摘要
运用大型有限元软件ANSYS分析CO2气体保护焊接热过程,基于焊接试验结果在前处理器中建立焊缝余高的实体模型,在求解器中采用生死单元技术处理余高。对比不考虑余高、考虑余高但将熔化极焊接简化为非熔化极焊接、采用生死单元技术处理余高三种情况下焊接温度场和熔池形状的数值分析结果表明,占母材体积不足3%的余高对整个焊接温度场分布有明显影响,尤其是对熔池形状以及高温区的分析精度。并采用两种方案(调整热流集中参数和采用三维双椭球体积热源分布模式)进一步提高数值分析精度。通过数值分析结果与焊接试验结果的比较,得出三维双椭球体积热源分布模式可有效提高薄板熔化极焊接热过程数值分析精度。通过对常规熔化极焊接温度场与焊缝余高的探讨,可为大厚度工件多层多道焊接热过程的数值分析奠定基础。
The finite element analysis software ANSYS has been applied to calculate the thermal process in the carbon dioxide gas shielded arc welding. The solid model of weld reinforcement is made in Preprocessor based on experimental results, and the technique of element birth and death is used to deal with the weld reinforcement, which are totally taken as ＂dead＂ elements first and are activated step by step in Solution Processor. Comparing the results for three different cases （without considering the weld reinforcement, taking account of the weld reinforcement but simplifying the process as a non-consumable electrode welding, and adopting the technique of element birth and death to deal with the weld reinforcement）, it is found that the weld reinforcement, which takes up no more than 3% volume of the base metal, has a great influence on the temperature distribution, especially on the numerical analysis precision of the weld profile and the high temperature zone. Two methods （adjusting the heat flux distribution parameter of 2-D Gaussian heat source, and adopting 3-D double-ellipsoid heat source） have been carded out to improve the analysis precision. According to comparison between the predicted results and the experimental ones, it is found that adopting 3-D double-ellipsoid mode of heat source is better to improve the prediction accuracy in modeling consumable electrode arc welding process. All the above work can lay a foundation for multi-pass welding of thick pieces.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第14期80-85,共6页
Journal of Mechanical Engineering
基金
山东省自然科学基金(ZR2010EM073)
中央高校基本科研业务费专项资金(13CX02075A)
中国石油大学(华东)研究生创新基金(CX2013048)资助项目
关键词
焊缝余高
生死单元技术
高斯热源
双椭球热源
Weld reinforcement Element birth and death technique Gauss heat source Double-ellipsoid heat source
