Verification of a multiple-machine program for material testing from quasi-static to high strain-rate

• A multiple-machine program consisting of different facilities is verified.
• Measurement approaches are assessed to guarantee reliability.
• Verification scheme 1 is executed with tests of a rate insensitive aluminum alloy.
• Verification scheme 2 is executed with tests of a rate dependent steel material.

Nowadays characterization of the strain-rate dependence of materials becomes indispensable in crashworthiness design of structures (i.e. car-bodies, ships) with CAE approach. To gather sufficient test data for accurate characterization, various machines are usually selected to work together on material testing covering quasi-static, intermediate and high strain-rates, which is referred to as a multiple-machine program in the present paper. Relatively rigorous verification of the multiple-machine program, including two test schemes, was designed and executed to ensure the comparability of test data from various machines. First, an acknowledged rate-insensitive aluminum alloy material was tested with a universal material test machine, an intermediate strain-rate test machine and a drop tower, respectively. Second, a rate-dependent high-strength steel material was tested with the same multiple-machine program, focusing on two strain-rate overlaps. Rate sensitivities of the tested materials were demonstrated by the test results in the two test schemes, and consistencies of the test data in the strain-rate overlaps were satisfactory, strongly verifying reliability of the multiple-machine program. Crucial measurement approaches were also decided prior to the verification, including the DIC method for deformation measurement and the dynamic force measurement to attenuate the ringing effect.