On stability of a new side cut destructive method for measuring non-uniform residual stress in thin plates
On stability of a new side cut destructive method for measuring non-uniform residual stress in thin plates
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DOI：
10.1016/j.ijsolstr.2016.08.019
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发表时间：
2016-12
影响因子：
3.6
通讯作者：
H. K. Kim;A. Shterenlikht;M. Pavier;A. Velichko;N. Alexander
中科院分区：
文献类型：
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作者：
H. K. Kim;A. Shterenlikht;M. Pavier;A. Velichko;N. Alexander
介绍了最近提出的用于薄板残余应力测量的机械应变松弛方法的稳定性和灵敏度分析。该方法基于具有自平衡端部载荷的半无限弹性条的 Mathieu 级数解。分析了试件长度、不完整的位移数据和刚体旋转误差的影响。该分析结果用于改进 3 mm 厚的 5083-O 合金搅拌摩擦焊接板残余应力测量方法的性能。使用放电加工 (EDM) 线进行贯穿切割。 3D 数字图像相关用于测量松弛位移。重建的残余应力分布与能量色散 X 射线衍射 (EDXRD) 测量的残余应力分布一致。结果表明，EDM 线相对于板材的方向显着影响切割引起的塑性应变。当 EDM 切割穿过板的厚度时，即当板宽度方向平行于 EDM 线时，该应变最小化。 EDM 线的这种取向导致切割表面上的诱导塑性最小。这是该方法的主要优点，这使得它在其他机械应力松弛方法在切割时遭受塑性流动的实际应用中具有吸引力。
Stability and sensitivity analyses of a recently proposed mechanical strain relaxation method for residual stress measurement in thin plates are presented. The method is based on the Mathieu series solution for a semi-infinite elastic strip with self-equilibrated end loading. The effects of the specimen length, incomplete displacement data and rigid body rotation errors were analysed. The results of this analysis were applied to improve the performance of the method for the measurement of the residual stress in a 3 mm thick friction stir welded plate of Aluminium 5083-O alloy. A through cut was introduced with an electrical discharge machining (EDM) wire. 3D digital image correlation was used to measure the relaxation displacements. The reconstructed residual stress profile agrees with that measured by energy dispersive X-ray diffraction (EDXRD). It is shown that the orientation of the EDM wire with respect to the plate significantly affects cutting induced plastic strain. This strain is minimised when the EDM cut is through the thickness of the plate, i.e. when the plate width direction is parallel to the EDM wire. Such orientation of the EDM wire leads to a minimal induced-plasticity on the cut surface. This is a major strength of the method, which makes it attractive in practical applications where other mechanical stress relaxation methods suffer from plastic flow on cutting.