Yaw angle effect on flat plate impact and its critical value analysis

Flat plate impact experiments are crucial in assessing the dynamic mechanical properties of materials. However, yaw angle tolerances always affect the accuracy of the results. To analyze this effect, this study conducted numerical simulations and theoretical derivations of non-ideal plate impacts. By comparing the simulated results of spallation, shock wave propagation, and free surface velocity, laws governing the effect of yaw angle on the plate impact were summarized. We observed that yaw angles influence the wave-action time and the shape of the compression zone, which affects the trigger and location of spallation and the free surface velocity of the target. Additionally, the yaw angle diminishes the kinetic energy of the target. When the yaw angle exceeds 2°, a significant energy reduction occurs as the shock wave propagates, which results in insufficient energy for complete spallation. Our analyses led to proposing methods for determining the critical yaw angle in plate impact experiments and to introducing a multipoint-velocimetry approach to calculate the non-ideal impact posture of the flyer. Notably, the findings revealed that 0.2° could serve as the critical yaw angle in certain scenarios. Leveraging these research outcomes judiciously can aid in assessing experimental deviations effectively and optimizing experimental costs.