Effect of Time Step Scale Factor Value on the Low Velocity Impact Numerical Simulation Results in LS-DYNA

The major focus of this investigation is to analyze the effect of the time step scale factor (TSSFAC) parameter value on the numerical simulation results obtained by LS-DYNA for glass fiber reinforced polymer (GFRP) composite laminates subjected to low velocity impact. The TSSFAC is a parameter in the CONTROL_TIMESTEP keycard. The numerical simulations are conducted for two impact velocities 1.5 m/s and 4 m/s. At 1.5 m/s impact velocity, the impactor rebounded, whereas at an impact velocity 4 m/s, the impactor perforated the GFRP composite laminate. The TSSFAC values considered for the numerical simulation are 0.001, 0.01, 0.1, 0.5, 0.6, 0.7, and 0.9. The TSSFAC values affected both numerical simulation accuracy and numerical simulation time. However, the extent of influence of TSSFAC is high for simulation time compared to the numerical simulation accuracy. The simulation time increased as the TSSFAC value decreased. It was found that the TSSFAC value 0.6 yielded minimum simulation time compared to other TSSFAC values. Further, the best correlation between experimental and simulation results is found for 0.6 TSSFAC value.