Material Damage and Failure iMechanica（物质损失和失败iMechanica）.pdf

ABAQUS/Explicit: Advanced Topics Lecture 9 Material Damage and Failure Copyright 2005 ABAQUS, Inc. ABAQUS/Explicit: Advanced Topics L9.2 Overview • Progressive Damage and Failure • Damage Initiation for Ductile Metals • Damage Evolution • Element Removal • Failure in Fasteners Copyright 2005 ABAQUS, Inc. ABAQUS/Explicit: Advanced Topics Progressive Damage and Failure Copyright 2005 ABAQUS, Inc. ABAQUS/Explicit: Advanced Topics L9.4 Progressive Damage and Failure • ABAQUS offers a general capability for modeling progressive damage and failure in engineering structures. – Material failure refers to the complete lo of load carrying capacity that results from progre ive degradation of the material stiffne . – Stiffne degradation is modeled using damage mechanics. • Progressive damage and failure can be modeled in: – Bulk materials • Continuum constitutive behavior – used in conjunction with the Mises, Johnson-Cook, Hill, or Drucker-Prager plasticity model • This is the primary focus of this lecture. – Interface materials • Cohesive elements with a traction-separation law • This was discu ed in Lecture 7, Constraints and Connections. Copyright 2005 ABAQUS, Inc. ABAQUS/Explicit: Advanced Topics L9.5 Progressive Damage and Failure • Two distinct types of bulk material failure can be modeled with ABAQUS/Explicit – Ductile fracture of metal • Void nucleation, coalescence, and growth • Shear band localization – Necking instability in sheet-metal forming • F