用三单元法确定三维光弹模型逐点的应力张量

用光弹性方法分析复杂工程结构内部应力时,一般需要三个平行切片,或者将切片切子片进行观测。三单元法作出解答时只需要一个切片,将一个切片平行分成三个单元,利用光学等效原理和实验确定的特征参数,能够定出三维光弹模型沿切片厚度方向的剪应力变化的斜率,进而应用切力差法进行计算。显然,三单元法是平行切片法的发展和进步,该法不仅省工、省时,而且可以提高三维应力分析的精度。

Use Three Element Method to Determine the Stress State of the Points in Three Dimensional Photoelastic Model

In analysing interior stress in complex engineering structure generally three parallel slices are nseded, or the slice should be cut into a subslice.Only one slice is needed by three element method, the slice is devided into three elements. Using the principle of optical equivalence and the experimentally determined characteristic parameters, it is possible to determine the slope of the variation of the secondary principal stresses along the direction of the thickness of slice taken from a three dimensional photoclastic model, and then, the shear difference method can be applied. The three element method is a development of the parallel slice method. It not only can save labor and time but also improve the precision for three dimensional photoel stice stress analysis.