中文摘要：

测试并控制焊接接头局部强度,对改善焊接工艺、提高接头整体性能非常必要.提出一种双孔微剪切方法,以无损或低破坏待测体为前提,在被测材料区域两侧钻2个直径为6mm的孔,进行剪切试验.通过测试系统中的LabvIEW软件控制部分,输入加载过程中载荷传感器和位移传感器的传输信号,输出反映材料变形性能的加载响应曲线,通过转化获得屈服剪切应力和最大剪切应力.建立双孔微剪切试验的有限元模型,选择不同屈服应力和加工硬化指数的材料进行有限元模拟,拟合得到试验剪应力-应变曲线与材料强度参数的相关性,获得了材料强度的参数.并利用双孔微剪切试验,测定430铁素体不锈钢焊接接头上各微区的强度.

英文摘要：

The test and control of local strength of welded joint is necessary to improve the welding process and overall performance of the joint.A double-hole micro-shear method is tentatively presented,in which,taking no-damage or low-damage with the tested body as premise,two holes with diameter of 6mm are drilled at both sides of tested region of the material and the shearing test is conducted.The loading signals transmitted with load and displacement transducers are input and the loading response curve which reflects the deformation performance of the material is obtained through the controlling part of labvIEW software in the test system,so that the yield shear stress and maximum shear stress are obtained by means of transfer.A finite element model of double-hole micro-shear test is established and finite element simulation is carried out for the materials with various optional combination of yield stress and work-hardening exponent,so that the correlativity of material strength parameters to experimental curves is obtained by means of fitting.The obtaining of material strength parameters is realized with double-hole micro-shear test.The micro-regional strength of welded joint of 430 ferritic stainless steel is determined by using double-hole micro-shear test,also.