共查询到19条相似文献,搜索用时 281 毫秒
1.
焊接残余应力和变形三维弹塑性有限元模拟由于是高度非线性的热力耦合过程而计算非常耗时.为提高计算效率,采用动态子结构方法来计算焊接残余应力和变形.考虑焊接过程中只有焊缝和热影响区的小部分区域在焊接热源作用下呈现高度非线性,而其余区域受热源的影响小,将整个模型的三维弹塑性计算问题处理为窄小的焊缝和热影响区为局部非线性弹塑性区,其余大部分非焊接区域作弹性子结构的计算问题;且随焊接热源的移动,子结构不断变化.结果表明,动态子结构方法能显著提高计算效率,并能保证焊缝和热影响区的残余应力分布与全模型计算结果接近. 相似文献
2.
3.
4.
5.
以最简单的平板堆焊为分析对象,分别采用ANSYS、ABAQUS以及JWRIAN软件对其焊接过程进行热弹塑性有限元分析,通过改变焊接参数的系列计算,全面分析温度场和应力场的计算结果,并利用获得的热输入量参数与横向收缩及角变形的关系曲线与公开发表的实测数据进行对比,清楚地显示了这几种软件在焊接力学过程热弹塑性有限元分析的差异。 相似文献
6.
基于ABAQUS有限元分析软件,开发了考虑移动热源、材料非线性和几何非线性的热-弹-塑性有限元计算方法.利用所开发的数值方法对薄板单道堆焊时的焊接残余应力和变形进行了模拟.同时采用试验方法测量了薄板接头的焊接变形和残余应力.通过对比数值模拟结果和试验结果,验证了所开发方法的有效性.在同时考虑几何非线性与材料非线性的情况下,有限元计算得到的焊接变形结果与实测值一致;计算得到的焊接残余应力也与实测值比较吻合.此外利用数值模拟方法详细研究了薄板焊接变形的特点和残余应力的分布特征. 相似文献
7.
8.
为了明确插管结构的焊接变形规律,利用有限元分析软件MSC.Marc,考虑材料非线性和几何非线性,建立了热弹塑性有限元模型,应用生死单元法分别模拟了两个插管与壳板的焊接过程.结果表明,插管发生鼓胀变形,并伴有轴线的偏移;焊缝附近的壳板发生翘曲变形,壳板其余位置刚度较小处发生较大的下塌变形.在插管结构的有限元模拟之前,通过平板对接试验与相应模型的有限元模拟对比,从特征节点的热过程、特征节点的焊接残余应力和焊后角变形三个方面论证了有限元模型及相关输入参数的合理性. 相似文献
9.
10.
基于焊接热弹塑性有限元分析理论,采用焊接专用有限元分析软件对不同焊接顺序的汽车用S355J2G3钢工字梁焊接结构手工MAG焊接过程进行了数值仿真,获得不同焊接顺序下焊接结构的变形和残余应力分布.模拟时,选择双椭球焊接热源模型,考虑了材料热物理性能与温度的非线性关系,以及相变潜热对温度场的影响.重点研究了焊缝及临近焊缝区域焊接残余应力和变形的分布特征,并进行了理论分析. 相似文献
11.
焊接温度场和应力场的热弹塑性有限元分析 总被引:10,自引:0,他引:10
针对低碳钢薄板件TIG对接焊工艺 ,应用双椭圆分布热源模型 ,建立了TIG对接焊三维温度场有限元数值分析模型 ,将温度场有限元解同实验结果进行了比较 ,两者吻合较好。在此基础上 ,考虑材料非线性并采用热弹塑性有限元方法 ,得到了不同时刻热应力场的演化过程 ,为焊接残余应力和变形的研究打下了基础。 相似文献
12.
SYSWELD was used to simulate in-service welding process of gas pipeline of X70 pipeline steel. Welding thermal cycle, stress and deformation of in-service welded joint were studied. The results show that peak temperature of coarse grain heat-affected zone (CGHAZ) of in-service welding onto gas pipeline is the same with routine welding, but ts/5, ts/3 and ts/1 decrease at certain degree. For the zone near welded seam, axial stress and hoop stress in the inner pipe wall are compressive stress when welding source passes through the cross-section that is studied, but residual axial stress and residual hoop stress after welded are all tensile stress. Transient deformation and residual deformation are all convex deformation compared with the original pipe diameter size. Deformation achieves maximum when welding thermal source passes through the cross-section that is studied and then decreases during the cooling process after welding. 相似文献
13.
1.lhtroductionBecauseaweldmentislocallyheatedbytheweldingheatsource,itstemperaturefieldisextremelynon--deformspatiallyandtime--depended.Thereforethestrainandstressareverycomplexinweldingprocess,WhichincreasetheweldingdefectsandhaveimportanteffectontheqUalityofweldingstmctures.Correctingunacceptablewelddistortionaswellasdecreasingweldingresidualstressisverycosily,andinsomecasesimpossible.SothedevelopmentofpropertechniqUesforreducingandcontrollingdistortionorweldingresidualstresswouldleadtomore… 相似文献
14.
针对典型飞机焊接构件,研制焊接热过程、应力应变以及变形的模拟系统.提出并利用面向网格划分的数据抽象造型方法,实现模拟过程的自动化.解决一般有限元软件模拟飞机构件焊接温度场和应力/应变场过程中操作繁琐的问题.系统采用面向对象方法设计.利用文中系统,用户只需输入构件模型几何参数,网格尺寸、热源参数、装夹位置和焊接顺序.这些参数经过系统核心类计算,生成温度和应力/应变模拟的自动化信息.自动化信息由系统转化为Marc的命令流文件,自动被导入到后台运行的Marc中计算,并对结果分析,实现对典型飞机构件焊接温度、应力/应变以及变形预测和分析. 相似文献
15.
采用Abaqus有限元计算软件,对摩擦螺柱焊的焊接过程进行了仿真研究.通过在Abaqus/stand算法的基础上利用Python脚本编程实现了参数化建模、网格自动重划分以及结果映射、散热边界自动选取等功能,有效解决了焊接过程中由于材料大规模非线性塑性变形导致的计算收敛困难问题.仿真计算获得的螺柱塑性变形情况与实际焊接结果基本一致,有效证明了该有限元模型的合理性.另外,通过对焊接温度场及应力场结果的分析,较好的解释了干式环境和有水环境下采用相同焊接工艺参数的焊接接头质量存在差异的现象,这对摩擦螺柱焊技术的水下应用及其工艺参数研究具有重要的指导意义. 相似文献
16.
Four different welding sequences of double-pulse MIG welding were conducted for 6061-T6 aluminum alloy automobile bumpers by using nonlinear elastoplasticity finite element method based on ABAQUS software. The post-welding residual stress and deformation were definitely different among the four welding sequences. The results showed that the highest temperature in Solution A was approximately 200 °C higher than the melting point of base metal. High residual stress was resulted from this large temperature gradient and mainly concentrated on the welding vicinity between beam and crash box. The welding deformation primarily occurred in both of the contraction of two-ends of the beam and the self-contraction of crash box. Compared with other welding sequences, the residual stress in Solution A was the smallest, whereas the welding deformation was the largest. However, the optimal sequence was Solution B because of the effective reduction of residual stress and good assembly requirements. 相似文献
17.
应用一维杆模型论证了随焊加载冷源或位移控制载荷实现无应力焊接的原理. 应用数值模拟探讨了其实现方式,对7种加载方案下杆件中心点应力、塑性应变等物理量的时程分布进行了数值模拟对比研究,认为任意时刻外加位移控制载荷产生的机械应变和热输入满足一定条件时焊后残余应力为零. 随焊降低残余应力的工艺在焊件局部区域产生的变形速率与该局部区域的热膨胀或收缩变形量速率大小相同时,降低残余应力的效果达到最优. 应用模型导出的原理对焊前预拉伸、焊前温差拉伸、动态温差拉伸、低应力无变形焊接(LSND)等工艺的原理和参数设置依据进行了讨论. 结果表明,使焊件内部在冷却时产生足够大的拉伸塑性应变,是降低焊接残余应力的有效途径. 相似文献
18.
The new technology of welding with impacting rotation is put forward to decrease the wave-like deformation of the TC4 thin plate weldment.The thermal stress and strain are vital to understand the mechanism of controlling the wave-like deformation.In order to know the development of internal thermal stress and strain,finite element method is utilized for the stress and strain are difficult to be investigated by experimental methods during the welding process.Temperature field,thermal stress evolution and distortion of thin plate are compared with the test results such as weld thermal cycle,residual stress sectioning measurement,and the deflection of the thin plate respectively.By the finite element analysis and test results verification,the mechanism of the technology to control the wave-like deformation is brought forward,non-uniform thermal elastic strain between compressive plastic region and elastic extensive region is diminished by a certain amount of extensive plastic deformation by welding with impacting rotation process. 相似文献
19.
在超薄金属板焊接过程中,残余应力及变形对产品质量有重要影响.文中研究了316不锈钢超薄板(厚度为70 μm)脉冲激光焊接过程的残余应力和焊接变形.采用热-弹-塑性有限元法和半椭球移动热源模型,考虑模型的几何和材料非线性因素,采用顺序耦合的方法对超薄板结构的温度场、应力-应变场进行模拟.采用光纤激光器对70 μm的316不锈钢板进行焊接,用红外测温仪对特征点热循环进行测量,用激光位移传感器测量了焊接变形,用X射线衍射应力测试仪测试了残余应力.结果表明,温度场、残余应力、变形的模拟计算结果与试验结果吻合. 相似文献