1.1 This practice covers an approach for impacting and compressive testing thin multidirectional polymer matrix composite laminates reinforced by high-modulus fibers using a sandwich long beam flexure specimen. It provides a test configuration in which the core does not constrain any protruding backside impact damage. It is limited to testing of monolithic solid laminates that are too thin to be tested using typical anti-buckling fixtures. It does not cover compressive testing of impact-damaged sandwich panel facings. The composite material forms are limited to continuous-fiber or discontinuous-fiber (tape or fabric or both) reinforced composites in which the laminate is balanced and symmetric with respect to the test direction. 1.2 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 exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.2.1 Within the text, the inch-pound units are shown in brackets. 1.3 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 and health practices and determine the applicability of regulatory limitations prior to use.
Standard needed for unique testing requirements for thin laminates. To be used by industry to develop compression residual strength properties.
Keywordscomposite materials; compression after impact; compression testing; compressive residual strength; damage; bending stress; facing stress; facing strength; sandwich construction
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Ballot Item Approved as D7956-2014 and Pending Publication