光弹性颗粒的线扫描测力方法

Linear scanning force measurement method based on photoelastic particles

提出了基于对光弹颗粒的应力光图进行加载点至圆心的线扫描以测接触力大小的办法.在正交圆偏振光场中获取了光弹颗粒的应力光图的等差条纹图案后,通过数字图像的处理,获取颗粒模型边界,得到颗粒圆心,半径等信息.并从应力光图的平方灰度梯度分布图出发,提出一种能够自动检测颗粒的接触点位置信息的方法.由多点加载的二维圆盘颗粒的光弹性原理,结合接触点位置信息,在力范围内,模拟得到每一种的接触力情况的每一加载点至圆心连线上光强灰度变化.将其与实验光强结果对比,可反推出颗粒接触力的大小.

The method of measuring contact force by line scanning from the loading point to the center of the circle based on the stress light diagram of photoelastic particles was presented.The boundary,center and radius of the model particle were obtained through digital image processing,after obtaining the isochromatic fringe pattern of the stress-optic pattern of the photoelastic particles in the orthogonal circularly polarized light field.A method to automatically detect the contact point information of particles was proposed based on the square gray gradient distribution map of stress-optic pattern.Within the scope of the force,combining contact point location information,the change of light intensity from loading point to the center of the circle in every case of contact force was simulated using photoelastic theory of two-dimensional disk particles with multi-point loading.And the particle contact force was found by comparing this with experimental stress-optic pattern.