Title

Finite Element Simulation Of Damage In Dynamically Loaded Weldments

Abstract

The main goal of the current investigation is to accommodate combined damage softening and thermal softening in structures that experience ductile fracture [1] due to an impulsive loading. A constitutive model first introduced by Johnson-Cook [2], which is sensitive to strain rate effects and temperature softening, is extended to explain the proposed idea. Equations are derived through continuum mechanics theory. Continuum Damage Mechanics (CDM) was first introduced by Kachanov [3] during the fifties. Since then, the topic has been under development by many authors. Numerical simulations are performed in the explicit finite element impact code LS-DYNA [4], Constitutive equations for a viscoplastic model with damage and thermal softening are implemented in the code using a User Defined Subroutine UMAT. The Continuum Damage Mechanics (CDM) model is based on the Bonora formulation [5]. The combined material model, named UMAT 41, is added to the program static library using Digital Visual Fortran (FORTRAN 90). Using the User Defined Material, the solution of an explosive charge and of projectile impact applied to a ring-stiffened welded structure is analyzed to predict fracture. Ring-stiffened structures are widely used in ships, submarines and aircraft, which are subject to explosive or projectile attack Results obtained using models with and without damage softening agree very well with previously published data with respect to crack paths. However, the time histories and thresholds are sensitive to the model used [6J. Projectile impact is also presented in this work.

Publication Date

1-1-2000

Publication Title

ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)

Volume

2000-P

Number of Pages

247-252

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1115/IMECE2000-2181

Socpus ID

85119986378 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85119986378

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