ASTM C365 –  Sandwich Core Compression Testing

ASTM C365 – This test method covers the determination of compressive strength and modulus of sandwich cores.

These properties are usually determined for design purposes in a direction normal to the plane of facings as the core would be placed in a structural

sandwich construction.

The test procedures pertain to compression in this direction in particular, but also can be applied with possible minor variations to determining compressive

properties in other directions.

Permissible core material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding

surfaces (such as honeycomb).

*** This test method does not cover the determination of compressive core crush properties. Reference Test Method D7336/D7336M

 for determination of static energy absorption properties of honeycomb sandwich core materials.

Significance and Use

Flatwise compressive strength and modulus are fundamental mechanical properties of sandwich cores that are used in designing sandwich panels.

Deformation data can be obtained, and from a complete force versus deformation curve, it is possible to compute the compressive stress at any applied force

(such as compressive stress at proportional limit force or compressive strength at the maximum force) and to compute the effective modulus of the core.

*** This test method provides a standard method of obtaining the flatwise compressive strength and modulus for sandwich core structural

design properties, material specifications,  research and development applications, and quality assurance.

*** Before conducting ASTM C365 , it is important to read the entire specification. Standards can be obtained from appropriate standard authorities.