焊管FFX成形初成形段显式动力仿真及实验

Simulation and experiment on pre-forming section of welded pipe FFX forming with explicit dynamic algorithm

针对直缝焊管FFX成形过程涉及复杂的非线性问题，对Ф168mm焊管FFX成形机组初成形段建立有限元模型，利用显式动力算法对直缝焊管FFX成形过程进行仿真计算，获得了初成形段钢带的等效塑性应变分布及几何变形。结果表明，FFX成形初成形段板带各位置截面的最大等效塑性应变集中在板带边缘区域，同时发现板带截面上等效塑性应变呈“L”状分布；板带的几何变形良好，变形均匀且边部曲线平滑，无边浪和鼓包等缺陷产生。将板带各成形截面在模拟仿真中得到的开口距离与实际测量中得到的开口距离进行了对比，结果表明最大相对误差为4．49％，取得了较高吻合度，验证了有限元模型的正确性。

Considering the complex nonlinearity in flexible forming excellent （FFX） process of welded pipes, the finite element model of the pre-forming section of Ф168 mm welded pipe FFX forming mill was established and the FFX forming process was simulated adopting explicit dy- namic algorithm. The distribution of the effective plastic strain and the geometrical deformation of strip at the pre-forming section were obtained. The results show that the maximum equivalent plastic strain at the cross section of each position in pre-forming section occurs at the strip edge in the FFX forming. The distribution of the equivalent plastic strain on the strip section is like L shape. The geometrical deformation of the steel strip is good, the deformation is uniform and smooth without side wave and bulge defect. The simulation result and the actually measured result of the opening distance were compared, the results show that the maximum relative error is 4. 49%, the anastomosis is great which validates the corecctness of the finite element model.