毕业论文：《焊接接头的静载拉伸进行模拟及其MSC.Marc有限元计算》.docVIP

PAGE II - - 摘 要 随着焊接技术广泛应用于各种工程结构，它给低合金高强钢的应用与发展带来了深远的影响，有关低合金高强钢焊接接头的匹配问题得到了较为深入的研究。传统的焊接工艺多采用匹配比较高的焊接方法，虽能保证焊缝具有一定的静载承载能力，但高强匹配接头易引发冷裂纹，加之热影响区韧性恶化，易引起低韧性脆断。所以目前大多采用低强匹配接头，而低强匹配接头的匹配比选定就成为主要问题。本文以低匹配的低合金高强钢的匹配比选择入手，考虑在低强匹配前提条件下，探讨匹配比对低合金高强钢焊接接头承载能力的影响。 实验前期应用大型有限元分析软件MSC.Marc进行有限元计算，对焊接接头的静载拉伸进行模拟，指导实验所需的低匹配焊接接头的最终成型。实验过程中，根据国家标准的拉伸实验方法选取3种接头试件进行研究分别为等强匹配的自然接头、低匹配的自然接头和低匹配优化的对接接头进行拉伸实验测试。 最后通过对实验结果的分析，得到相应的实验数据。在的实验中可以得到普通接头的匹配比不能过低，否则承载能力明显降低，匹配比应限制在一定的范围内；而通过接头形状设计，完全可以使高强钢的低强匹配接头能够在较大范围选择匹配比而不必降低应用应力。 关键词 高强钢；焊接接头；应用应力；匹配比 Abstract With welding technique is widely used in various engineering structures, HLSA steel to the application and development of a far-reaching impact on the high strength low alloy steel welded joints matching problem has been more indepth study.The traditional use of welding technology matching relatively high welding, weld has been able to guarantee a certain static load carrying capacity, but highs-trength joints easily trigger matching cold-crack, In addition HAZ toughness deterioration caused low-brittle fracture toughness. So most of the current low-mat-chiing joints, and low-matching connector on the selected match than a major pr-oblem. In this paper, a low matching high strength low alloy steel than selecting the start of the match, considering the premise of low-matching conditions, the ratio of matching high-strength low-alloy steel welded joints capacity impact. Before the experiment, we use the limitedelement method software-MSC.M arc to analyze the drawing capacity of the butt joint, then give the foundation of designing the shape of the butt joint, supervising producing the needed joint in the experiment. According to the method of drawing experiment of national criterion, we choose 3 kinds of joints: normal joint, normal mis-matched butt joint and optimized mis-matched butt joint, then have experiments to these joints. After getting the experimental data, we analyze these data, Low-matching to explore joint matching ra