ASTM D7291/D7291M-22

5.1?This test method is designed to produce through-thickness failure data for structural design and analysis, quality assurance, and research and development. Factors that influence the through-thickness tensile strength, and should therefore be reported, include the following: material and fabric reinforcement, methods of material and fabric preparation, methods of processing and specimen fabrication, specimen stacking sequence, specimen conditioning, environment of testing, specimen alignment, speed of testing, time at temperature, void content, and volume reinforcement content.

1.1?This test method determines the through-thickness flatwise tensile strength and elastic modulus of fiber reinforced polymer matrix composite materials. A tensile force is applied normal to the plane of the composite laminate using adhesively bonded thick metal end-tabs. The composite material forms are limited to continuous fiber (unidirectional reinforcement or two-dimensional fabric) or discontinuous fiber (nonwoven or chopped) reinforced composites.

1.2?The through-thickness strength results using this test method will in general not be comparable to Test Method D6415 since this method subjects a relatively large volume of material to an almost uniform stress field while Test Method D6415 subjects a small volume of material to a non-uniform stress field.

1.3?UnitsThe 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.

1.4?This standard may involve hazardous materials, operations, and equipment.

1.5?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.

1.6?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.