Abstract and subjects
The assumption that Young's modulus is strain-rate invariant is tested for 6061-T6 aluminium alloy and 1018 steel over 10 decades of strain-rate. For the same billets of material, 3 quasi-static strain-rates are investigated with foil strain gauges at room temperature. The ultrasonic sound speeds are measured and used to calculate the moduli at approximately 10(4) s(-1). Finally, ID plate impact is used to generate an elastic pre-cursor in the alloys at a strain-rate of approximately 10(6) s(-1) from which the longitudinal sound speed may be obtained. It is found that indeed the Young's modulus is strain-rate independent within the experimental accuracy.