5.1 This test method is designed to produce inplane shear property data for material specifications, research and development, quality assurance, and structural design and analysis. Factors that influence the inplane shear response and should therefore be reported are material, method of material preparation, specimen preparation, specimen conditioning, environment of testing, specimen alignment and gripping, speed of testing, void content, and fiber volume fraction. Properties, in the test direction, that may be obtained from this test method are as follows:

5.1.1 Inplane Shear Strength, τ₁₂^u,

5.1.2 Inplane Shear Strain at Failure, γ₁₂^u , and 

5.1.3 Inplane Shear Modulus, G₁₂.

1.1 This test method determines the inplane shear properties of wound polymer matrix composites reinforced by high-modulus continuous fibers. It describes testing of hoop wound (90°) cylinders in torsion for determination of inplane shear properties.

1.2 The technical content of this test method has been stable since 1993 without significant objection from its stakeholders. As there is limited technical support for the maintenance of this test method, changes since that date have been limited to items required to retain consistency with other ASTM D30 Committee standards, including editorial changes and incorporation of updated guidance on specimen preconditioning and environmental testing. The test method, therefore, should not be considered to include any significant changes in approach and practice since 1993. Future maintenance of the test method will only be in response to specific requests and performed only as technical support allows.

1.3 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.3.1 Within the text, the inch-pound units are shown in brackets.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.