飞机球面框型材拉弯回弹有限元模拟技术

Finite Element Simulation of Springback in Stretch Bending for Aircraft Spherical Frame Profile

针对飞机球面框型材为异形截面的几何特点,基于有限元分析软件Abaqus建立了等效填充离散芯模拉弯成形的有限元模型,通过合理定义边界条件及填充芯模的材料模型,提高了建模效率。根据拉弯过程型材截面弯曲中性层位置不变的假设,建立了夹钳轨迹计算模型,采用位移控制模式对飞机球面框型材拉弯回弹进行了有限元模拟,通过改变中性层位置调整有限元模拟的夹钳轨迹,模拟的回弹结果与实验结果一致,验证了建模方法的有效性。

For the irregular section feature of aircraft spherical frame profile, a equivalence method for applying discrete internal supports in stretch bending process was established by using FEM software Abaqus. Through defining the load boundary conditions and the material model of support, the modeling and simulation efficiency was increased. The jaw traj- ectory calculation model was built according to the assumption that the bending neutral layer position unchanged in stretch bending process. The FEM model of aircraft spherical frame profile stretch bending process which controlled by the dis- placement of machine＇ s jaws was analyzed. By changing the position of the neutral layer to adjust the jaw＇ s trajectory of fi- nite element simulation, the numerical result compared well with experiments. It is proved that the modeling method is effective for studying the springback of profile applying discrete internal supports in stretch bending process.