Open AccessResidual Life and Strength Predictions and Life-Enhancement of Structures
Author(s) -
Hideki Okada,
S. N. Atluri
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/760874
Subject(s) - displacement (psychology) , deformation (meteorology) , displacement field , finite element method , mathematics , plasticity , field (mathematics) , truncation (statistics) , geometry , mechanics , physics , structural engineering , mathematical analysis , materials science , thermodynamics , statistics , engineering , composite material , pure mathematics , psychology , psychotherapist
In this paper, a method to quantitatively evaluate the T{sub {var_epsilon}}* integral directly from the measured near-tip displacement field for laboratory specimens made of metallic materials, is presented. This is the first time that such an attempt became a success. In order to develop the procedure, we carefully examine the nature of T{sub {var_epsilon}}* Hence, the nature of T{sub {var_epsilon}}* is further revealed. Following Okada and Atluri (1997), the relationship between energy balance statements for a cracked plate and the T{sub {var_epsilon}}* is discussed. It is concluded that T{sub {var_epsilon}}* quantifies the deformation energy dissipated near crack tip region [an elongating strip of height e] per unit crack extension. In the evaluation of T{sub {var_epsilon}}* integral directly from measured displacement field, the use of deformation theory plasticity (J2-D theory) and the truncation of the near crack integral path on the experimental studies of Omori et el. (1995) are presented, and these show a good agreement with the results of finite element analysis