激光穿透焊T型接头热点应力计算方法研究.pdf

激光穿透焊T 型接头热点应力计算方法研究 邹聪，罗广恩 (江苏科技大学 船舶与海洋工程学院 ，江苏 镇江 212003) 摘要：由于海洋环境载荷的交变特性，船舶结构最重要的损坏形式之一就是疲劳失效。金属折叠式夹层板 作为新型船舶结构，具有广阔的应用前景，研究其疲劳性能对于提高船舶与海洋结构物的强度具有重要意 义。热点应力法作为焊接结构疲劳强度评定方法，在激光穿透焊接接头的疲劳评定中鲜有应用，而且在热 点应力法中，有限元分析起到至关重要的作用。本文首先介绍了热点应力的定义、热点应力类型、热点应 力外推方法等热点应力基本理论，然后以U- Ⅱ型金属折叠式夹层板中激光穿透焊 T 型接头为研究对象，以 热点应力基本理论为基础，利用数值仿真软件 ANSYS 计算得到各模型节点应力，比较分析了不同单元类 型、单元尺寸以及外推方法对热点应力计算结果的影响。研究表明：单元划分需考虑单元类型的影响，单 元尺寸对热点应力有较大影响，而外推方法对热点应力影响相对较小，板厚方向至少需划分 3 层单元。 关键词：船舶结构；激光穿透焊T 型接头；热点应力；疲劳评定；有限元分析 Research on hot spot stress calculation method of laser penetration welded T-joint ZOU cong, LUO Guang-en (School of Naval Architecture and Ocean Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu) Abstract ：Due to alternating characteristic of marine environmental loads, one of the most important forms of damage of ship structure is fatigue failure. As a new type of ship structure, steel folded sandwich panel has wide application prospect, the research on its fatigue performance is significance to improving the strength of ships and marine structures. Hot spot stress method is used as the fatigue strength assessment methods of welded structures, rarely applied in fatigue assessment of laser penetration welded joints, also in the hot spot stress method, finite element analysis plays an important role. Firstly The paper introduces the definition, the type, the extrapolation method of hot spot stress and some theories, and then taking laser penetration welded T-joint from U- Ⅱtype sandwich panel as the research object, taking hot spot stress theories as the foundation, the node stress of each model is calculated by numerical simulation software ANSYS,the effects of different element type, element size and extrapolation method on calculation results of hot spot stress