T9070-AJ-DPC-120_3010 SHOCK DESIGN CRITERIA FOR SURFACE SHIPS.pdf

T9070-AJ-DPC-120/3010

NAVSEA DESIGN PRACTICES AND CRITERIA MANUAL

SHOCK DESIGN CRITERIA

FOR

SURFACE SHIPS

THIS MANUAL SUPERSEDES 0908-LP-000-3010 REV. 1 DATED 30 SEPTEMBER 1995.

DISTRIBUTION STATEMENT A: APPROVED FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED.

PUBLISHED BY DIRECTION OF COMMANDER, NAVAL SEA SYSTEMS COMMAND

28 SEPTEMBER 2017

A

LIST OF EFFECTIVE PAGES

Dispose of superseded pages in accordance with applicable regulations.

Dates of issue for original and subsequent revisions:

Original (0908-LP-000-3010)………………….... 31 May 1976

0908-LP-000-3010 Revision 1……………......... 30 September 1995

T9070-AJ-DPC-120/3010……………................. 28 September 2017

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 178, CONSISTING OF THE FOLLOWING:

Page No.

Title and A i through ix/(x blank)

1-1/(1-2 blank)

2-1 through 2-2

3-1 through 3-37/(3-38 blank)

4-1 through 4-17/(4-18 blank)

5-1 through 5-4

6-1 through 6-9/(6-10 blank)

7-1 through 7-6

A-1 through A-9/(A-10 blank)

B-1 through B-3/(B-4 blank)

C-1 through C-2

D-1 through D-4

E-1 through E-31/(E-32 blank)

F-1 through F-9/(F-10 blank)

G-1 through G-11/(G-12 blank)

H-1 through H-7/(H-8 blank)

TMDER

i

TABLE OF CONTENTS

Chapter/Paragraph/Title Page

Foreword .................................................................................................................................................................................... ix Chapter 1 Introduction ...................................................................................................................................................................... 1-1

1.1 Purpose. .............................................................................................................................................................................. 1-1 Chapter 2 Applicable Documents ..................................................................................................................................................... 2-1

2.1 Introduction. ....................................................................................................................................................................... 2-1

2.1.1 Government Publications. ........................................................................................................................................ 2-1

2.2 Order of Precedence. .......................................................................................................................................................... 2-2 Chapter 3 Dynamic Design Analysis Method ................................................................................................................................... 3-1

3.1 Introduction. ....................................................................................................................................................................... 3-1

3.1.1 Shock Hardening Design Process Figures. ............................................................................................................... 3-1

3.1.2 Five-Phase Approach. ............................................................................................................................................... 3-1

3.1.3 Limitations of the DDAM. ....................................................................................................................................... 3-2

3.1.4 Limitations of the Structure Being Modeled. ........................................................................................................... 3-2

3.1.4.1 Assessing Structural Elements of Equipment. ................................................................................................ 3-5

3.1.4.2 Limitations in Evaluating Various Hazards. ................................................................................................... 3-6

3.2 Problem Formulation Phase. ............................................................................................................................................... 3-6

3.2.1 Shock Grades. ........................................................................................................................................................... 3-6

3.2.2 Mounting Locations. ................................................................................................................................................. 3-7

3.2.2.1 Mounting Definitions. .................................................................................................................................... 3-7

3.2.2.2 Item Mounted to Two Different Parts of the Ship. ......................................................................................... 3-8

3.2.2.3 Evaluating Specific Characteristics of Deck Structure. .................................................................................. 3-8

3.2.2.4 Items Not Mounted Directly on Deck or Basic Hull Structure. ...................................................................... 3-8

3.2.2.4.1 Shock Design Values for Items Mounted on Structural Bulkheads. ............................................................ 3-8

3.2.2.4.2 Criteria for Lightweight Items Mounted on Machinery Space Upper Levels. ............................................ 3-8

3.2.3 Shock Design Values. ............................................................................................................................................... 3-8

3.2.3.1 Elastic Shock Design Values. ......................................................................................................................... 3-8

3.2.3.2 Elastic-Plastic Shock Design Values. ............................................................................................................. 3-9

3.2.3.3 Special Criteria for Displacement-Critical Items............................................................................................ 3-9

3.2.3.4 Special Criteria for Hold-Down/Locating Devices. ....................................................................................... 3-9

3.2.3.5 Minimum Acceleration Value. ....................................................................................................................... 3-9

3.2.4 Critical Areas. ........................................................................................................................................................... 3-9

3.3 Mathematical Modeling Phase............................................................................................................................................ 3-9

3.3.1 Major Steps. .............................................................................................................................................................. 3-9

3.3.2 Basic Modeling Assumptions. ................................................................................................................................ 3-10

3.3.3 Frequency Calculations. ......................................................................................................................................... 3-10

3.3.4 Mass Lumping. ....................................................................................................................................................... 3-10

3.3.5 Mass Locations. ...................................................................................................................................................... 3-12

3.3.6 Designation of Structural Model. ........................................................................................................................... 3-12

3.3.7 Special Modeling Criteria. ...................................................................................................................................... 3-12

3.4 Coefficient Computation Phase. ....................................................................................................................................... 3-12 ii

Chapter/Paragraph/Title Page

3.4.1 Mass Matrices. ........................................................................................................................................................ 3-13

3.5 Dynamic Computation Phase. ........................................................................................................................................... 3-13

3.5.1 Modal Analysis. ...................................................................................................................................................... 3-13

3.5.2 Dynamic Reduction Techniques. ............................................................................................................................ 3-14

3.5.2.1 Verification of Adequacy. ............................................................................................................................ 3-14

3.5.2.2 Reducing Number of Dynamic Degrees of Freedom. .................................................................................. 3-15

3.5.2.3 Guidance for the Number of Master Degrees of Freedom. ........................................................................... 3-15

3.6 Evaluation Phase. .............................................................................................................................................................. 3-16

3.6.1 Modal Assessment. ................................................................................................................................................. 3-16

3.6.1.1 Closely Spaced Modes. ................................................................................................................................. 3-16

3.6.1.2 Treatment of Closely Spaced Modes. ........................................................................................................... 3-16

3.6.2 Shock Design Values to Apply. .............................................................................................................................. 3-17

3.6.2.1 Derivation. .................................................................................................................................................... 3-18

3.6.2.2 Multi-Directional Response Analysis. .......................................................................................................... 3-18

3.6.2.3 Special Design Criteria. ................................................................................................................................ 3-18

3.6.3 Number of Modes to Use. ....................................................................................................................................... 3-18

3.6.3.1 Set Cut-Off Frequency. ................................................................................................................................. 3-18

3.6.3.2 Sort Modes by Modal Effective Weight. ...................................................................................................... 3-18

3.6.3.3 Modal Effective Weight in Excess of Minimum Percent of Total Weight. .................................................. 3-19

3.6.3.4 Modal Effective Weights Less than Minimum Percent of Total Weight. ..................................................... 3-19

3.6.4 Calculating Stresses Within Each Mode. ................................................................................................................ 3-20

3.6.5 Summing of Stresses and Deflections Across the Modes by NRL Method. ........................................................... 3-21

3.6.6 Combining Operating and Shock Stresses (Total Stresses). ................................................................................... 3-22

3.6.7 Response Assessment. ............................................................................................................................................ 3-23

3.6.7.1 Closely Spaced Modes (CSM) Method. ....................................................................................................... 3-24

3.6.7.1.1 Analysis Methods. ..................................................................................................................................... 3-26

3.6.7.1.1.1 Modal Amplitude Correction. ................................................................................................................. 3-26

3.6.7.1.1.2 Closed Form Treatment. ......................................................................................................................... 3-26

3.6.7.1.1.3 Numerical Treatment. ............................................................................................................................. 3-27

3.6.7.1.1.4 Graphical Treatment. .............................................................................................................................. 3-28

3.6.7.1.2 Example Problems. .................................................................................................................................... 3-28

3.6.7.1.2.1 Approach 1: Closed Form Treatment (Example Problem). ................................................................... 3-29

3.6.7.1.2.2 Approach 2: Numerical Treatment (Example Problem). ....................................................................... 3-30

3.6.7.1.2.3 Approach 3: Graphical Treatment (Example Problem). ....................................................................... 3-31

3.6.7.2 The Algebraic Summation Method (ASM). ................................................................................................. 3-32

3.6.7.2.1 Example ASM. .......................................................................................................................................... 3-32

3.6.7.2.2 Examining ASM Results. .......................................................................................................................... 3-35

Chapter 4 Foundation Shock Design ................................................................................................................................................ 4-1

4.1 Introduction. ........................................................................................................................................................................ 4-1

4.2 Method 1 (Design Method for Hold Down Means). ........................................................................................................... 4-1

4.3 Method 2 (SDOF DDAM Method). .................................................................................................................................... 4-2

4.4 Extent of Foundation. ......................................................................................................................................................... 4-3 iii

Chapter/Paragraph/Title Page

4.4.1 Equipment Mounted on Shell Framing. .................................................................................................................... 4-3

4.4.2 Equipment Mounted on Upper Levels of Machinery Spaces. .................................................................................. 4-3

4.4.3 Equipment Mounted on Decks. ................................................................................................................................ 4-3

4.4.4 Equipment Mounted on Structural Bulkheads. ......................................................................................................... 4-3

4.4.5 Equipment Supported by Stanchions. ....................................................................................................................... 4-4

4.4.6 Equipment Supported by Pallets. .............................................................................................................................. 4-4

4.4.7 Equipment Mounted on Nonstructural Bulkheads. ................................................................................................... 4-4

4.4.8 Mechanical Attachments for Non-Metallic Hulls. .................................................................................................... 4-4

4.5 Requirements for Supporting Ship Structure. ..................................................................................................................... 4-4

4.6 Dynamic Analysis of a Foundation – Single Degree of Freedom System. ......................................................................... 4-4

4.6.1 Example – Single Degree of Freedom System. ........................................................................................................ 4-6

4.6.1.1 Characteristics. ............................................................................................................................................... 4-6

4.6.1.2 Procedural Steps. ............................................................................................................................................ 4-6

4.7 Example – Uni-Directional Response Analysis of a Foundation – Multi-Mass System. ................................................. 4-10

4.7.1 Characteristics. ....................................................................................................................................................... 4-10

4.7.2 Procedural Steps. .................................................................................................................................................... 4-10

4.8 Dynamic Analysis of a Foundation – Multi-Directional Response Analysis. .................................................................. 4-11

4.8.1 Modal Analysis for Multi-Direction Response. ...................................................................................................... 4-12

4.8.2 Shock Input in One Selected Direction. ................................................................................................................. 4-12

4.8.3 Example – Multi-Directional Response Analysis. .................................................................................................. 4-13

4.9 Finite Element Application of DDAM. ............................................................................................................................ 4-16 Chapter 5 DDAM of Grade B Items ................................................................................................................................................. 5-1

5.1 Introduction. ....................................................................................................................................................................... 5-1

5.2 Example Procedures for Dynamic Analysis of Grade B Items. .......................................................................................... 5-1

5.2.1 Example 1. ................................................................................................................................................................ 5-1

5.2.2 Example 2. ................................................................................................................................................................ 5-4

Chapter 6 Allowable Stress Criteria ................................................................................................................................................. 6-1

6.1 General Criteria. ................................................................................................................................................................. 6-1

6.1.1 General Stress. .......................................................................................................................................................... 6-1

6.1.2 Local Stress. ............................................................................................................................................................. 6-1

6.1.3 General Membrane Stress. ........................................................................................................................................ 6-1

6.1.4 General Membrane Plus Bending Stress. ................................................................................................................. 6-1

6.1.5 Local Membrane Stress. ........................................................................................................................................... 6-1

6.1.6 Local Membrane Plus Bending Stress. ..................................................................................................................... 6-2

6.1.7 Adjacent Local Stresses Regions. ............................................................................................................................. 6-2

6.1.8 Stress Evaluation and Classification. ........................................................................................................................ 6-2

6.1.8.1 Stress Evaluation Procedure for Solid Elements. .................................................................................................. 6-4

6.1.8.2 Stress Evaluation Procedure for Thin Plate/Shell Elements. ................................................................................. 6-4

6.1.8.3 Stress Evaluation Procedure for Beam Elements. .................................................................................................. 6-5

6.2 Allowable Design Stresses for Grade A and Grade B Items Designed to Suit Elastic Shock Design Values. ................... 6-5

6.2.1 CASE 1. .................................................................................................................................................................... 6-5

6.2.2 CASE 2. .................................................................................................................................................................... 6-5 iv

Chapter/Paragraph/Title Page

6.2.3 CASE 1 and CASE 2. ............................................................................................................................................... 6-6

6.2.4 Special Design Criteria. ............................................................................................................................................ 6-6

6.3 Allowable Design Stresses for Grade A Items Designed to Suit Elastic-Plastic Shock Design Values. ............................ 6-6

6.3.1 Limiting Permanent Deflection. ............................................................................................................................... 6-6

6.3.2 Where Considerable Plastic Bending Can be Tolerated. .......................................................................................... 6-6

6.3.3 Areas of Foundations or Equipment in Way of Hold-Down Bolts. .......................................................................... 6-6

6.3.4 Column Buckling and Bearing Stresses. ................................................................................................................... 6-7

6.4 Allowable Design Stresses for Grade B Items Designed to Suit Elastic-Plastic Shock Design Values. ............................. 6-7

6.5 Allowable Bolt Stresses. ..................................................................................................................................................... 6-7

6.6 Allowable Stresses for Wire Rope. ..................................................................................................................................... 6-7

6.7 Allowable Stress for Non-Metallic Material. ...................................................................................................................... 6-7

6.8 Special Stress Criteria for Foundations. .............................................................................................................................. 6-7

6.9 Special Criteria for Piping Connections. ............................................................................................................................. 6-7

6.10 Ductility. ........................................................................................................................................................................... 6-7

6.11 Special Criteria for Design of Hold-Down Bolts. ............................................................................................................. 6-8

6.12 Wetted Surface Dynamic Analysis. .................................................................................................................................. 6-8

6.12.1 Phase I. ................................................................................................................................................................... 6-8

6.12.2 Phase II. .................................................................................................................................................................. 6-8

6.13 Special Criteria for Use of Mechanical Adjustable Chocks (MAC). ................................................................................ 6-8

6.13.1 Allowable Stresses for the MAC Body and Associated Structure. ......................................................................... 6-9

6.13.2 Allowable Stress for Hold-Down Bolts in Mechanical Adjustable Chocks (MAC). .............................................. 6-9

Chapter 7 Dynamic Shock Analysis Review and Approval Procedures ........................................................................................... 7-1

7.1 Background. ........................................................................................................................................................................ 7-1

7.2 Report Format and Content. ................................................................................................................................................ 7-1

7.2.1 Mathematical Model Report Format and Content. ................................................................................................... 7-1

7.2.2 Dynamic Analysis Report Format and Content. ....................................................................................................... 7-3

7.3 Review and Approval Authority. ........................................................................................................................................ 7-4

7.3.1 Equipment, Weapons, and Systems Analyses. ......................................................................................................... 7-4

7.3.2 Foundation Analyses. ............................................................................................................................................... 7-4

7.3.3 Ten Sample Foundations. ......................................................................................................................................... 7-4

7.4 Navy Review and Approval/Disapproval Cycle. ................................................................................................................ 7-5

7.5 Guidelines and Requirements. ............................................................................................................................................ 7-5

Appendix A Sample Computation of Normal Modes of a Structure ............................................................................................... A-1 A.1 Introduction. ...................................................................................................................................................................... A-1

Appendix B Finite Element Method for DDAM Analysis............................................................................................................... B-1 B.1 Introduction. ...................................................................................................................................................................... B-1

Appendix C Transient Analysis Methods ........................................................................................................................................ C-1 C.1 Introduction. ...................................................................................................................................................................... C-1 C.2 Transient Analysis Method. .............................................................................................................................................. C-1 C.3 Two Levels of Transient Response Calculations. ............................................................................................................. C-1 C.4 Transient Analysis (Transient Shock Analysis) Process. .................................................................................................. C-2

Appendix D Oblique Directional Shock Inputs ............................................................................................................................... D-1 v

Chapter/Paragraph/Title Page

D.1 Introduction....................................................................................................................................................................... D-1 D.2 Oblique Equipment Orientation. ....................................................................................................................................... D-1 D.3 Oblique Equipment Orientation – Illustrative Example. ................................................................................................... D-1

Appendix E Sample Finite Element DDAM Analysis – Format and Content .................................................................................. E-1 E.1 Introduction. ....................................................................................................................................................................... E-1 E.2 Mathematical Model. ......................................................................................................................................................... E-2 E.3 Computer Analysis. ............................................................................................................................................................ E-2 E.4 Results. ............................................................................................................................................................................... E-2 E.5 Sketch or Arrangement of Item. ......................................................................................................................................... E-4 E.6 Sketch of Equipment. ......................................................................................................................................................... E-5 E.7 Sketches of Foundation. ..................................................................................................................................................... E-7 E.8 Mathematical Model Sketch (Node Numbers). ................................................................................................................ E-14 E.9 Mathematical Model Sketch (Element Numbers). ........................................................................................................... E-15 E.10 Mathematical Model Sketch (Mass Locations). ............................................................................................................. E-16 E.11 Computer Input. ............................................................................................................................................................. E-17 E.12 DDAM Output. .............................................................................................................................................................. E-21

E.12.1 Frequency, Participation Factors, and Modal Weights for Each Mode Used in the NRL Sum. .......................... E-21 E.12.2 Modal Mass vs. Frequency and Eigenvector vs. Node Number Charts. .............................................................. E-22 E.12.3 Modal Output (Forces). ........................................................................................................................................ E-25 E.12.4 Modal Output (Stresses). ...................................................................................................................................... E-28

Appendix F Example Application of the Allowable Stress Criteria ................................................................................................. F-1 F.1 Introduction. ....................................................................................................................................................................... F-1

Appendix G Bolt and Bolt Joint Design .......................................................................................................................................... G-1 G.1 Introduction....................................................................................................................................................................... G-1 G.2 Applying an External Force to a Bolted Joint. .................................................................................................................. G-2 G.3 Joint Diagrams. ................................................................................................................................................................. G-4 G.4 Joint Diagrams with External Forces Applied. ................................................................................................................. G-6

Appendix H List of Abbreviations, Acronyms, Symbols, and Definitions ...................................................................................... H-1 H.1 Introduction....................................................................................................................................................................... H-1 H.2 List of Abbreviations, Acronyms, and Symbols. .............................................................................................................. H-1 H.3 List of Definitions. ............................................................................................................................................................ H-5 vi

LIST OF ILLUSTRATIONS

Figure No. and Title Page

Figure 3-1. Shock Qualification Process – Overview. ..................................................................................................................... 3-3 Figure 3-2. Equipment Shock Qualification by the Multi-DOF DDAM (see Chapter 3). ............................................................... 3-4 Figure 3-3. Foundation Shock Design by SDOF DDAM (see Chapters 4 and 5). ........................................................................... 3-5 Figure 3-4. Mounting Locations for Surface Ships. ......................................................................................................................... 3-7 Figure 3-5. Simply Supported Shaft. ............................................................................................................................................. 3-11 Figure 3-6. Schematic Representation of Simply Supported Shaft. ............................................................................................... 3-11 Figure 3-7. Mode Selection Process. ............................................................................................................................................. 3-20 Figure 3-8. Combined Responses of Two Undamped, Closely Spaced Modes. ............................................................................ 3-25 Figure 3-9. Combined Response of Two Damped (2 Percent), Closely Spaced Modes. ............................................................... 3-25 Figure 3-10. Envelope/Sum of components for use with Closely Spaced Modes Sum. ................................................................ 3-28 Figure 3-11. Bending and Shear Forces on Beam Element. .......................................................................................................... 3-34 Figure 4-1. Schematic Representation of a Single Degree of Freedom System. .............................................................................. 4-5 Figure 4-2. Single Degree of Freedom Foundation Model. ............................................................................................................. 4-6 Figure 4-3. Schematic Representation of a Single Degree of Freedom System. .............................................................................. 4-7 Figure 4-4. Schematic Representation of a Simply Supported Beam Loaded at the Center. ........................................................... 4-9 Figure 4-5. Schematic Representation of a Mathematical Model for an MDR Analysis. .............................................................. 4-13 Figure 4-6. Force Schematic for an MDR Analysis. ...................................................................................................................... 4-16 Figure 4-7. Schematic Representation of a Multi-Mass Finite Element Foundation Mathematical Model. .................................. 4-17 Figure 5-1. Single Degree of Freedom Foundation Model for Dynamic Analysis of Grade B Item. .............................................. 5-1 Figure 5-2. Schematic Representation of a Single Degree of Freedom Foundation. ....................................................................... 5-2 Figure 5-3. Equipment/Foundation Configuration with a Cantilevered Motor. ............................................................................... 5-4 Figure 5-4. Schematic Representation of a Two Degree of Freedom System. ................................................................................ 5-4 Figure 6-1. Allowable Stress Criteria and Application Design Levels. ........................................................................................... 6-3 Figure A-1. Mathematical Model – Three Degree of Freedom System. ......................................................................................... A-1 Figure A-2. Free Body Diagram – Three Degree of Freedom System. .......................................................................................... A-2 Figure A-3. Mode Shapes, Three Degree of Freedom System........................................................................................................ A-5 Figure B-1. Mathematical Model Representation of a Mast – Isometric View. ............................................................................. B-2 Figure B-2. Mathematical Model Representation of a Mast – View Looking Forward and View Looking Port. .......................... B-3 Figure D-1. Hypothetical Damage Surface. .................................................................................................................................... D-1 Figure D-2. Orientation of Equipment Axis with Respect to Ship Axis. ........................................................................................ D-2 Figure E-1. General Arrangement of Foundation. ........................................................................................................................... E-4 Figure E-2. Radar Test Set. .............................................................................................................................................................. E-5 Figure E-3. Transponder Set. ........................................................................................................................................................... E-6 Figure E-4. Scantling Drawing for the Foundation (image 1 of 7). ................................................................................................. E-7 Figure E-5. Scantling Drawing for the Foundation (image 2 of 7). ................................................................................................. E-8 Figure E-6. Scantling Drawing for the Foundation (image 3 of 7). ................................................................................................. E-9 Figure E-7. Scantling Drawing for the Foundation (image 4 of 7). ............................................................................................... E-10 Figure E-8. Scantling Drawing for the Foundation (image 5 of 7). ............................................................................................... E-11 Figure E-9. Scantling Drawing for the Foundation (image 6 of 7). ............................................................................................... E-12 Figure E-10. Scantling Drawing for the Foundation (image 7 of 7). ............................................................................................. E-13 vii

Figure No. and Title Page

Figure E-11. Structural Model of Foundation. ............................................................................................................................... E-14 Figure E-12. Structural Model of Foundation. ............................................................................................................................... E-15 Figure E-13. Structural Model of Foundation. ............................................................................................................................... E-16 Figure E-14. Modal Analysis Results (with Closely Spaced Modes). ........................................................................................... E-22 Figure E-15. Results Comparison of Closely Spaced Modes (Participation Factor Times Mode Shape). .................................... E-23 Figure E-16. Modal Analysis Results without Closely Spaced Modes. ......................................................................................... E-24 Figure G-1. Bolt Securing a Bracket to a Support Plate. ................................................................................................................ G-1 Figure G-2. Bolt Securing a Bracket to a Support Plate with 1-Pound Load. ................................................................................. G-2 Figure G-3. Model of a Bolt. .......................................................................................................................................................... G-2 Figure G-4. Model of a Preloaded Bolted Joint. ............................................................................................................................. G-3 Figure G-5. Preloaded Bolt with Load. ........................................................................................................................................... G-4 Figure G-6. Bolt and Joint Displacement Diagrams. ...................................................................................................................... G-5 Figure G-7. Joint Diagram. ............................................................................................................................................................. G-5 Figure G-8. Joint Diagram with Applied Force. ............................................................................................................................. G-6 Figure G-9. Joint Diagram for a Hard Joint. ................................................................................................................................... G-7 Figure G-10. Joint Diagram for a Soft Joint. .................................................................................................................................. G-7 Figure G-11. Typical Bolt Connection. .......................................................................................................................................... G-8 Figure G-12. Joint Configuration. ................................................................................................................................................. G-10 viii

LIST OF TABLES

Table No. and Title Page

Table E-1. Modal Analysis Results With Closely Spaced Modes. ................................................................................................ E-21 Table E-2. Modal Analysis Results without Closely Spaced Modes. ............................................................................................ E-21 Table F-1. Example Applications of the Allowable Stress Criteria. ................................................................................................ F-1 Table F-2. Special Applications of the Allowable Stress Criteria.................................................................................................... F-8 ix/(x blank)

FOREWORD

The purpose of Design Practices and Criteria (DPC) Manuals is to provide ship design practices and criteria to personnel involved with the design, conversion, or modernization of U.S. Navy ships. This Manual is therefore part of a library of DPC Manuals. A listing of all DPC Manuals and other ship design documents can be found in the DPC Index

(NAVSEA T9070-AE-DPC-010/001-1).

This document is intended to provide design guidance for surface ship equipment and foundations subject to underwater explosions. The design process defined in this document, used for contractual shock qualification, involves the use of confidential data, T9070-AJ-DPC-010/(C) 072-1 (formerly DDS 072-1), which must be manipulated within a proper secure environment.

This document is organized as follows:

Chapter 1, Introduction

Chapter 2, Applicable Documents

Chapter 3, Dynamic Design Analysis Method

Chapter 4, Foundation Shock Design

Chapter 5, DDAM of Grade B Items

Chapter 6, Allowable Stress Criteria

Chapter 7, Dynamic Shock Analysis Review and Approval Procedures

Appendix A, Sample Computation of Normal Modes of a Structure

Appendix B, Finite Element Method for DDAM Analysis

Appendix C, Transient Analysis Methods

Appendix D, Oblique Directional Shock Inputs

Appendix E, Sample Finite Element DDAM Analysis – Format and Content

Appendix F, Example Application of the Allowable Stress Criteria

Appendix G, Bolt and Bolt Joint Design

Appendix H, List of Abbreviations, Acronyms, Symbols, and Definitions

All errors, omissions, discrepancies, and suggestions for improvement to NAVSEA and SPAWAR technical manuals (TMs) shall be submitted as a Technical Manual Deficiency/Evaluation Report (TMDER) via the NAVSEA/SPAWAR TMDER form, NAVSEA 4160/1, included at the back of this TM.

1-1/(1-2 blank)

CHAPTER 1

INTRODUCTION

1.1 PURPOSE.

The primary purposes of this manual are as follows:

a. Provide technically oriented shock design criteria for Navy review and approval of shock design calculations.

b. Provide a limited amount of general background/educational material concerning application of the Dynamic Design

Analysis Method (DDAM).

This manual is intended to convey Navy dynamic shock analysis requirements to engineers who possess an educational or experience background in the fields of vibration analysis, structural dynamics, and stress analysis. If the user finds that this manual does not provide information sufficient to permit full and efficient satisfaction of all specified dynamic shock analysis requirements, the cognizant contracting officer shall be contacted for additional information.

The requirements indicated by this manual are subject to modification by applicable specifications. Users of this manual shall carefully review applicable specifications to determine whether any of the provisions of this manual have been modified. The contents of this manual are founded upon dynamic analysis procedures originally developed by the Naval Research Laboratory (NRL), Washington, D.C.

2-1

CHAPTER 2

APPLICABLE DOCUMENTS

2.1 INTRODUCTION.

The documents listed in this chapter are specified in chapters 1-7 of this publication. This chapter does not include documents cited in other sections of this publication. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements documents cited in chapters 1-7 of this publication, whether or not they are listed.

2.1.1 Government Publications.

DEFENSE SPECIFICATIONS

MIL-DTL-1222 - Studs, Bolts, Screws and Nuts for Applications where a High Degree of Reliability is Required; General Specification for

(Copies of this document are available online at http://quicksearch.dla.mil.)

DEPARTMENT OF DEFENSE ISSUANCES

DoDI 5000.61 - DoD Modeling and Simulation (M&S) Verification, Validation, and Accreditation (VV&A)

(Copies of this document are available online at www.dtic.mil/whs/directives/.)

GUIDANCE MANUALS

Report No. SUPSHIP 280-1 - Mathematical Model and Dynamic Shock Analysis Guide for Main Propulsion Shafting

Report No SUPSHIP 280-2 - Mathematical Model and Dynamic Shock Analysis Guide for Rudders, Rudder Stock and Bearings

Report No. SUPSHIP 280-3 - Mathematical Model and Dynamic Shock Analysis Guide for Main Reduction Gear

Report No. SUPSHIP 280-6 - Mathematical Model and Dynamic Shock Analysis Guide for Masts

(Copies of these documents are available from Naval Surface Warfare Center Philadelphia Division (NSWCPD) Code 333, WPN STA Earle, Bldg C38, 201 State Route 34 South, Colts Neck, NJ 07722.)

NAVSEA TECHNICAL PUBLICATIONS

T9070-AJ-DPC-010/(C) 072-1 - Shock Design Values

T9070-AN-DPC-040/100-4 - Strength of Structural Members

(T9070-AJ-DPC-010/(C) 072-1 is a classified document with controlled distribution. Requests for this document, supported by a verifiable need-to-know, shall be submitted to commandstandards@navy.mil.)

(Copies of T9070-AN-DPC-040/100-4 are available online via Technical Data Management Information System (TDMIS) at https://mercury.tdmis.navy.mil/ by searching for the document number without the suffix. Refer questions, inquiries, or problems to: DSN 296-0669, Commercial (805) 228-0669. This document is available for ordering (hard copy) via the Naval Logistics Library (NLL) at https://nll.ahf.nmci.navy.mil.