摘要
基于Mandelbrot分形理论,测量了多组不同的冲裁件断面形貌,并计算出每组轮廓的分形维数。结果表明,同一材料的冲裁件断面轮廓分形维数越小,其断面质量越好;针对冲裁过程的数值模拟表明,光亮带的形成是由剪切机理占主导,而断裂带的形成则是由拉伸机理占主导,两种断裂机理共同作用下形成冲裁断面,并形成相应的断面分形维数;通过拉伸断面的分形维数可获得冲裁断面的分形维数上限值。
Characterizing the cross-section quality after blanking test is a difficult task in the punching industrial field.At present,the main evaluation method for the cross-section quality is to measure the relative ratio of smoothsheared length and fracture length.However,the relative length ratio can not reveal the complexity of the fracture surface and can not fully characterize the details of the cross section profile.As a promising theory,fractal theory has been widely used in the metal research field and has a great advantage on the quantitative characterization of the quality of blanking cross sections.Based on the Mandelbrot fractal theory,the relative length ratios of different blanking cross sections were measured and the fractal dimension of each fracture surface were calculated.The results show that with the decrease of the fractal dimensions of the blanking cross section,the quality of fracture surface becomes better.Numerical simulations of the blanking process show that the smooth fracture zone is determined by the shear stress,and the fracture zone is determined by the tensile stress.The upper limit of fractal dimension for the blanking section can be estimated by measuring the fractal dimension of the fracture profile of tensile specimen.
作者
宋劲坤
陈建钧
葛家豪
SONG Jinkun;CHEN Jianjun;GE Jiahao(Shool of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第5期709-714,共6页
Journal of East China University of Science and Technology
基金
国家自然科学基金项目(51675182)。
关键词
冲裁质量
断面轮廓
分形维数
评价方法
blanking quality
cross section profile
fractal dimension
evaluation method
