磁脉冲胀形管件材料本构参数识别方法

磁脉冲自由胀形后的管件沿轴向材料分布不均匀,且由于其特殊的几何形状无法通过单向拉伸试验获取其材料参数。为获取磁脉冲胀形管的材料参数,提出了一种基于显微压痕试验的磁脉冲自由胀形管件材料参数的获取方法,整个材料参数获取过程包括显微压痕试验、显微压痕试验有限元模型的建立及验证和基于多岛遗传算法(MIGA)的计算反求3部分。通过显微压痕试验获取胀形管轴向不同位置点处的载荷-侵入量曲线,然后通过改变显微压痕有限元模型中的材料参数使仿真得到的载荷-侵入量曲线不断逼近试验的载荷-侵入量曲线,当两曲线在最小二乘意义上达到误差最小时,由仿真得到的材料参数即被认为是真实的材料参数。最后,将反求得到的不同位置点的材料参数整体代入到磁脉冲自由胀形管轴向压溃仿真中,通过比较轴向压溃仿真与轴向压溃试验的变形模式以及力-位移曲线、峰值力、平均力、总吸能等参数来验证参数的准确性。

Indentifying constitutive parameters of magnetic pulse bulging tube

The material distribution of the magnetic pulse bulging tube is uneven along the axial direction, and its material parameters cannot be obtained by the uniaxial tensile test because of its special geometry. To obtain the material parameters of magnetic pulse bulging tube, a method based on the micro-indentation test was put forward, and its obtaining progress included the micro-indentation test, the validation of the finite model of micro-indentation test and the inverse seeking process based on the multi-island genetic algorithm ( MI-GA) . The load-depth curve of magnetic pulse bulging tube at different locations was obtained by the micro-indentation test, and the load-depth curve obtained by the simulation was approached the micro-indentation test curves constantly by changing the material parameters in the finite element model. The material parameters in the finite model were considered to be the real material parameters of the magnetic pulse bulging tube, when the two curves achieved the minimum error in the least-squares sense. Finally, the material parameters in differ-ent locations of the magnetic pulse bulging tube were used into the axial crushing simulation, and the accuracy of parameters was verified by comparing forming type, the force-displacement curve, the mean force and total energy absorption obtained of the stimulation results with those of the experimental results.