薄壁钛管差温剪切弯曲热力耦合有限元模型

Coupled thermal-mechanical finite element model in shear-bending process of Ti-alloy thin-walled tube under differential temperature fields constraints

基于ABAQUS软件环境下的动力显式热力耦合分析模块,建立了TA2薄壁钛管差温剪切弯曲过程模拟三维弹塑性热力耦合有限元模型,讨论了材料模型、热边界条件、单元类型和尺寸、质量放大等有限元建模关键问题,实验验证了有限元模型的可靠性。结果表明:(1)从有限元模型计算的精度和效率考虑,质量放大因子为10000是合理的;(2)单元尺寸越小,热力耦合实体单元模拟管材直线段传力区的温度越低,单元尺寸≤1.0 mm×1.0 mm的热力耦合壳单元模拟管材温度场的分布达到稳定;(3)与热力耦合实体单元相比,采用1.0 mm×1.0 mm热力耦合壳单元模拟的管材厚向应变分布更接近于实验结果。

Based on the dynamic explicit coupled thermal-mechanical （CT） module in software ABAQUS, a 3D CT FE model of TA2 thin-walled tubes was established to simulate shear-bending process under differential temperature fields constraints. The key problems ineluding the material model, the boundary conditions, the element types and sizes, and quality amplification were discussed. The reliability of the FE model was verified by the experimental results. The results show that quality amplification factor of 10000 is the most appropriate when considering the simulation precision and efficiency of the FE model. The smaller the element size is, the lower is the temperature of force transmission area in the straight line of tube; the distribution of simulation temperature field in the tube becomes stable when element size is less than 1.0 mm× 1.0 mm. Compared with the CT continuum elements, the thickness strains distributions simulated by CT shell elements with the element size 1.0 mm × 1.0 mm are closer to the experimental results.