In order to simulate transverse bending and longitudinal welding in fabricating high strength S690 cold-formed circular hollow sections, and more importantly, effects due to these fabrication processes on structural behaviour of these sections under axial compression, an integrated and coordinated numerical modelling approach using coupled analyses is proposed. Details of these mechanical, thermal, thermomechanical and structural analyses of these sections under various boundary and loading conditions imposed during fabrication are presented. Two-dimensional models with large deformation plane strain elements are employed to perform transverse bending while two compatible three-dimensional models with heat transfer elements and stress elements are employed to simulate sequentially coupled heat transfer and thermomechanical analyses to simulate longitudinal welding. These fabrication-induced residual stresses and strains are then incorporated as initial material imperfections into the third compatible three-dimensional model with stress elements for structural analyses under axial compression. These models have been carefully calibrated against data obtained from various stages of fabrication and also from compression tests. The proposed modelling approach is one of the few attempts available in the literature that develops a series of integrated and coordinated models to examine the structural behaviour of high strength S690 cold-formed circular hollow sections under axial compression with a direct simulation on various fabrication processes without the use of simplified residual stress patterns.

为了模拟制造高强度 S690 冷弯圆形空心型材时的横向弯曲和纵向焊接，更重要的是，为了模拟这些制造工艺对这些型材在轴向压缩下的结构行为的影响，使用耦合的集成协调数值建模方法提出分析。介绍了这些部分在制造过程中施加的各种边界和载荷条件下的这些机械、热、热机械和结构分析的详细信息。采用具有大变形平面应变单元的二维模型进行横向弯曲，同时采用两个兼容的具有传热单元和应力单元的三维模型来模拟连续耦合的传热和热机械分析，以模拟纵向焊接。然后将这些制造引起的残余应力和应变作为初始材料缺陷合并到第三个兼容的三维模型中，该模型具有用于轴向压缩下结构分析的应力元素。这些模型已经根据从不同制造阶段和压缩测试中获得的数据进行了仔细校准。