ASTM D6790/D6790M-14

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 standard methods.

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

5.3 Factors that influence the Poisson’s 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 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

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.