loading and unloading test

• 加卸载

loading and unloading test的用法和样例：

例句

1. The response velocity of transducer was measured by the laser Doppler vibrometer.The loading and unloading process were analyzed and modeled in three segments.
   据此对超声加卸载过程分段，进行频谱分析和非稳态特性建模，并研究了相关的试验方法。