摘要
材料条纹常数是光弹性实验的一个关键参数,也是联系力学量和光学量的纽带,要求具有较高的标定精度。在线性最小二乘法的基础上,该文提出一种自动化确定光弹性材料条纹常数和对径压缩圆盘中心位置的方法。使用相移光弹性法得到对径压缩圆盘全场等色线级数作为实验数据,利用最小二乘法建立超定非线性方程组,最后通过牛顿迭代法求解来自动确定光弹性材料条纹常数和圆盘中心位置,并进行了实验验证。
A nonlinear least-squares method was applied to determine the photoelastic fringe constant from isochromatie phase field obtained by digital phase-shifting photoelasticity. To perform automatic evaluation, the photoelastic fringe constant and the center coordinates of a disk under diametral compression are determinated simultaneously using the nonlinear least-squares method. A set of over-determinated nonlinear equations are obtained to estimate the unknown parameters by an iterative procedure based on Newton-Raphson method. Experimental result shows that the parameters are evaluated accurately from the isochromatic phase field obtained from the six-step phase-shifting photoelasticity. The photoelastic fringe constant and the disc center coordinates can be evaluated easily, simply and automatically by the technique.
出处
《工程力学》
EI
CSCD
北大核心
2009年第12期40-45,51,共7页
Engineering Mechanics
基金
国家自然科学基金项目(10502014
50704009)
工业装备结构分析重点实验室项目(S08206)
关键词
光弹性材料条纹常数
最小二乘法
牛顿迭代法
超定非线性方程组
数字光弹性
photoelastic material fringe constant
least-squares method
Newton-Raphson method
over-determinuted nonlinear equations
digital photoelasticity
