Studies on Thermal Elastic-Plastic Problems (2 nd Report)
Studies on Thermal Elastic-Plastic Problems (2 nd Report)
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热弹塑性问题研究（第二次报告）
DOI：
10.2534/jjasnaoe1968.1976.140_248
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发表时间：
1971
期刊：
影响因子：
--
通讯作者：
K. Satoh
中科院分区：
文献类型：
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作者：
Y. Fujita;T. Nomoto;K. Satoh
众所周知，钢结构在焊接或切割过程中会产生瞬态热应力和应变，这些残余应力与氢的扩散和结构的约束刚度相结合，可能是产生冷裂纹的原因之一。本文介绍了一种新的焊接残余应力和应变计算技术。 一维问题的热弹塑性应力分析已经研究了很多年。在上一篇论文中，作者报道了基于位移法的有限元技术的公式，该技术可应用于二维或三维热弹塑性应力问题。近年来，由于计算机应用的显着进步，使用有限元技术等强大的数值方法可以解决更加复杂和现实的问题。相反，作者提出了一种新的计算方法，该方法将整个区域划分为F.E.M.等有限元的思想与藤本引入的修正初始应变法和应力函数相结合。上述应力函数与Kawai研究的影响函数的概念相对应，由于这种影响方法是应力方法的一种，所以很容易理解，这种新方法计算的结果与实验数据具有相当的吻合性。证实了，当需要更精确的应力分布时，基于固有应变法的热弹塑性应力分析与位移型有限元方法相比是相当有效的，而且当需要多次增量重复时，计算时间会大大减少。
It is well known that during welding or cutting, transient thermal stresses and strains are produced in steel structures and these residual stresses could be one of the causes of cold cracking in cooporation with diffusion of hydrogen and restraint rigidity of the structures. In this paper, a new calculation technique of residual stresses and strains due to welding is described.Thermal elastic-plastic stress analysis for one-dimensional problems has been studied for many years. In the previous paper, the authors reported the formulation of the finite element technique based on displacement method which could be applied to two or three dimensional thermal elastic-plastic stress problems. Recently, more complicated and realistic problems could be solved by using powerful numerical methods such as finite element technique, etc., because of the remarkable progress in computer application.On the contrary, the authors present a new calculation method which combines the idea of dividing the whole region into finite elements such as F. E. M. with the modified initial strain method and stress function introduced by Fujimoto. The above-mentioned stress function corresponds to the concept of the influence function studied by Kawai, and since this influence method is a sort of stress method, it is easily understood that the results calculated by this new method could show fair coincidence with the experimental data.It is comfirmed that thermal elastic-plastic stress analysis based on inherent strain method is rather effective compared with the finite element method of displacement type, when more accurate stress distribution is required, and also that calculation time would be much less when many incremental repetitions are needed.