ASTM D7137 - Compressive Residual Strength Properties of Damaged Polymer Matrix Composite Plates

 

ASTM D7137 measures the compression strength of multidirectional composite coupons which have been previously subjected to an indentation according to test method ASTM D6264/D6264M, or drop-weight impact in accordance with test method ASTM D7136/D7136M. ASTM D7137 is mainly used by the aerospace industry to produce compressive property data for material specifications, research and development, quality assurance, and structural design and analysis. 

Damage from out-of-plane forces is a major concern for design engineers working with composite materials. The impact portion of this test method simulates damage that the material is expected to incur in the field, such as a tool being dropped onto the surface of a plane during maintenance or a bird hitting the plane's wing. ASTM D7137 testing is important because the compressive strength of a composite plate is reduced even when an impact is not sufficient enough to cause visible damage. ASTM D7137 helps design engineers gain knowledge of the damage resistance and tolerance properties of composite plate. The desired test results are the ultimate compressive strength and the effective compressive modulus.  

Materials Testing System

The compression portion of ASTM D7137 should be performed on a high force universal testing system such as Instron's 6800 Series equipped with an an AlignPro fixture and a custom compression after impact fixture. The material must first be subject to ASTM D7136/D1736M testing on an impact system such as Instron's 9400 Series drop towers. Drop towers must have an anti-rebound device to prevent a secondary impact.