弯扭组合变形实验的改进与探讨

Improvement and Discussion of Combined Deformation Experiment of Bending and Torsion

为了提高弯扭组合变形实验装置的应力测量精度,采用3个单片层叠的应变花改进了原有实验装置,实现了同一测点沿不同方向上的应变测量。应用上述改进装置开展了实验测试。结果表明,该改进装置能有效减小主应力、泊松比、扭转切应力和弯曲切应力的测量误差(前三者误差都在3%以内),提高了基于电测技术的力学参数测量精度。

In order to improve the stress measurement accuracy of combined deformation experimental device of bending and torsion,the original experimental device is improved by using strain rosettes composed of three laminated strain gauges,achieving strain measurement in different directions at the same measuring point.Based on the above improved device,experimental tests are carried out.The experimental results show that the improved device can effectively reduce the measurement errors of principal stress,Poisson's ratio,torsional shear stress and bending shear stress(the errors of the first three are within 3%),thus improving the measurement accuracy of mechanical parameters based on electrical measurement techniques.