to simulate interaction between the truck and carbody side bearings.

Characteristics of these two nonlinear springs are shown below and are consistent with truck suspension characteristics.

Figure 5.5-2. Boundary Conditions for LC04

B75

5.5.3 Reaction Forces

Table 5.5-1 lists the reaction forces (RFs) in this load case. The reaction force in the vertical direction is matching closely the applied load, 73,102 lb.*1.8= 131,583 lb. Also, in the lateral direction, the applied load 73,102 lb.*0.45=32,895 lb. is matching the reaction force.

Table 5.5-1. Reaction Force Summary (lb.) for LC04

Constrained Nodes B.C.

RFs in direction X

RFs in direction Y

RFs in direction Z

775521 T

YZ

= 0 - 57,317 16,453

775522 T

YZ

= 0 - 57,306 16,443

784220 T X = 0 -630,000 -

784452 T

XYZ

= 0 0.0 8,469.2 0.0

784453 T

XYZ

= 0 0.0 8,492.3 0.0

Total -630,000 131,583 32,896

B76

5.5.4 Deflected Shapes

Figure 5.5-3 plots the deformed shape of whole carbody shell in directions X, Y and Z.

(b) Deflected Shapes in direction Y (Scale Factor = 25.0)

B77

Figure 5.5-3. Deflected Shapes for LC04

5.5.5 von-Mises Stresses

Figure 5.5-4 plots the von-Mises stress of whole carbody. Table 5.5-2 summarizes the peak von-Mises stress in the carbody for the main components. The maximum von-Mises stress is at the center plate, 37.4 ksi. This is local and is due to the proximity of the load application point. All the stresses are lower than the maximum stress allowable of 64 ksi. The carbody strength is considered adequate for this load case.

Table 5.5-2. von-Mises Stress Summary for LC04

(0.8F u

Utilization

Ratio Remarks

Node IDs Nodal Value Material Value

Figure 5.5-5 2379114

Center Sill

21.5 ASTM A572 64 34% Okay

Figure 5.5-6 5535887

Side Sill

17.7 ASTM A572 64 28% Okay

Figure 5.5-7 781066

Body Bolster

37.4 ASTM A572 64 58% Okay

Figure 5.5-8

4820841

Transverse

19.5 ASTM A572 64 30% Okay

B78

B79

Figure 5.5-4. von-Mises Stress Plot of Whole Carbody for LC04

B80

Figure 5.5-5. von-Mises Stress Plot on Center Sill for LC04

Figure 5.5-6. von-Mises Stress Plot on Side Sill for LC04

B81

Figure 5.5-7. von-Mises Stress Plot on Body Bolster for LC04

Figure 5.5-8. von-Mises Stress Plot on Transverse Members for LC04

B82

5.5.6 Summary

von-Mises stresses for the whole carbody were checked. The highest nodal stress (37.4 ksi) is at the center plate. This is local and is at the load application point. All the other stresses are lower than maximum allowable of 64ksi.

At all key areas, von-Mises stresses for the empty case are much lower than the corresponding loaded case. Since weld evaluation was done for loaded car (Section 5.6) and all are passing the strength requirements, the strength of the…