EFFECT OF TRIAXIAL STRESS CONSTRAINT ON THE DEFORMATION AND FRACTURE OF POLYMERS

• 来源期刊: 力学学报（英文版）
• 学科: 物理学
• 年，卷（期）: 2002,（5）
• 页码范围: 480-493
• 页数: 14页
• 分类号: O3
• 语种: 英文

摘要

One purpose of this paper is to give a brief overview on the researchstatus of deformation, fracture and toughening mechanisms of polymers, includingexperimental, theoretical and numerical studies. Emphasis is on the more recentprogresses of micromechanics of rubber particle cavitation and crazing, and the de-velopment of fracture criteria for ductile polymers.The other purpose is to study the effect of triaxial stress constraint on the deforma-tion and fracture behavior of polymers. Polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) and PC/ABS alloy are considered in this investigation. A series ofcircumferentially blunt-notched bars are used to experimentally generate different tri-axial stress fields. The fracture surfaces of specimens with different notch radius areexamined by scanning electron microscope (SEM) to study the fracture and tough-ening mechanisms of polymer alloy. It is shown that the triaxial stress constrainthas a significant effect on the deformation, fracture and toughening of PC, ABS andPC/ABS alloy. We will also discuss the extent to which a micromechanics criterionproposed by the first author can serve as a fracture criterion for ductile polymers.A new ductile fracture parameter is emphasized, which can be employed to evaluatethe fracture ductility of polymers. Stress state independence of the parameter for thePC, ABS and PC/ABS alloy has been experimentally verified.