异形子弹校准高g值加速度计的数值模拟

Numerical Study on Abnormity Bullets with High g Accelerometer Calibration

高g值加速度计是MEMS技术应用于高速撞击/冲击过程中冲击载荷测量的关键之一,现今主要采用微型霍普金森压杆技术对高g值加速度计进行动态校准。该技术中应力波的整形方法主要有采用波形整形器与改变冲击子弹形状两种。采用有限元分析软件ABAQUS对采用异形子弹获得的加载波形及压杆自由端上的加速度信号进行数值模拟研究。模拟结果表明:柱锥形子弹锥高与应力波峰值、下降沿时及加速度峰值成负相关,其应力波形均为类正弦波;而圆锥形子弹锥高与应力波峰值、下降沿时及加速度峰值成负相关,且锥高越小应力波型越趋于类正弦波;子弹的质量与应力波峰值、加速度值成正相关。

High g accelerometer is influential for using MEMS technology in the impact load measurement of high speed collision or impact process. Now micro-Hopkinson pressure bar technique is mainly adopted for high g accelerometer dynamic calibration. The shaping technologies of stress wave include using pulse shapers and changing the shape of impact bullets.Using the finite element analysis software ABAQUS to carry on numerical simulations for using abnormity bulletsto shape incident waveform,and the accelerations on the free end are obtained. Simulation results show that the cone height of conicalcylindrical bullet has negative correlation relationship with the peak value of stress wave,the falling edge and the peak value of acceleration,and all the incident stress waves produced are approaching sine wave. And the cone height of conic bullet also has negative correlation relationship with the peak value of stress wave,the falling edge and the peak value of acceleration,and the smaller the cone heightthe stress wave type is more approaching sine wave. There are positive correlation between the bullet mass and stress wave peak value and acceleration peak value.