Thermodynamic behavior of NiTi shape memory alloy against low-velocity impact: experiment and simulation

The study of thermodynamic behavior of shape memory alloy (SMA) against impact is of great importance for the use of SMA as damping devices. This paper investigates the thermodynamic behavior of NiTi SMA sheet subjected to low-velocity impact loading, by means of experiment and explicit finite element (FE) analysis. First, the impact tests are carried out with different impact energies on the drop-weight impact system, the thermal response during the impact process is captured by the infrared camera. The impact force and the temperature rise achieve the maximum values of 8716 N and 46.93 ^∘C at impact energy of 25 J. Then, an explicit Euler integration scheme is introduced to implement the SMA model (Wang et al., 2017, IJP) into finite element software ABAQUS by means of the explicit user-defined material subroutine VUMAT. Finally, the impact tests are simulated using the proposed numerical algorithm. Numerical results show good correlation with the experimental data, the maximum deviations between both for the impact force and the temperature are 5.78% and 0.63%, respectively. The analysis approach captures the prime thermodynamic features of SMA against low-velocity impact load such as superelastic deformation, stress-induced martensite phase transformation and temperature variation.