焊接接头裂纹尖端应变场的云纹干涉法

Investigation on Crack Tip Strain Field of Welded Joint by Moire Interferometry

关键词:  接头  云纹干涉  位移场  应变场  裂纹

Key words:  welded joint  moire interferometry  displacement field  strain field  crack

摘要:

以海洋平台用钢A537采用LB52NS焊条施焊的高匹配中心裂纹试件为例,本文引入一种新的光力学方法——反射式贴片云纹干涉法及其剪切技术,对该方法的基本原理与试验技术进行了系统论述,并结合小型宽板拉伸试验成功地应用于接头裂纹尖端应变场的测试。由于该方法有高灵敏度(虚栅频率≥600L/mm)和极宽的可调量程,对横向应变场的测试更为有利。

Abstract:

A new photo-mechanics method named Moire interferometry of reflected sticking film and its shearing technique are introduced in this paper. The basic principle and its technique are stated also. As an example, the crack tip strain field is measured for an overmetching-weld tension specimen with centre crack of A 537 steel used for offshore platform welded by LB52NS electrode. Because of its high sensityvity(virtual grating frequency is 750lmm) and wide variable measurement scale, the method is more useful for the measurement of honrizontal strain field.