【作者】 傅卫；

【导师】 方洪渊；

【作者基本信息】 哈尔滨工业大学 ， 材料加工工程， 2006， 硕士

【摘要】 随着计算机技术的发展,有限元数值模拟已经被广泛地应用到焊接领域的理论研究和实际应用中,越来越多的企业开始关注数值模拟工作,并希望利用数值模拟技术解决实际生产问题。但是,目前的有限元计算软件一般都是从欧美等西方发达国家引进,为通用软件,并不是针对特定领域设计,且操作极其复杂,加上全英文界面,从而限制了数值模拟技术在企业中的广泛应用。本文针对这一现状开发了一个专门针对焊接过程数值模拟的有限元前处理系统,并应用该系统建立了某型号导弹油箱结构的焊接有限元模型,分析了该结构的焊后变形规律。该前处理系统界面简洁明了,操作简单方便,用户按照该系统界面进行操作即可完成模型网格划分、材料性能参数的输入、热源模型选择及焊接参数的输入、以及初始条件和边界条件的设置添加,为模拟计算做好准备,从而使工厂的一般技术人员也能完成焊接过程的模拟计算。对于某型号导弹油箱结构焊接过程的数值模拟计算,主要考察了每块立板上各段焊缝焊接顺序的调整、四块立板之间不同的焊接顺序以及焊接起始端的选择对结构焊后变形的影响规律,模拟结果表明:壁板在各种焊接顺序下的整体变形规律基本相似,即焊后壁板沿焊缝纵向发生了向下的挠曲变形,中部向下变形量最大;沿焊缝横向发生了向上的挠曲变形,壁板两端部变形量较大,且壁板前端变形大于壁板后端。各种焊接顺序下的壁板变形相差不大,但对于单块立板而言,先点固两端然后交错对称焊接;在整体结构焊接过程中,对四块立板依次焊接相同位置的焊缝,此时壁板焊后变形最小。焊接起始端的选择对壁板焊后变形影响不大。盖板结构焊后基本未产生焊接变形。采用设计的焊接顺序在导弹油箱壁板实际结构上进行焊接并对焊后壁板变形进行了测量,测量所得的壁板变形规律与模拟计算结果吻合良好。更多还原

【Abstract】 As a result of high speed evolution in computer science, the applications of Finite Element Method (FEM) were developed in theoretical and practical researches of welding, which got more and more attentions from numerous enterprises. The final goal of these researches was using FEM to solve the problems in the manufacture and production. However, some things limited the development of FEM technology in China. For example, most of the simulation software was from the developed countries like Europe and America, and this software was not easy to operate with a complex interface in English and not specialization in the particular research field or special purpose. To solve these problems, a FEM preprocessing system in materials joining process has been developed in this dissertation. Based on this system, a welding numerical model of a missile’s oil box has been established and the structure’s distortion rules after welding have been analyzed.The control panel of this preprocessing system is simple and convenient. The friendly interface between computer and human allows the users easy to complete all the preprocessing operations, including the model’s meshing, the setup of the material parameter and welding processing parameter, the initial conditions and boundary conditions’definition etc, preparing for the simulation subsequently. So any operator with lack of knowledge in FEM or English can finish the welding simulation during using this preprocessing system.As an application of this FEM preprocessing system, the simulation on the welding process of missile’s oil box was performed, in which the effects of the welding sequences of four web plates and welds on each web plate are primarily analyzed. The simulation results show that the deformations under varied welding sequences are almost the same. Downward deflection deformation is obtained along the weld longitudinal direction in the structure as well as upward deflection deformation along the weld traverse direction. The welding start location has little effect on the deformation of the structure. The minimal deformation of the structure is obtained using the method presented as follows: four web plates are first tack welded on both ends, and then the web plates are更多还原