动车组车体结构多层多道焊接变形的有限元模拟与验证

Finite Element Simulation and Verification of Multi-Layer Multi-Pass Welding Deformation in EMU Carbody Structures

  • 摘要: 针对大型工程结构焊接变形数值模拟存在的计算效率与精度难以兼顾的问题,本文提出一种基于局部-整体映射策略的有限元模拟方法。该方法通过建立局部焊缝精细模型完成温度场分析,将获得的热循环曲线通过映射算法施加于整体结构模型,构建了快速焊接应力变形预测体系。特别针对动车组底架焊接中普遍存在的多层多道焊工艺,提出热循环叠加等效算法,建立多道次热输入与等效单次热源的叠加关系,实现了多道次焊接的简化建模。并通过试验测试,验证了该方法的有效性,结果表明:当采用热循环叠加后的等效单次加载时,焊接变形的相对误差<5%,计算耗时显著降低。研究证明该方法在保证计算精度的前提下,通过热源映射技术和叠加算法显著提高了计算效率,为大型复杂焊接结构的工艺优化提供了高效的数值分析手段。

     

    Abstract: To address the challenge of balancing computational efficiency and accuracy in numerical simulation of welding deformation for large-scale engineering structures, this paper proposes a finite element simulation method based on a local-global mapping strategy. The method establishes a refined local weld model for temperature field analysis and applies the obtained thermal cycle curves to the global structural model through a mapping algorithm, thereby establishing a rapid prediction system for welding-induced stress and deformation. Specifically targeting the prevalent multi-layer multi-pass welding process in EMU (Electric Multiple Unit) underframe fabrication, a thermal cycle superposition equivalent algorithm is developed to establish the cumulative relationship between multi-pass heat inputs and an equivalent single-pass heat source, enabling simplified modeling of multi-pass welding processes. Experimental validation demonstrates the effectiveness of the proposed method, revealing that when using the equivalent single-pass loading derived from thermal cycle superposition, the relative error in welding deformation remains below 5%, with a significant reduction in computational time. The study confirms that this method significantly enhances computational efficiency through thermal source mapping and superposition algorithms while maintaining accuracy, providing a novel numerical tool for process optimization in large-scale complex welded structures.

     

/

返回文章
返回