ESPI Pattern Image Process

The welding is a localized heating, melting and coagulation process. In this process, the welding results serious remaining stress and the distortion, affects the welding structure size precision, reduces the size stability, even also results serious influence welding structure bearing capacity. So, we must control the welding process and produce the stress and distortion. It is important to understand and grasp the rule of the welding dynamic bias field change in the entire process. So we can finally propose effective method to control the welding remaining stress and the distortion. But the welding dynamic bias field characteristic is high temperature and high speed distortion, the ordinary strain gauge cannot withstand the so high temperature, and grain law can withstand only 800℃by cutting the grating, so it was not able to use to survey the welding heat-affected zone to high temperature area dynamic bias field. Therefore, this article changed the vision the non- contact type to disperse the spot interference measuring technique. The electron disperses the spot interference to measure the mensuration (ESPI) is one kind of modern optical measurement technology, with method and compare with the traditional resistance strain gauge survey, can grain survey compares, it has the non- contact type, the anti- mixed light disturbance, the measuring accuracy is high, the surface does not need merit and special handling, not damages by the widespread application to optics scored surface distortion survey the examination. This article in view of the welding process dynamic bias field ESPI survey, studied the effective processing method of dispersed spot interference fringe picture.This article uses the double light beam law to test in the surface which the aluminum alloy board being heated distortion produces the bias field. The double light beam law is two bunches of coherent light separately from the board normal two sides...