Computer Aided Nondestructive Evaluation Method of Welding Residual Stresses by Removing Reinforcement of Weld. A Proposal of New Concept and Its Application to Butt Welded Plate.
Computer Aided Nondestructive Evaluation Method of Welding Residual Stresses by Removing Reinforcement of Weld. A Proposal of New Concept and Its Application to Butt Welded Plate.
复制标题
去除焊缝强化焊缝残余应力的计算机辅助无损评价方法。
DOI：
10.1299/kikaia.65.133
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Hideo Kobayashi
中科院分区：
文献类型：
--
作者：
K. Kumagai;Haruo Nakamura;Hideo Kobayashi
在前人工作的基础上，提出了焊接结构应力无损检测系统的新概念。首先，去除焊缝的钢筋。从表面上的应变变化，由于删除，本征应变的分布确定的反分析。然后，残余应力估计的弹性有限元（有限元法）分析，使用确定的本征应变分布作为初始条件。为了实现这一概念，该方法的适用性进行了检查，通过模拟对接板的各向异性特征应变沿着和焊缝附近。初步分析了各本征应变分量对焊接残余应力的影响，发现焊道方向的本征应变分量对产生垂直于焊缝和平行于焊缝的残余应力有显著影响。因此，通过将该主导分量与其他两个分量分离，可以显著提高逆分析的精度。进一步尝试减少未知参数的反分析是近似本征应变分布，通过使用一系列的逻辑函数，这被证明有广泛的适用性作为曲线拟合函数形式的实际本征应变分布在各种焊接条件下。最后，它表明，焊接残余应力沿着和垂直于焊缝在任何位置的板可以使用所提出的方法来评估。
Based on previous works, a new concept of a nondestructive stress measuring system for welded structures was proposed. Firstly, reinforcement of weld is removed. From strain changes on the surface due to removal, distributions of eigenstrain are determined by the inverse analysis. Then, residual stresses are estimated by the elastic FEM (Finite Element Method) analysis by using the determined eigenstrain distributions as anihnitial condition. Toward realization of this concept, applicability of this method was examined by simulations for a butt welded plate with anisotropic eigenstrains along and near a welding line. In a preliminary analysis on an effect of each eigenstrain component on welding residual stresses, it was found that an eigenstrain component in bead direction has a significant influence on producing residual stresses perpendicular and parallel to the welding line. Thus, by separating this dominating component from other two, an accuracy in the inverse analysis can be considerably improved. Further attempt to reduce unknown parameters in the inverse analysis was to approximate eigenstrain distributions by using a series of logistic functions, which proved to have a wide applicability as a curve fitting function form to actual eigenstrain distributions under various welding conditions. Finally, it was shown that welding residual stresses along and perpendicular to welding line in any location of the plate can be evaluated by using the proposed method.