提出了一种基于二次曝光数字全息干涉术的子午线轮胎内部气泡缺陷无损检测方法。该方法利用数字全息记录系统记录下轮胎初始状态和受热膨胀变形状态的数字全息图,在计算机中对这些数字全息图分别再现后,将代表轮胎变形状态的再现波前与其初始状态的再现波前进行干涉,获得携带轮胎变化信息的干涉条纹和相位分布;分析了存在气泡缺陷区域的轮胎和无缺陷轮胎两种情况下的干涉条纹及其相位分布的特点和区别。分析结果表明:在轮胎内部存在缺陷的位置,其二次曝光数字全息干涉条纹具有与质量正常位置处干涉条纹相对独立的特征,该方法可以检测出轮胎气泡缺陷,记录系统的横向分辨率为16.4 μm。

A double-exposure digital holographic interferometry is proposed to use in the inspection of the air bubble defect in radial tires. A series of digital holograms recording the initial state and deformation state of a radial tire are recorded in a computer,then the reconstructed images are obtained by the computer. In comparison with the interference fringes between the deformed wave-front and undeformed wave-front from the defective tires and the regular tires,the characteristics of the interference fringes and phase distribution from different tires are obtained and the detection rules are established. The results show that the double-exposure digital holographic interference fringes in the air bubble defect area have special features,which indicates the proposed method can be used in tire defect inspection in high precision,and the horizontal resolution of the system is 16.4 μm.