【作者】 靳鹏；

【导师】 周洪彬；

【作者基本信息】 燕山大学 ， 结构工程， 2008， 硕士

【摘要】 焊接连接是钢结构连接的主要方法之一,而厚板焊接加工会引起接头局部不均匀的热塑性变形和相变,从而产生焊接残余应力。焊接残余应力会影响结构施工和使用全过程,因此在进行钢结构设计和施工之前应该合理估计和考虑焊接残余应力影响。根据厚板焊接形式,考虑40mm厚板X形和V形坡口焊缝,利用有限元计算软件ANSYS分析焊缝残余应力的分布,采用内热源模型模拟温度场,将温度结果作为荷载施加到结构应力计算模型上,得到厚板残余应力的分布特征。根据模拟结果可知:厚板焊缝处节点每次热源的经过都会形成一个峰值,并且焊缝有几道堆焊就有几个波峰;要给定材料各项物理性能参数随温度的变化值,才能得到准确的温度场;焊接表面上厚度方向残余应力值最小,纵向方向残余应力值最大,并且超过了材料本身的屈服强度,这是应力强化的结果;厚板在不同约束下,线约束下的残余应力要比面约束的明显小;在相同的条件下,X形焊缝残余应力要比V形焊缝的要小;厚板残余应力并行运算的时间与网络传输及计算机的配置有关系。最后根据计算结果的对比分析,对厚板残余应力的分析和研究提出了一些建议性的意见,具有一定的实用价值。更多还原

【Abstract】 Welding is a typical steel connection joint, but the Residual stress (RS) is produced by heterogeneous plastic deformations, thermal contractions and phase transformations are induced by the thickness plate manufacturing process. The RS affects the period of construction as well as the period of service. It is reasonable to consider the effects of RS before design and construction.According to plate welding forms, analyzing RS distribution for 40 mm X, V thickness plate by FEM software (ANSYS), and simulating the temperaturefield distribution by inner heat source. Temperature is calculated at first. Then it is applied to the structural model as a load to calculate RS distribution.Research shows that the temperature of nodes in the weld seams reach peak when heat source pass; give the changes value for the physical propertyparameters of the material as the temperature, then can achieve accurate thetemperature field; residual stress in the thickness direction is the minimum andresidual stress values in vertical direction is the largest, and more than the yield strength, this is the result of stress strengthened; in the different constraints,the residual stress under line constrains is less than under area constrains; in the same condition, Than the obvious constraints on the surface in same condition,residual stress of X seam is less than V seam; parallel computing time for thethickness residual stress is relative with network transmission and computersetting.Finally, according to the results of comparative analysis, the thickness residual stress analysis and research provide some recommendations.更多还原