Abstract

Springback simulation of stamped sheet metal components using finite element method depends on the accuracy of appropriate material models and consideration of appropriate experimental strategies. In this work, tension-compression tests with different strategies, e.g. tension-compression, compression-tension up to various strain levels and multicycle compression-tension tests were conducted to determine parameters of the Yoshida-Uemori (Y-U) nonlinear dynamic hardening model using optimization analysis software LS-OPT. Finite element simulations with LS-DYNA were performed to predict springback behavior of both the advanced high strength steel MP980 (a 980 MPa grade multiphase steel) and aluminum alloy 6022-T4, which was then compared to measurements of stamped U-channel specimens. Results suggest that although the various tension-compression testing strategies can significantly affect the determined values of Yoshida-Uemori model parameters, springback prediction accuracy with this model does not depend on the associated variation of model parameters, at least for the two-dimensional sidewall curl of a U-channel shape. For materials (e.g. MP980) exhibiting a clear Bauschinger effect but insignificant texture anisotropy, the selection of suitable yield criteria (e.g. Hill48), the consideration of elastic modulus degradation combined with the Y-U model can obviously increase the accuracy of springback prediction. In contrast, materials (e.g. AA6022-T4) that exhibit little Bauschinger effect but have significant texture anisotropy, the use of a yield criterion that accounts for anisotropy (e.g. YLD2000-2D) is more important for improving the accuracy of springback prediction.

中文翻译：

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本构模型对MP980和AA6022-T4回弹预测的影响。

摘要

使用有限元方法对钣金冲压件进行回弹模拟取决于适当材料模型的准确性以及适当的实验策略的考虑。在这项工作中，进行了具有不同策略的拉伸压缩测试，例如拉伸压缩，达到各种应变水平的压缩拉伸以及多循环压缩拉伸测试，以通过优化确定吉田植茂（YU）非线性动态硬化模型的参数。分析软件LS-OPT。用LS-DYNA进行了有限元模拟，以预测先进的高强度钢MP980（980 MPa级多相钢）和铝合金6022-T4的回弹行为，然后将其与冲压U型钢试样的测量结果进行比较。结果表明，尽管各种拉伸压缩测试策略都可以显着影响吉田植森模型参数的确定值，但该模型的回弹预测精度至少与二维侧壁卷曲无关，并不取决于模型参数的相关变化。 U形通道的形状。对于表现出明显的鲍辛格效应但质地各向异性不明显的材料（例如MP980），选择合适的屈服准则（例如Hill48），考虑弹性模量下降并结合YU模型可以明显提高回弹预测的准确性。相反，材料（例如Aa6022-T4）表现出的鲍辛格效应很小，但具有明显的各向异性，因此使用了屈服准则来解释各向异性（例如