冷轧材料的各向异性对断裂性能的影响

来源期刊：中南大学学报(自然科学版)1997年第5期

论文作者：陈枫 Kristoph Zaremba

文章页码：90 - 93

关键词：复合加载； 应力强度因子； 各向异性

Key words：mixed mode loading； stress intensity factor； anisotropy

摘    要：为研究材料在冷轧过程中产生各向异性现象对断裂性能的影响,本文通过Ⅰ,Ⅱ型复合到纯Ⅱ型加载及有限元计算,研究了冷轧材料的各向异性对裂纹初始扩展规律和断裂性能的影响。结果表明,这种弱各向异性确实会影响材料的断裂形态。在垂直和平行于轧制的方向上,材料具有不同的断裂力学性状,且当K_I/K_I>1时,2种不同取向的试样大致沿τ_max方向开裂;当K_I/K_I<1时,裂纹会发生尖锐转折并呈Ⅰ型方式断裂。文中也给出了利用复合加载下的P-CMOD曲线确定裂纹临界开裂点的一种简单实验方法。

Abstract: It is well-known that some working processes such as cool-rolling etc. may cause anisotropy in materials, which will affect significantly the fracture behaviour of materials. The influnence of anisotropy in coolrolled material on crack initiation and growth is investigated through mixed mode loading and FEM calculations in this paper. It can be concluded that weak anisotropy does affect the fracture behaviour of material used in this investigation in the rolling direction and perpendicular to the rolling direction. The material is of different fracture behaviours. When K_Ⅱ/K_Ⅰ>1, nearly mode Ⅱ fracture happened to two kinds of specimen, and crack sharply kinked and growth in mode Ⅰ direction, as K_Ⅱ/K_Ⅰ<1. A simple procedure for determination of crack initiation using mixed mode P-CMOD curve is also given in this paper.