Effect of Strain-rate and Temperature on the Mechanical Properties of ABS Resin

Abstract

As a result of the increase in demand for an impact resistance of polymer moldings, many attempts have been made to characterize their behaviour using CAE method. However, the use of a constant Young's modulus or yield stress in CAE method introduces significant errors under the high strain-rates caused by impact or drop situation.
In this study, we investigate the effect of strain-rate and temperature on the mechanical properties of ABS resin. A standard tensile testing machine with crosshead speeds from 0.2 to 500mm/min was used to observe the tensile and compressive behaviour. A Hopkinson test apparatus was used to observe the compressive behaviour under high strain-rate conditions.
Additionally, the effect of varying ambient temperature (from 0 to 60°C) on mechanical properties was investigated.
From these experiments following results are obtained.
(1) Even under low strain-rate region the effect of strain-rate on yield-stress is remarkable. And the yield stress can be expressed as a exponential function of strain-rate.
(2) It can be expected that the mechanism of deformation between tensile and compression were different. Especially the stress was increased after yielding at tensile test, but such phenomenon was not observed at compression test.
(3) The stress-strain curves were similar to that of low strain rate under the impact compression. The relationship between the yield stress and strain can be also expressed by a exponential function as stated (1) among the wide range of strain-rate.