光弹性应力自动分析

Automated Photoelasticity Stress Analysis

采用相移技术,实现光弹性等差线和等倾线参数的全自动判读,从而实现模型内部应力的全自动化分析。首先,在正交平面偏振光场下获得4幅等倾线图像,经相移技术处理后得到主应力方向的位相图,利用主应力迹线跟踪方法,可全场获得第一主应力方向;然后,借鉴Tardy补偿法,沿8个离散方向对等差线进行相移,并通过第一主应力方位角合成等差线全场的位相图像,经去包裹处理后得到全场主应力差的参数;最后,基于以上参数,用剪应力差法进行应力的计算,给出对径受压圆盘实例来说明该方法的实用性。结果表明,此光弹性应力自动分析技术能准确、快速地分析光弹性应力,突破了传统光弹性数据处理周期长的瓶颈。

Phase shift is applied to calculate parameters are determined with shear stress differential methods. from photoelastic fringe patterns. Stress components In planar polariscope, four fringe patterns with specific angles are acquired and the phase map of the orientation of principal stresses derived from isoelinies according to four-step phase stepping. A method is proposed to determine orientation of the first principal stress in the entire field. Similar to Tardy compensation, isochromatic fringe patterns are analyzed in 8 discrete directions. In each direction, phase shift is achieved by rotating the analyzer in the circularly polarized field. With information of the orientation of the first principal stress, the phase map of isoehromaties for the entire field is constructed from the 8 phase maps. Thus, stress eomponents within the photoelastic model can be determined. An example is given to illustrate the merits of the proposed methods.