SPEC_EB-4941.pdf

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I ,-::'941 I I!FI'1!:C'I1VE DATIl

September 30, 2011

SIIIP OR PIIIOJICT NO.

VIRGINIA Class Qualification of Glaaa Reinforced Plastic ComDosite Material SYstems PAS. NO. 10F 24 PAGD

ELECTRIC BOAT CORPORATION APPROVALS OTHER APPROVALS

DATI

Rev. A, PMS450 per Letter

DATE

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A. Sprecace Rev. B, PMS450 per Letter Ser 450T4G/0706 21 Sep 11

J. Tyropolis M~ v 1/' REVISIONS

DATE DATI

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Rev.C Electric Boat Specification No. 4941

QUALIFICATION OF

GLASS REINFORCED PLASTIC

COMPOSITE MATERIAL SYSTEMS

-2

RECORD OF REVISION

Rev. A September 30,2010

Rev.B July 20, 2011

Rev.C September 30, 2011

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Rev. C Electric Boat Specification No. 4941

TABLE OF CONTENTS

PARAGRAPH PAGE NO.

1.0 SCOPE 5

2.0 APPLICABLE DOCUMENTS 6

3.0 CLASSIFICATION 8

4.0 REQUIREMENTS 9

5.0. QUALIFICATION 14

6.0. QUALITY ASSURANCE 16

7.0. RAW MATERIAL CONTROL AND DELIVERY 22

TABLES

L Typical E-Glass Fabrics and Suppliers 8

2. Typical Resin Systems and Suppliers 8

3A. Vendor Qual. Laminate Mechanical Props. for Warps Parallel Lay-Up 11

3B. Vendor Qual. Laminate Mechanical Props. for Quadraxial or Quasi-Isotropic Lay-Up 12

4. Number of Test Specimens for Each Test and Batch 18

FIGURES

1. SACMA Tension Strength Test Specimen 23

2. SACMA Compression Strength Test Specimen 23

3. ASTM D5379 Interlaminar Shear Test Through Thickness Configuration 24

4. Mode I Fracture Toughness Test Specimen 24

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1. SCOPE

1.0 Scope

This specification establishes the requirements for acceptable E-Glass reinforced plastic composite material systems intended for use in fabricating structures and components which are external to submarine pressure hulls. Vendors currently unconditionally qualified to use a particular material system and process under a different specification will remain qualified for that material system and process.

Vendors currently not qualified to use a particular material system and process, or conditionally qualified to a different specification, are encouraged to qualifY (and may be required to qualifY for future composite submarine component designs) to this specification.

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2. APPLICABLE DOCUMENTS

2.0 Issues of Documents

Unless otherwise specified, the following documents are applicable to the extent referenced herein. The revision of each document in effect on the date of issue of this specification shall be used, unless otherwise specified herein or approved by Electric Boat.

2.1 Government Documents

SPECIFICATraNS

Military

MIL-Y-1140 Yarns, Cord, Sleeving, Cloth and Tape-Glass

SAE-AMS-C-9084 Cloth, Glass, Finished, For Resin Laminates

MIL-HDBK-17 Composite Material Handbook

2.2 Other Publications

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

TEST PROCEDURES

ASTM D638 Tensile Properties of Plastics, Standard Test Method for

ASTM D695 Compressive Properties Rigid Plastics, Standard Test Method for

ASTM D792 Density and Specific Gravity (Relative Density) of Plastics by Displacement, Standard Test Method for

ASTM Dl141 Preparation of Substitute Ocean Water, Standard Practice for the

ASTM D2288 Weight Loss of Plasticizers on Heating, Standard Test Method for

ASTM D2584 Ignition Loss of Cured Reinforced Resins, Test for

ASTM D2734 Void Content of Reinforced Plastic, Standard Test Methods for

ASTM D3846 In-Plane Shear Strength of Reinforced Plastics, Test for

ASTM D4029 Finished Woven Glass Fabrics, Standard Specification for

ASTM D4255 In-Plane Shear Properties of Polymer Matrix Composite Materials by the Rail Shear Method, Standard Test Method for

ASTM D5379 Shear Properties of Composite Material by the V-Notch Beam Method, Standard Test Method for

ASTM D5528 Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Components, Standard Test Method for

ASTM D596 I Bearing Response of Polymer Matrix Composite Laminates, Standard Test Method for

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SUPPLIERS OF ADVANCED COMPOSITE MATERIALS ASSOCIATION (SACMA)

TEST PROCEDURES

SACMA 4R-94 SACMA Recommended Test Method fo Fiber-Resin Composite r Tension Properties of Oriented

SACMA IR-94 SACMA Recommended Test Oriented Fiber-Resin Composite

Method for Compression Properties of

2.3 Order ofPrecedence

In the event of a conflict between the text of this specification and the references cited herein, the text of this specification shall take precedence.

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3. CLASSIFICATION

3.0 General Classification

Classification of materials covered by this specification shall adhere to the following requirements.

3.1

Examples of types of standard E-Glass fabric reinforcements covered by this document are identified in Table 1. However, alternate fabrics are permitted so long as the applicable minimum average and B Basis values specified in Tables 3A or 3B, as appropriate, are met by the testing and conditioning requirements of this specification. The Vendor shall maintain current Material Safety and Data Sheets (MSDS) for all materials used in the Vendor's process and shall make such information available to Electric Boat upon request.

Table 1 - Typical E-Glass Fabrics and Suppliers

Fabric Type Sizing Supplier

24 oz. WR - Seemann Composites Inc.

35+3%/S/S - Gurit (SPRINT)

3783 F8I HEXCEL

3783 497A BGF Industries

3783 627 BGF Industries

3.2 Resin System

Examples of resin systems that have the potential to meet the requirements of this specification are listed in Table 2. However, alternate resins are permitted so long as the applicable minimum average and B Basis values specified in Tables 3A or 3B, as appropriate, are met by the testing and conditioning requirements of this specification. The Vendor shall maintain current MSDSs for all materials used in the Vendor's process and shall make such information available to Electric Boat upon request.

Table 2 Typical Resin Systems and Suppliers

Resin Type Supplier STVES Toughened Vinyl Ester Seemann Composites Inc.

SC15 or SC780 Toughened Epoxy Applied Poleramics PM24-27 Toughened Epoxy Goodrich EPP

ST94 Toughened Epoxy Gurit (SPRINT) Toughened Derakane 8084 Toughened Vinyl Ester Ashland Inc.

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4. REQUIREMENTS

4.0 Terminology

Some key terms used in this specification are defined below.

ANOVA A statistical analysis of variance test used to determine if two or more groups may be considered equal.

Anderson Darling Coefficient

B-Basis

Batch/Fabric

BatchlResin

Composite

Fill:

Laminate

Lot

Quadraxial:

Quasi-Isotropic:

Roving

Selvage

A coefficient used to describe how closely a data set fits a normal distribution curve (lower values are closer to fitting the curve).

A mechanical property value of a material that has 90% of all test values falling higher than it, with a confidence level of 95%

Fabric woven from one warp yarn set up with warp and fill meeting MIL-Y 1140 and/or SAE-AMS-C-9084 and/or ASTM 04029 requirements or Electric Boat approved equivalent.

Resin mixed in one mixer in one operation or blended together in one homogeneous mix with traceability to individual component lots.

Two or more different materials which when combined, retain their identities and do not dissolve or merge completely into one another, and produce properties which cannot be achieved by any of the components alone.

Transverse yarns oriented 90° to the warp of the glass fabric reinforcements.

A product made by consolidating multiple individual fiber plies within a resin matrix.

A specific amount of resin produced at one time using the same process and conditions of manufacture, and offered for sale as a unit quantity.

Fabric containing 0°, +45°, 90°, -45° glass reinforcements, with equal fiber fractions in each direction

A glass architecture layup of [00/+45°/900/-45°]NS or equivalent

Yarns, strands, tows, or ends assembled into a parallel bundle with minimal or no twist.

The woven-edge portion of a fabric parallel to the warp.

Traveler Specimen

A piece of a test specimen used to measure other material properties (e.g., moisture absorption).

Warp: Yarn oriented lengthwise (roll direction) in a glass fabric (0° direction).

Yarn A collection of filaments, fibers, or strands, twisted to form a continuous length that is suitable for weaving.

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4.1 General Requirements

Fabricated parts furnished under this specification shall be supplied to Electric Boat by Vendors only after the Vendor's materials have been tested and shown to meet the requirements of this specification.

In addition, material furnished under this specification shall also be supplied when requested by Electric Boat. Once the Vendor is qualified to this specification using a specific E-Glass fabric from a particular material supplier and a specific resin system, no change in raw material or Vendor's fabrication process will be allowed without formal notification to, and approval from, Electric Boat. In such cases the Vendor may have to qualify the new material systems. All test specimens prepared in support of this specification shall be in accordance with the latest ASTM revision or equivalent test methods approved by Electric Boat.

4.2 WarplFill Alignment

The alignment of warp and fill roving/yarn shall be perpendicular to each other and shall be parallel to the warp and fill directions of the fabric. Any deviation from this alignment shall not exceed ±3°. Areas not conforming to the above requirements are skewed and shall be either reworked to conform to these requirements or flagged as defective.

4.3 Laminate Mechanical Properties

As-cured mechanical properties of the laminate shall meet the requirements listed in Tables 3A or 3B, as appropriate. All values listed are requirements unless otherwise specified therein. If architectures other than those specified in the tables are used for Vendor qualification, details of the material form and the characterization test matrix shall be submitted to Electric Boat for approval prior to conducting tests.

Vendors qualifying to this specification using quadraxial or quasi-isotropic test panels shall only be qualified to manufacture quadraxial or quasi-isotropic production parts.

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Rev. C Electric Boat Specification No. 4941

Table 3A - Vendor Qualification Laminate Mechanical Properties for e ay-UpWarps ParalllL

Property Requirement B-Basis Min.

(Section 6.3.3( e))

Requirement Min. Average

Test Method Comments

Tensile Strength, psi warp, dry* warp, wet** fill, dry fill, wet

42,000 35,000 34,000 30,500

48,000 39,000 42,000 32,000

ASTMD638

Type III

SACMA 4R-94 Test Method may be substituted

Tensile Modulus, x 106 psi warp, dry* fill, dry* warp, wet** fill, wet**

NR

NR

NR

NR

(Information Only) 3.4 3.2 3.1 3.0

ASTMD638

Type III

SACMA 4R-94 Test Method may be substituted

Compression Strength, psi warp, dry* warp, wet** fill, dry* fill, wet**

42,000 35,000 34,000 30,500

48,000 39,000 42,000 32,000

ASTMD695 SACMA lR-94 Modified Test Method may be substituted

Bearing Strength (Ultimate), psi warp, dry* warp, wet**

47,000 40,000

49,000 43,000

ASTM

D5961

In-plane Shear Strength, psi at 5% Shear Strain dry * wet * *

6,700 6,200

7,500 6,600

ASTM

D4255

ASTM D5379 Test Method may be substituted

Interlaminar Shear Strength, psi warp, dry* warp, wet**

6,000 5,500

7,400 6,500

ASTM

D3846

ASTM D5379 Test Method may be substituted

Mode I Fracture Toughness in.-Ibs. / in2

NA On-Set- 2.5 Propagation - 4.5

ASTMD5528

Fiber Volume, % NR 45 ASTMD2584 Resin Content by Weight, % NR 27-38 Par. 6.3.3.6 Void Content, %*** NR Less Than 1.0 ASTMD2734 or Image Analysis

Cured Specific Gravity NR 1.78-1.93 ASTMD792 Material property values based on data and analysis provided in Electric Boat letter 3411ATS/II-0690 of 15 Sep 11, with enclosures.

* Dry test conditioning shall be performed on unconditioned specimens tested at 70 OF ± 10 OF and 50% ± 10% relative humidity.

** Specimens for wet conditioning tests shall be immersed in synthetic seawater (ASTM D1141) at 160 OF for 14 days. Weight gain shall be measured and recorded from a 4 inch x 4 inch traveler specimen of equal thickness to panel.

*** Void contents in excess of 1.0% may be acceptable (subject to Electric Boat approval) provided all other properties meet their requirements.

NR Not Required

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Rev.C Electric Boat Specification No. 4941

Table 3B - Vendor Qualification Laminate Mechanical Properties for ua raxla or uaSI- sotropiC ay- IpQ d '1 Q'I 'L U

Property Requirement B-Basis Min.

!(Section 6.3.3(e))

Requirement Min. Average

Test Method Comments

Tensile Strength, psi dry'" wet*'"

34,000 25,000

38,000 30,000

ASTMD638

Type III

SACMA 4R-94 Test Method may be substituted

Tensile Modulus, x 10° psi dry'" wet"'''' l\;'R

NR

(Information Only) 2.4 2.3

ASTMD638

Type III

SACMA 4R-94 Test Method may be substituted

Compression Strength, psi dry'" wet"''''

34,000 25,000

38,000 30,000

ASTMD695 SACMA IR-94 Modified Test Method may be substituted Bearing Strength (Ultimate), psi dry'" wet*'"

52,000 43,000

53,000 45,000

ASTM

D5961

In-plane Shear Strength, psi at 5% Shear Strain dry'" wet*'"

15,000 13,000

16,000 14,000

ASTM

D4255

ASTM D5379 Test Method may be substituted

Interlaminar Shear Strength, psi dry * wet**

6,000 5,500

7,400 6,500

ASTM

03846

ASTM D5379 Test Method may be substituted

Mode I Fracture Toughness in.-Ibs.! in2

NA On-Set - 2.5 Propagation - 4.5

ASTMD5528

Fiber Volume, % NR 45 ASTMD2584 Resin Content by Weight, % NR 27-38 Par. 6.3.3.6 Void Content, %"'** NR Less Than 1.0 ASTM D2734 or Image Analysis

Cured Specific Gravity NR 1.78-1.93 ASTMD792 Matenal property values based on data and analYSIS provIded In ElectrIc Boat letter 341/ ATS/ll-0690 of 15 Sep II, wIth enclosures. '

* Dry test conditioning shall be performed on unconditioned specimens tested at 70 of ± 10 of and 50% 10% relative humidity.

** Specimens for wet conditioning tests shall be immersed in synthetic seawater (ASTM 01141) at 160 OF for 14 days. Weight gain shall be measured and recorded from a 4 inch x 4 inch traveler specimen ofequal thickness to panel.

*** Void contents in excess of 1.0% may be acceptable (subject to Electric Boat approval) provided all other properties meet their requirements.

NR Not Required

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4.4 Process Control

Qualification panels fabricated to this material specification shall be prepared utilizing the composite fabrication process that the Vendor is trying to qualifY. The Vendor shall document and submit to Electric Boat, along with the qualification panel test results, information applicable to all steps in the fabrication process including: the materials (resin and fabric), lay-up, thickness, vacuum bagging techniques, infusion rates, cure cycle, and any post cure cycle, as appropriate, to the particular fabrication process. A thermocouple probe shall be installed at the mid thickness of each laminate to verifY the cure cycle and post cure cycle. Once the Vendor composite fabrication process and materials are qualified, no changes to that process are permitted without prior Electric Boat approval.

4.5 Storage Life

Any resins, catalysts, initiators, hardeners, and promoters, used in fabrication of qualification panels, concurrent panels or production parts, shall be stored in their original labeled containers and tagged with the original manufacturer's expiration date. The Vendor shall not use any resin, catalyst, initiator, hardener, or promoter, which has exceeded the manufacturer's expiration dates.

4.6 Workmanship

The as-cured composite material shall be uniform in quality and construction, and free from any impurities and other defects that could adversely affect its appearance and performance. The Vendor shall implement appropriate fabrication techniques to eliminate resin-rich areas or comer voids caused by fiber or vacuum bag bridging.

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Rev. C Electric Boat Specification No. 4941

5. QUALIFICATION

5.0 Guidelines

The following guidelines shall be followed to ensure that the material is properly qualified:

(a) All requests for qualification shall be directed to Electric Boat D341 I Composites Engineering.

(b) Electric Boat reserves the right to require that all individual coupon test samples be provided for review.

(c) Qualification will require submittal of individual coupon test data and minimum average and B-Basis calculations indicating compliance with the material requirements of this specification for the material and fabrication process being qualified.

(d) The qualification samples shall be cut from qualification test panels made from two (2) separate independent glass and resin batches and must be fabricated in the Vendor's shop environment using the same methods as those for production parts. Sufficient panels shall be fabricated with each independent batch to perform all of the testing described in Section 6.0 and Tables 3A or 3B, as appropriate. The mechanical strength data from the two batches shall be pooled or considered individually based on guidelines per MIL HDBK-17-1, Sections 8.3.2 and 8.3.5.2.6. For the case where the two test panel data sets cannot be pooled, the lower of the B-Basis values of all specimens, or of the individual batches, shall be used to indicate the B-Basis value for the material. Test specimens shall be cut from random locations to make them representative of the panel. Each laminate system with its associated fabrication process must be qualified individually.

(e) The qualification data submitted for approval shall be accompanied by a test report, in duplicate, which shows that the data analysis method and test values meet the requirements of this specification and that a laminate made from this material meets the requirements of Tables 3A or 3B, as appropriate.

The vendor qualification report must contain:

(1) Supplier product designation

• Fiberglass fabric

• Resin system

(2) Copy of certification from glass and resin supplier

(3) All glass fabric physical and mechanical properties provided by the fabric supplier

(4) Glass finish

(5) Glass type in accordance with this specification, per latest revision letter

(6) All resin physical and mechanical properties provided by the resin supplier

(7) Test results, including supporting test data

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Rev.C Electric Boat Specification No. 4941

(8) Fabrication process description in accordance with paragraph 4.4

(f) The Vendor shall perform additional tests deemed necessary by Electric Boat. The Vendor will be notified of any additional test requirements prior to qualification.

(g) In addition to meeting the physical and mechanical requirements of this specification, any new resin system or glass finish must be approved by Electric Boat prior to production use.

(h) All qualification test data will be generated by a test lab previously approved by Electric Boat, using test panels fabricated by the Vendor. The adequacy of test facilities may be verified as deemed necessary by Electric Boat, including but not limited to site visits.

(i) A Vendor shall not supply production grade components until qualification to this specification has been approved by Electric Boat.

G) The vendor shall notify Electric Boat of any changes in product formulation, raw materials, raw material suppliers, manufacturing process, geographic manufacturing location, or replacement of any raw material with another equivalent raw material. Re qualification shall be required in each of the above instances unless otherwise specified by Electric Boat. Electric Boat may also request re-qualification as the result of other factors, at the discretion of Electric Boat.

(k) Repeating of any or all of the qualification tests required herein may be requested by Electric Boat at any time and the material must pass the qualification requirements.

Upon request from Electric Boat, the Vendor shall supply all remaining test panel material referenced herein in Section 5.0 paragraph (d).

(I) Suppliers seeking qualification to this specification shall submit to an audit of, but not limited to, their product manufacturing operations, raw material traceability, process records, test procedures, and quality assurance records. If deemed necessary by the Vendor, Electric Boat will enter into a nondisclosure agreement with the Vendor, to protect the proprietary rights of both parties. Electric Boat reserves the right to perform a re-audit in support of any or all orders subsequent to qualification.

(m) The supplier shall have on file, a Manufacturing and Quality Assurance Plan approved by Electric Boat and containing baseline chemistry, manufacturing process and in process test information.

(n) All Vendor's qualification costs, including qualification samples and testing thereof, shall be at the Vendor's expense.

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6.3

Rev.C Electric Boat Specification No. 4941

6. QUALITY ASSURANCE

6.0 Responsibility for Inspection

The Vendor is responsible for the performance and reporting of all inspection and testing requirements as specified herein. Electric Boat reserves the right to witness or perform any of the inspections or tests set forth in this specification where such tests and inspections are deemed necessary to ensure that material and services conform to the prescribed requirements.

6.1 [Not Used]

6.2

Qualification requirements for material properties are provided in Paragraph 4.3. Electric Boat D3411Composites Engineering and D323/Quality Assurance will evaluate the test parameters on all incoming material which fails to meet the requirements identified herein, and establish if additional tests are required to determine the integrity of the material for its acceptance or rejection.

The vendor shall employ the following test methods.

6.3.1 Examination of Material

Material shall be examined to determine conformance to this specification with respect to workmanship and construction per Section 4.

6.3.2 Resin Content and Glass Basic Weight

Resin content, % by weight, shall be tested per the following procedures:

(a) Volatile content measurements are to be performed in accordance with ASTM D2288. Report volatile content individually and average value to the nearest 0.1%.

(b) Use the 3 specimens from the previously run volatiles test, Paragraph 6.3.2 (a), and place them into tarred porcelain crucibles. Place specimens into a preheated muffle furnace stabilized at 1050 OF (±50 OF) for a minimum of30 minutes, or as required for complete burn out of the resin.

(c) After the resin has been completely burned out, remove the specimens from the oven, cool to ambient temperature in the desiccator and weigh to the nearest

0.001 gram.

(d) Calculate resin content per Equation 1.

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Rev. C Electric Boat Specification No. 4941 w-w Resin Content, % = 1 2 X 100 (1)

W

Where: W = Original weight of specimen, grams

WI = Weight of specimen with volatiles removed, grams, per Paragraph 6.3.2 (a)

W2 = Final weight of specimen after ignition, grams, per Paragraph 6.3.2(c)

(e) Report resin content individual and average values to the nearest 0.1 percent.

(f) Report the individual and average values of W2 to the nearest 0.01 gram as the glass basic weight.

6.3.3 Specimen Preparation and Test

Laminate test specimens general requirements are as follows:

(a) Machine all mechanical test specimens to 0° (within ±1.00) of the indicated reinforcement direction.

(b) Dry or standard conditioning shall be 70 of ±10 of with 50% ±10% relative humidity.

(c) Wet test conditioning specimens shall be immersed in synthetic seawater in accordance with ASTM D 1141, at 160 of for 14 days.

(d) Report individual and average test values.

(e) The B-Basis calculation shall be performed in accordance with the methodology outlined in MIL-HDBK-17 with the following exception:

Only Wei bull or Normal distributions shall be considered for B-Basis calculation if the data is poolable (i.e. the calculated Anderson Darling Coefficient exceeds the critical Anderson Darling Coefficient). The Weibull and Normal distribution with the higher observed significance level (OSL) for goodness-of-fit shall be used. In the event that the data is not poolable, the lower of the Weibull, Normal or ANOVA B-Basis values of all test data from the two batches or the lower of Weibull or Normal B-Basis values for the individual batches shall be used.

(f) Table 4 outlines the required number of test specimens for each test and each batch.

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Rev. C Electric Boat Specification No. 4941

Table 4 - Number of Test Specimens for Each Test and Batch

Test Dry Wet Batches Specimens/

Batch Batches Specimens/

Batch

Fiber Vol./Spec. Density, Void Content 2 5 N/A N/A Tensile Strength, Warp (0°) 2 5 2 5

Tensile Modulus, Warp (0°) 2 5 2 5

Tensile Strength, Fill (90°) 2 5 2 5 Tensile Modulus, Fill (90°) 2 5 2 5

Compression Strength, Warp (0°) 2 5 2 5

Compression Strength, Fill (90°) 2 5 2 5

Bearing Strength, Warp (0°) 2 5 2 5

In-Plane Shear Strength 2 5 2 5

Interlaminar Shear Strength, Warp (0°) 2 5 2 5

Mode I Fracture Toughness, Warp ( 0°) 2 5 N/A N/A

6.3.3.1 Tensile Strength and Modulus - ASTM D638 (or SACMA 4R-94)

(a) For qualification testing, a total of ten (10) dry and ten (10) wet ASTM D638 Type III configuration specimens will be required (with five (5) specimens from each batch) for both the warp and fill directions for a total of twenty (20) specimens for each direction. Specimen quantities identified shall apply to both modulus tests and strength tests. Cut specimens from the panel from random locations to make them representative of panel. The specimen configuration is identified in ASTM D638. If the SACMA 4R-94 test method is substituted, the specimen configuration is that shown in Figure I.

(b) When testing each specimen, use a crosshead rate of travel of 0.01 inch/minute until the initial straight-line portion of the stress-strain curve is obtained for modulus calculation (typically from 0.1 % to 0.3% strain). Rate may then be increased to 0.20-0.25 inch/minute until failure occurs.

6.3.3.2 Compression Strength - ASTM D695 (or SACMA IR-94)

(a) For qualification testing, a total often (10) dry and ten (10) wet ASTM D695 configuration specimens will be required (with five (5) specimens from each batch) for both the warp and fill directions for a total of twenty (20) specimens for each direction. Cut specimens from the panel from random locations to make them representative of panel. The specimen configuration is identified in ASTM D695. If the SACMA IR-94 test method is substituted, the specimen configuration is that shown in Figure 2. Note that if coarse (per ply thicknesses on the order of 0.030 inches) woven roving fiber reinforcements are used, Electric Boat may require the use of a specimen that is wider and thicker than that called out in the SACMA standard to ensure proper failure modes are obtained during the test. The test specimen tabs shall be bonded with an adhesive cured below the cure temperature for the composite material being tested.

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Rev.C Electric Boat Specification No. 4941

(b) Load the specimens at 0.05 inches per minute, +/- 0.010 inches per minute, until failure. Record the maximum load carried by the specimen during test.

(c) Specimens that fail at some obvious flaw within the material shall be discarded and a retest performed, unless such flaws constitute a variable whose effect is desired to be determined.

6.3.3.3 Bearing - ASTM D5961

(a) For qualification testing, a total often (10) dry and ten (10) wet ASTM D596l configuration specimens will be required (with five (5) specimens from each batch) from the warp direction for a total of twenty (20) specimens. Cut specimens from the panel in the warp or 0° direction and from random locations to make them representative of the entire panel.

(b) Each test specimen shall be prepared in accordance with ASTM D5961 and tested by Procedure A for tension loading. The specimen configuration is identified in ASTM D5961. The test value shall be reported at the ultimate strength for the test suite.

(c) Calculate the ultimate bearing strength per Equation 2.

P s = (2) b dt

Where: P = Ultimate (maximum) load, lbs.

d = Bearing hole diameter, inch t = Specimen thickness, inch

6.3.3.4a In-Plane Shear - ASTM D4255 (or ASTM D5379)

For qualification testing, a total of ten (10) dry and ten (10) wet ASTM D4255 configuration specimens will be required (with five (5) specimens from each batch) from the warp direction for a total of twenty (20) specimens. Cut in the warp or 0° direction and from random locations to make them representative of the entire panel. The specimen configuration is identified in ASTM D4255 or ASTM D5379, as appropriate.

6.3.3.4b Interlaminar Shear - ASTM D3846 (or ASTM D5379)

For qualification testing, a total of ten (10) dry and ten (10) wet ASTM D3846 configuration specimens will be required (with five (5) specimens from each batch) from the warp direction for a total of twenty (20) specimens. Cut specimens in the warp or 0° direction and from random locations to make them representative of the entire panel.

The specimen configuration is identified in ASTM D3846 or ASTM D5379, as appropriate. If ASTM D5379 is selected as the test method, a 0.75 in. thick panel is required with the specimens being cut through the thickness as shown in Figure 3.

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Rev.C Electric Boat Specification No. 4941

6.3.3.5 Mode I Fracture Toughness - ASTM D5528

(a) For qualification testing, a total of ten (10) dry ASTM D5528 configuration specimens will be required (with five (5) specimens from each batch) from the warp direction for a total often (10) specimens.

(b) Prepare each test specimen in accordance with ASTM D5528. All specimens shall be machined to nominal dimensions of 6.0 x 1.0 inches with a 0.0005 inch thick teflon insert extending along the laminate mid-plane a distance of 3.0 inches from the finished end of the specimen (2.0 inches from the hinge loading point). The 6.0-inch edges of the samples shall be surface ground to provide a smooth finish for viewing crack propagation. Piano hinges shall be bonded to each sample using a room temperature cure paste adhesive. Once the hinges are positioned and clamped to the specimens, the adhesive shall be allowed to cure at room temperature for a minimum of 24 hours. Figure 4 shows the double cantilever beam (DCB) specimen geometry.

Compute three values of critical strain energy release rate (G1c) as follows: The "visual onset" value corresponds to the initiation of crack growth verified visually using a 14X or greater microscope. The visual onset value is typically observed prior to achieving maximum load. The "maximum load" value corresponds to the maximum load achieved during the test. The point at which the maximum load is achieved will depend on the amount of crack branching, fiber bridging, etc. The "propagation" or "steady state" value is an average of the G1C values computed for crack lengths between 2.0 and 3.0 inches at intervals of 0.05 inches.

The three Grc values described above shall be computed using the "compliance calibration" method of data reduction in accordance with ASTM D5528, Sec.

12.1.2.

6.3.3.6 Test of Fiber Volume Fraction

Fiber volume measurements shall be performed in accordance with ASTM D2584. Bum out shall be performed for 6 hours minimum at 1050 OF for complete vaporization of the resin. Void content calculations shall be performed in accordance with ASTM D2734.

The fiber density and resin density value used when calculating laminate fiber volume and void content shall be obtained from the material supplier. If such values are not available from the material supplier, they shall be independently determined by the Vendor. In such cases, the resin density value shall be established from measurement performed in accordance with ASTM D792. The fiber density value shall be established from measurement observed during residual fabric from the ignition loss tests using a helium pycnometer or equivalent.

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6.4 Process Records

The Vendor is responsible for maintaining process and test data records for the qualification material tested for a minimum of 5 years from the date of material cure, unless otherwise specified. The records shall include all those tests, controls and sources of raw materials used during the qualification process.

6.5 Rejection

Failure of the cured material to conform to the requirements of this specification shall be considered cause for rejection.

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7. RAW MATERIAL CONTROL AND DELIVERY

7.1 Marking of Container

Each raw material container shall be permanently and legibly marked with the following information:

(a) Manufacturer's name

(b) Manufacturer'S lot number

(c) Expiration date

(d) Electric Boat specification number indicating latest revision

In addition, fiber constituent containers shall be marked with type of fiberglass material, glass finish and sIzmg. Containers for resin constituents and all additives (such as catalysts, initiators, promoters, hardeners) shall be marked with name of compound.

7.2 Packaging

Raw material containers shall conform to ICC shipping regulations or regulations of other common carriers as applicable to the mode of transportation. Each unit package shall be packed such that the material is protected from distortion and exposure to humidity or adverse weather conditions. Packaging shall also prevent damage from normal handling, storage or shipping hazards.

f

0.75 t7S

--L 9.00I. .1

Figure 1 - SACMA Tension Strength Test Specimen (not to scale)

1.500

0.400 SIDE-TO-SIDE

±OOO5 (OFFSET)

3.180 -*.

±0.005 t

A

NOTES:

l. STRAIN COMPATIBLE TABBING MA'!ERIAL, 0.050 MINIMUM THICKNESS 0.070 NOMINAL.

2. SPEClMEN THICKNESS SHALL BE AS 0.40 inches.

3. "an must equal "b" TO Wfl1ITN 0,020

4, ALL DIMENSIONS IN INCHES

Figure 2 - SACMA Compression Strength Test Specimen (not to scale)

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1/ - F23

Figure 3 - ASTM D5379 Interlaminar Shear Test Through Thickness Configuration h

Figure 4 Mode I Fracture Toughness Test Specimen (not to scale)

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