Estimation of C*-Integral in Thin T-Sections Subjected to Projection and Remote Loading Base on Elastic Stress Concentration Factor

S Shadlou,F Djavanrood,A.R Gowhari-An

doi:10.3844/ajassp.2008.586.596

Abstract

The finite element method has been used to predict the creep rupture parameter, C*-Integral of flat T-section bar subjected to loaded projection and remote loading with a crack or crack-like flaw introduced in the fillet (i.e., high stress) region of the component. In this study, a new dimensionless creeping crack configuration factor, Q* has been introduced. Power low creeping finite element analyses have been performed and the results are presented in the form of Q* for a wide range of components and crack geometric parameters. These parameters are chosen to be representative of typical practical situations and have been determined from evidence presented in the open literature. The extensive range of Q* obtained from the analyses are then used to obtain equivalent prediction equations using a statistical multiple non-linear regression model. The predictive equations for Q*, which are based on the elastic stress concentration factor, can also be used easily to calculate the C*-Integral values for extensive range of geometric parameters. The C*-Integral values obtained from predictive equations were also compared with those obtained from Reference Stress Method (RSM). Finally, creep zone growth behavior was studied in the component during transient time.

Highlights

Continuum mechanics approach based on a macroscopic scale is used
C*-Integral values: The C*-Integral values have been obtained using a numerical procedure based on the Virtual Crack Extension Method (VCEM) suggested by Landes and Begley[13], as follows: C* =
In a similar way to[5], the following equation is derived for the stress concentration factor of a T-section component under remote loading condition: 0.842 + 1.06 ×

Summary

Introduction

Continuum mechanics approach based on a macroscopic scale is used. The rupture fracture parameters in a Projections on plates, bars and tubes are often used remotely loaded cracked component is controlled by the as a means of transmitting axial load between two notch radius, r, plate length, l, crack length, a and the components, e.g., T-shaped flat bars, shouldered remotely applied load, P, as shown in Fig. 1a, for plates/shafts/tubes, wide grooves, filleted transitions cracked components with loaded projections the and many other geometric shapes with similar stress projection length, h and the combined effect of tensile concentration features. In this study at first linear elastic finite element analyses have been performed and elastic stress concentration factor obtained for a wide range of components without crack. Power low creeping finite element analyses have been performed and the result are presented in the form of Q* for a wide range of components, having different stress concentration factors, crack lengths and material creep properties at different temperature.

Results

Conclusion