Novel Semi-Empirical Model for Forming Limit Prediction of Sheet Metal Material with Regard on Effects of Shear-Tension Loads
Novel Semi-Empirical Model for Forming Limit Prediction of Sheet Metal Material with Regard on Effects of Shear-Tension Loads
复制标题
考虑剪切拉伸载荷影响的金属板材成形极限预测的新型半经验模型
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
M. Liewald
中科院分区：
文献类型：
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作者：
C. Held;M. Sindel;M. Liewald
使用轻质材料在车身设计中提供了大量的强度和重量优势。为了表征汽车工业中专用于深拉深工艺的板材的性能，主要使用成形极限图（FLD）。然而，金属成形技术研究所使用新试样几何形状进行的研究表明，高强度钢板材料的成形性会随着面内拉伸载荷的叠加剪切而改变。因此，在复杂车身零件的深拉深加工过程中，可能会出现包括剪切效应在内的混合应力和应变条件。但目前用常规的flc准则还不能充分描述材料成形性的变化。考虑到这些因素，提出了一种考虑剪切对板料成形性影响的半经验模型。该模型采用一种特殊的应变定义，能够分离剪切和面内张力载荷。对于所谓的剪切成形极限曲线（SFLC）的实验校准，需要几种具有新试样几何形状的标准化和增强的材料测试程序。本文首先提出了材料描述的增强需求，并提出了SFLCModel理论。对于实验校准所需的输入参数由特殊的试样几何形状确定。
The use of lightweight materials offers substantial strength and weight advantages in car body design. For characterization of capability of sheet material dedicated to deep drawing processes in the automotive industry, mainly Forming Limit Diagrams (FLD) are used. However, investigations conducted at the Institute for Metal Forming Technology using new specimen geometries have shown that formability of High Strength Steel Sheet Material changes by superposing shearing on in-plane tension loads. Hence, these mixed stress and strain conditions including shearing effects can occur in deep-drawing processes of complex car body parts. But these changes in materials formability nowadays cannot be described sufficiently by using conventional FLC-criterion. Considering such aspects in defining suitable failure criterions a new semi-empirical model has been developed considering the effect of shearing in sheet metals formability. This novel model is capable to separate shear and in-plane tension loads by using a special strain definition. For experimental calibration of so called Shear Forming Limit Curve (SFLC) several standardized and enhanced material testing procedures with novel specimen geometries are necessary. In this contribution firstly the need of enhanced material description and additionally the theory SFLCModel is presented. For experimentally calibration required input parameters are determined by special specimen geometries.