数字动光弹性实验技术的研究与应用

The Study of Digital Dynamic Photo-elasticity Experiment and Its Application

采用激光和数字高速相机,建立了数字动光弹性实验系统。自行浇筑了环氧树脂光弹性平面模型材料,进行了简支梁三点冲击动光弹性实验。实验结果表明,数字动光弹性实验技术研究动态应力波的传播问题是可行的;落锤冲击动光弹性实验表明简支梁在受到冲击载荷作用时,在简支梁的支点处首先产生应力集中,随后在下部两支点的中间位置处出现较大的拉应力,这是三点冲击试验中裂纹起裂通常发生在两支点的中垂线上,并沿下边缘从下至上扩展的原因;随着动态应力波在模型内部的进一步平衡,简支梁模型内部的应力逐渐向"上压下拉"的静力平衡状态发生转变。

With laser and high-speed digital camera,digital dynamic photoelastic experiment system was established.On their own in the epoxy resin casting plane photoelastic model material,beam three impact dynamic photoelastic experiment was carried out.The experimental results show that it is feasible that the digital dynamic photoelastic experiment technology researches dynamic problem of propagation of stress wave.Drop hammer impact dynamic photoelastic experiments show that when beam is under to impact load,stress concentration appeared in beam fulcrum place first,then the large tensile stress appeared in the middle of two fulcrum location.This is why the crack usually occurs on midperpendicular of two fulcrum in three impact test,and extended from the lower to the upper edge along the bottom edge in three points impactstests;charpy internal stress model gradually translated to the static equilibrium state of ＂ pull the pressure ＂,with further balance of the dynamic stress waves in the internal model.