排序方式: 共有51条查询结果,搜索用时 15 毫秒
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曲线路径动态焊接热源建模 总被引:1,自引:0,他引:1
在复杂结构焊接热过程及应力变形分析中,经常遇到曲线焊接路径,其动态焊接热源建模难度大,往往难于实现.为解决该问题,研究了曲线焊接路径热源自动建模方法,实现了曲线上动态焊接热源建模,并为多段直线、环形以及平面曲线焊接路径提供了焊接位姿的定义方法.进一步针对难于用方程直接描述的空间复杂路径、根据焊接结构特征提出辅助圆捕捉法来获取路径上的随动焊枪位姿.利用辅助圆捕捉法,用户可以通过简单的参数输入和CAD操作完成曲线路径动态焊接的热源自动建模. 相似文献
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With more application of welding technology in important structures more attention was paid to the evaluation of the safety of welded structures, the life prediction and decision to repair the welded structures. Based on material fiacture mechanism and Chinese standard of safety evaluations of pressure vessels, an expert system was developed to evaluate the safety of welded pressure vessels. The system can analyze the weld defects in a pressure vessel, convert different kinds of defects into equivalent cracks and obtain their equivalent sizes. Furthermore, the system can calculate the stress and strain in the positions of weld defects and make decision on whether the defects are tolerable or not according to the code. When it is tolerable, the system will calculate the safety margin. The fatigue life can be predicted if the defects undergo fatigue load too. Moreover, data bases are built for storing mechanical properties of material and evaluated results. 相似文献
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A two-equation K-ε turbulent fluid flow model is built to model the heat transfer and fluid flow in gas tungsten arc welding (GTAW) process of stainless steel SUS310 and SUS316.This model combines the buoyancy force,lorentz force and marangni force as the driving forces of the fluid flow in the weld pool.The material properties are functions of temperature in this model.The simulated results show that the molten metal flowing outward is mainly caused by the marangoni convection,which makes the weld pool become wider and shallower.The comparison of the weld pool shape of SUS310 and SUS316 shows that the slight differences of the value of thermal conductivity mainly attributes to the difference of the weld pool shape and the distinction of heat transport in laminar and turbulent model makes large diversity in the simulated results. 相似文献
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弹性状态以低匹配接头能够达到与母材“弯曲等承载能力”(EBLCC)为目标,对低匹配对接接头焊缝几何形状临界条件进行了理论分析,推导了低匹配接头满足弯曲等承载条件的最低余高以及最小熔宽,并给出了弹性状态低匹配弯曲等承载接头设计准则.分析了圆弧替代抛物线曲线的可行性,给出了适用于工程应用方便的三圆相切低匹配弯曲等承载接头设计方法,并进行了弯曲试验验证.结果表明,设计的三圆相切低匹配弯曲等承载接头能够达到与母材弯曲承载能力,满足弯曲等承载要求.文中给出的设计准则与设计方法可使低匹配接头按照母材的弯曲承载能力进行设计,为弹性状态低匹配接头弯曲承载能力设计提供重要的理论依据. 相似文献
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在铝合金搅拌摩擦焊三维体积热源模型建模过程中,轴肩、搅拌针侧面以及搅拌针底面摩擦产热的热流密度加载范围存在不确定性,需校核确定,增加了建模难度。针对该问题,建立三维搅拌摩擦焊热源模型,并确定其不确定热源模型参数,研究了这些参数变化对焊缝温度场的影响规律。在此基础上,基于参数变化影响规律建立了搅拌摩擦焊热源模型参数库,设计了推理规则,形成实现快速建模的铝合金搅拌摩擦焊热源模型专家系统。基于搅拌摩擦焊实验温度场结果验证了专家系统功能,该系统显著降低了搅拌摩擦焊数值模拟建模难度,有利于促进铝合金搅拌摩擦焊数值模拟技术的普及应用。 相似文献
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碳钢金属化电弧喷涂在ABS装置中的应用 总被引:2,自引:0,他引:2
以往,石油化工装置均采用铝或铝合金料仓盛装成品物料.这种料仓虽具有重量轻、强度高、抗腐蚀性强等特点,但这种料仓工程造价高,现场施焊难度较大.为降低工程造价,又保证料仓的使用性能,1996年决定在ABS装置中采用碳钢金属化电弧喷涂的方法对盛装粉料的碳钢基体料仓内表面进行铝喷涂,代替铝镁合金料仓. 相似文献