Calculation of Lankford coefficient from orientation distribution function and modelling of forming limit diagram using Marcniak-Kuczynski hypothesis of geometric instability
Calculation of Lankford coefficient from orientation distribution function and modelling of forming limit diagram using Marcniak-Kuczynski hypothesis of geometric instability
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根据方向分布函数计算 Lankford 系数，并使用几何不稳定性的 Marcniak-Kuczynski 假设对成形极限图进行建模
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发表时间：
2010
期刊：
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通讯作者：
Raja Nagar
中科院分区：
文献类型：
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作者：
A. Raj;Raja Nagar
利用实验室拉伸试验数据和平均塑性应变比，对复杂冲压件的冲压成形性进行了可靠的预测。成形性最好通过Hecker的冲压拉伸方法和绘制成形极限图来评估。在分析上，成形极限图由基于Marciniak & Kuczynski的几何不稳定性分析建模，具有高度的准确性。同时，利用纹理分析得到了模型的平均塑性各向异性比输入参数。本研究采用Schulze背反射技术，通过测量{110}、{200}、{112}和{103}面的四个不完全极图来确定织构。该分析提供了取向分布函数，进而用于计算平均塑性各向异性比。在分析模型中，利用织构数据和拉伸试验、粗糙度测量、密度测量等实验数据，得到了成形极限图。仅在平面应变条件下，得到的理论成形极限图与实验值有显著的偏差。
Complex stampings are developed with the aid of data obtained from laboratory tensile test and average plastic strain ratio that enables the press formability of sheet metals to be reliably predicted. Formability is best assessed by Hecker’s method of punch stretching and drawing the forming limit diagrams. Analytically, the forming limit diagrams are modeled by geometric instability analyses based on Marciniak & Kuczynski with a high degree of accuracy. Also, texture analysis is used to get average plastic anisotropic ratio input parameter to the above model. In the present research, texture is determined by measuring four incomplete pole figures of the planes {110}, {200}, {112} and {103} using Schulze back reflection technique. This analysis provided orientation distribution function which is in turn used to calculate average plastic anisotropic ratio. The data from texture and others experiments, such as tensile test, roughness measurement and density measurement are used in the analytical model to get forming limit diagrams. The theoretical forming limit diagrams obtained show significant departure from the experimentally evaluated ones only in plain strain condition.