Advanced Methodologies for Fracture Analysis and Damage Tolerant Evaluation

Nagesh R Iyer

Nagesh R Iyer Distinguished Emeritus Professor, Academy of Scientific and Innovative Research (AcSIR) and Former Director, CSIR-Structural Engineering Research Centre (CSIR-SERC)

Keywords: Crack Closure, Linear Elastic Fracture Mechanics, Stress Intensity Factor, Strain Energy Release Rate, Damage Tolerant Design, Remaining Life, Residual Strength, Extended Finite Element Method

Abstract

The objective of the paper is to present the advanced methodologies for fracture analysis and damage tolerant evaluation of metallic structural components for efficient and safe design of structural systems meeting the functional criteria. An efficient and novel Numerically Integrated-Modified Virtual Crack Closure Integral (NI-MVCCI) technique has been demonstrated for 4-noded bilinear, 8-noded (regular & quarter-point), 9-noded Lagrangian and 12-noded cubic isoparametric family of finite elements. Another advanced numerical method, Extended Finite Element Method (XFEM) for fracture analysis of cracked stiffened panels has been discussed. Methodologies for crack growth and remaining life assessment of structural components under constant and variable amplitude loading have been presented. Brief description on residual strength evaluation has been provided. Numerical studies on fracture analysis to compute Strain Energy Release Rate (SERR), G and stress intensity factor (SIF) and remaining life assessment and residual strength evaluation have been
conducted and the results are compared with the respective analytical/experimental results.