共查询到17条相似文献,搜索用时 78 毫秒
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采用轴对称和三维模型对镀环激光束焊接过程的温度场和应力场进行了有限元分析,表明2种模型分析结果的趋势基本一致,轴对称模型可以得到焊接准稳态时的温度场和应力场分布,三维模型可以得到整个移动焊接过程的温度场和应力场分布,焊接起弧和收弧部位的残余应力比准稳态时约高20%。 相似文献
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连铸结晶器温度场和应力场的有限元分析 总被引:1,自引:0,他引:1
在高效连铸过程中,结晶器的传热效率起着至关重要的作用。根据小方坯结晶器的传热特点,利用六面体八节点单元,建立了三维非稳态有限元传热数学模型,并用FORTRAN开发了相应的程序,对小方坯结晶器在浇注过程中的温度进行了模拟,获得结晶器温度场分布及变化情况;同时建立结晶器相应的三维应力模型,利用小方坯结晶器温度场的计算结果,模拟了不同结晶器铜板厚度的应力和铜板的变形。结果表明,结晶器壁越薄,变形越严重,应力越大;多锥度结晶器更适合结晶器的变形特点。 相似文献
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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
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电子束焊接过程温度应力场三维有限元仿真 总被引:1,自引:0,他引:1
利用MSC.MARC有限元分析软件,在考虑电子束焊接匙孔效应基础上,采用双椭圆热模型,通过增大热传导系数、降低弹性模量和屈服强度的方法来模拟焊接过程中流体的流动效应,并采用自编子程序模拟了热源移动的过程,给出了铝锂合金电子束焊接过程中的温度应力场分布。计算结果表明:铝锂合金电子束焊接时,电子束热源对焊缝热冲击较大,焊缝附近处最高温度可达1300℃左右,三维方向上存在巨大温度梯度,成为热应力集中产生的根源。同时分析了焊缝不同位置处的等效应力演化过程,发现焊缝初始端应力剧烈振荡,处于复杂的三维应力状态,且自始至终高于焊缝的其他位置处的应力分布,成为接头区域薄弱环节。 相似文献
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针对航空飞机上应用的具有管板接头结构的散热器,利用ANSYS软件,建立二维模型,对1Cr18Ni9Ti不锈钢散热器分别按"直接加热"和"分阶段加热"两种电子束钎焊工艺钎焊的温度场和应力场进行了有限元分析。结果表明,采用分阶段加热钎焊工艺时,获得了均匀的钎焊面温度分布,钎焊面大部分区域的温度在1042~1051℃之间,且在钎焊温度范围之内;对于径向残余应力,采用直接加热钎焊时,钎焊面上出现明显的应力集中区域,而采用分阶段加热钎焊,钎焊面上没有应力集中区出现;对于周向残余应力,分阶段加热钎焊的拉应力峰值较直接加热钎焊减小了11.2%;两种钎焊工艺的周向残余应力的拉应力峰值都大于径向残余应力的拉应力峰值,说明钎焊面的危险部位沿圆周方向。 相似文献
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水下电弧在高压和强烈冷却作用的环境下,其弧压、形态和能量密度都发生了改变,工件的换热条件更发生了显著的变化.文中考虑水下压力对电弧的压缩和水环境中工件换热速度的提高,进行一定的参数假设,建立了湿法熔化极气体保护焊接热过程的数值分析模型,得出了不同水深和不同水流速度下的工件热循环曲线、熔池形状等典型数据.模拟结果表明,随水深增加,熔池的深度增加而宽度减小,各等温线的形状也逐步变得狭窄而且更深;随工件表面水流速度增大,熔池变小,等温面所笼罩的体积也显著减小. 相似文献
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为了研究焊接参数对摩擦塞焊焊接区域温度场的影响,建立了摩擦塞焊焊接的产热模型,并进行摩擦塞焊焊接工艺试验。通过理论分析得出焊接过程中的产热量与焊接参数的关系,试验对理论分析结果进行验证,并深入探讨焊接参数对焊接区域温度场的影响。结果表明:焊接进给速度的改变影响焊接过程中的焊接压力大小,从而影响摩擦塞焊焊接初始阶段的产热,进而影响焊接区域温度场;较高的焊接转速提高摩擦界面材料的升温速率,提高材料塑化,避免焊接缺陷;应选择适当的焊接摩擦时间,尽量匹配较高的转速以缩短焊接摩擦时间。 相似文献
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Finite element simulation of three-dimensional temperature field in underwater welding 总被引:1,自引:0,他引:1
Mathematical models of three-dimensional temperature fields in underwater welding with moving heat sources are built. Double ellipsoid Gauss model is proposed as heat sources models. Several factors which affect the temperature fields of underwater welding are analyzed. Water has little influence on thermal efftciency. Water convection coefftcient varies with the temperature difference between the water and the workpiece , and water convection makes molten pool freeze quickly. With the increase of water depth, the dimensions of heat sources model should be reduced as arc shrinks. Finite element technology is used to solve mathematical models. ANSYS software is used as finite element tool, and ANSYS Parametric Design Language is used to develop subprograms for loading the moving heat sources and the various convection coefftcients. Experiment results show that computational results by using double ellipsoid Gauss heat sources model accord well with the experimental results. 相似文献
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A three-dimensional simulation model for the plasma-MIG welding process, which takes the interaction between the plasma arc and MIG arc into account, is presented and the quasi-steady temperature fields on the workpiece are calculated with the model. The 10 mm-5A06 aluminum alloy is welded and the temperature fields are measured with the thermoelectric couple. The simulation results and measured results show that the biggest deviation of peak temperature between them is below 20 ℃, which indicates good coincidence between the simulation and measurement. 相似文献
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A heat source model for radial friction welding was proposed, which was determined by friction pressure, friction coefficient, material properties and extrusion speed of material. A 3 D model was established to analyze the continuous drive radial friction welding temperature field of 45 steel pipe. The influences of friction pressure, friction time and rotation speed on the temperature of the friction interface were analyzed. The results showed that the temperature on the friction inter face rapidly rose to a peak temperature in initial friction stage and kept constant in the stable friction stage. Welding parameters of friction pressure, friction time and rotation speed had few influences on the peak temperature, while the increase of friction pressure and rotation speed could shorten the time to reach the peak temperature. 相似文献