Viscoplastic and Creep Crack Growth Analysis by the Finite Element Method.

Abstract

Creep crack growth in a nickel base alloy at elevated temperatures was analyzed through a hybrid experimental-numerical (HEN) procedure. This HEN procedure consisted of simultaneous use of creep crack growth test displacement data from center cracked plate specimens of IN-100 at 1350 F and a theoretical finite element model of the test specimen. A two-dimensional (constant strain triangular) finite element program was developed which accounts for both nonlinear viscoplactic material behavior and changing boundary conditions due to crack growth. Three viscoplastic material models -- (1) Malvern Flow Law, (2) Norton's Creep Law, and (3) Bodner-Partom Flow Law -- were incorporated into the program. These time dependent material models were numerically integrated through time by a linear Euler extrapolation technique. A variable time step algorithm was included that maximized time step size during the analysis while maintaining good accuracy. This program was used as the plane stress theoretical model for the HEN procedure to analyze sustained load creep crack growth.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1980
Accession Number
ADA090344

Entities

People

  • Terry D. Hinnerichs

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Computer Programs
  • Creep
  • Elastic Properties
  • Finite Element Analysis
  • High Temperature
  • J Integrals
  • Materials
  • Materials Laboratories
  • Measurement
  • Mechanics
  • Modulus Of Elasticity
  • Plastic Explosives
  • Plastic Properties
  • Stress Concentration
  • Stress Strain Relations
  • Stresses

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Mechanical Engineering/Mechanics of Materials.
  • Structural Health Monitoring of Composite Structures.