Open Access

ARTICLE

Residual Strength Evaluation of Unstiffened and Stiffened Panels under Fatigue Loading

by A. Rama Ch,ra Murthy¹, G.S. Palani¹, Nagesh R. Iyer¹

1 Scientist, Structural Engineering Research centre, CSIR, CSIR Campus, Taramani, Chennai – 600 113, India, email: murthyarc@sercm.org, pal@sercm.org, nriyer@sercm.org.

Structural Durability & Health Monitoring 2009, 5(3), 201-226. https://doi.org/10.3970/sdhm.2009.005.201

Abstract

This paper presents methodologies for residual strength evaluation of metallic structural components under fatigue loading. Structural components include plate panels of different crack configurations with and without stiffeners. For stiffened panels, stress intensity factor (SIF) has been computed by using parametric equations based on numerically integrated modified virtual crack closure integral (NI-MVCCI) technique. As a part of residual strength evaluation, remaining life has also been predicted by using standard crack growth models. Various methodologies for residual strength evaluation, namely, plastic collapse condition, fracture toughness criterion and remaining life approach have been described. From the studies, it has been observed that the predicted residual strength using remaining life approach is lower compared to those predicted by using other two approaches and will govern the design. In the case of stiffened panels, residual strength has been predicted by using remaining life approach and it is observed that the residual strength increases with the increase of stiffener size. Expressions for residual strength have been proposed considering various stiffener sizes, stiffener position and type of stiffener, which will be useful for designers to design the structural components/structures against fatigue and fracture.

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