基于拟全量理论的多步正向成形模拟方法

发布时间：2019-06-15 10:38

【摘要】：在全量理论的基础上,引入增量思想,构建了多步正成形算法。其基本原理是在一步正成形的基础上,适当增加了若干个中间步,依次计算各中间步之间的应变改变量,并以分量形式累加到当前步的总应变,基于全量理论进行Newton-Raphson迭代计算,并将计算结果以应变分量的形式累加到下个中间步计算中,计算对应的弹塑性本构矩阵,从而在计算过程中体现加载历史的影响,提高了最终的模拟结果精度。设计了方盒件多行程实验方案,采用电腐蚀方法在初始坯料上刻上圆形网格,进行了10 mm、20 mm、30 mm、40 mm、50 mm五个不同行程的方盒件成形实验。利用光学方法测量网格变形量并推算出网格应变量,使用超声测厚仪测量板料不同行程的厚度变化量。通过几种不同算法在计算精度和计算效率上的对比,证明了多步正成形算法的有效性。
[Abstract]:On the basis of the full quantity theory, the incremental idea is introduced to construct the multi-step orthopaedic forming algorithm. The basic principle is that on the basis of one step positive forming, several intermediate steps are properly added, and the strain change variables between each intermediate step are calculated in turn, and the total strain is accumulated to the current step in the form of component. The Newton-Raphson iterative calculation is carried out based on the full quantity theory, and the calculation results are accumulated into the next intermediate step in the form of strain component, and the corresponding elastic-plastic constitutive matrix is calculated. Thus, the influence of loading history is reflected in the calculation process, and the accuracy of the final simulation results is improved. The multi-stroke experimental scheme of square box parts is designed. The circular grid is engraved on the initial billet by electric corrosion method, and the forming experiments of five different stroke square box parts with 10 mm,20 mm,30 mm,40 mm,50 mm are carried out. The grid deformation is measured by optical method and the grid strain is calculated, and the thickness variation of sheet metal with different stroke is measured by ultrasonic thickness gauge. The effectiveness of the multi-step shaping algorithm is proved by comparing the computational accuracy and efficiency of several different algorithms.
【作者单位】：南京工程学院汽车与轨道交通学院;吉林大学汽车仿真与控制国家重点实验室;
【基金】：国家自然科学基金项目(51075187) 南京工程学院校级科研基金项目(YKJ201433)
【分类号】：U466

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