ASTM D6790/D6790M-22

5.1?Certain sandwich panel analyses require the Poisson's ratio of the honeycomb core. It is not possible to measure the honeycomb's Poisson's ratio by conventional methods.

5.2?This test method provides a standard method of determining the Poissons ratio of honeycomb core materials for design properties, material specifications, research and development applications, and quality assurance.

5.3?Factors that influence the Poissons ratio of honeycomb core materials and shall therefore be reported include the following: core material, methods of material fabrication, core geometry, core thickness, core thickness uniformity, cell wall thickness, specimen geometry, specimen preparation, and specimen conditioning.

1.1?This test method covers the determination of the sandwich honeycomb core Poisson's ratio from the anticlastic curvature radii; see Fig. 1.

1.2?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.

1.3?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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4?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.