数字光弹性相移法中全场等倾角和等差线相位

以径向受压圆盘为例,从弹性力学的角度详细分析了模型全场等倾角相位的情况,分析第一主应力的方向,在六步相移法的基础上提炼出圆盘全场等倾角相位和等差线的真实相位。采用有限元软件MARC与形函数拟合相结合的方法模拟径向受压圆环六步相移图和等差线相位图,可以推广到没有解析解或者解析解复杂的应力模型的光弹性实验模拟。通过径向受压圆盘实验验证了方法的可行性,实现光弹法中自动提取全场等差线的信息。

Whole-Field Phase of Isochromatic Angle and Isoelinic Line in Digital Photoelastic Phase-Shifting Technique

Taking the disk under diametral compression as an example,the whole-field isoclinic-angle phase of the model was analyzed according to elastic mechanics,and the principal-stress direction was put forward.Base on six-step phase shifting technique,the actual phase of whole-field isoclinic angle and whole-field isochromatic of a disk was extracted.Combining finite element software MARC with fitting of shape function,six-step phase shifting and isochromatic phase patterns of a ring under diametral compression were simulated.This method can be generalized to simulate the photoelastic experiment of stress model with complex analytic solution or without analytic solution.The feasibility of this method was proved by the experiments of a disk under diametral compression,and the information of whole-field isochromatic could be extracted automatically.