PSI - Issue 13

T.D. Joy et al. / Procedia Structural Integrity 13 (2018) 328–333

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T. D. Joy et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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1. Introduction

Fatigue crack growth in technical structures under cyclic loading is one of the major reasons behind the failure of those structures. The initial damage detected in structures can be of various reasons, such as material imperfections, undetected failures occurred during the designing or manufacturing process, improper fatigue strength calculations and even due to overloading. Such failures lead to costly consequences from financial loss to loss in human lives. Even after spending time and money to improve the designing and production processes, damages tend to occur one after other. Therefore, careful study of the fatigue crack growth is still important. The application areas where consequences of detected fatigue crack growth are wide, ranging from reactor components, pipelines, to all kinds of transport systems like roadways, railways, ships and so on, see Richard et al. (2013). Some examples where fatigue crack growth was discovered are the catastrophic accident that happened in Eschede due to the fatigue crack growth in a rubber-spring railway wheel, see Richard et al. (2005), crack propagation in the frame of a hydraulic press, see Fulland et al. (2005) and fatigue crack growth in an agricultural machine, see Richard et al. (2008). Predicting the behavior of crack growth is thus necessary and very important to avoid accidents occurring again and with the help of simulations and experiments crack growth behavior can be studied. Analytical simulations are restricted to already defined shapes but numerical simulations provide the possibility of using any arbitrary user defined geometry. A DAPCRACK 3D is one such numerical simulation program which uses finite element models wherein the structure is provided to the software along with the mechanical loading and boundary conditions. Generally, in technical structures stresses are induced due to numerous physical reasons. Some of the factors that create stress in a body are external loads such as contact with other bodies and change in temperature. This paper is an attempt to add temperature as an extra boundary condition along with the mechanical boundary conditions that are already available in A DAPCRACK 3D. This procedure is illustrated with the help of an example.

2. The program A DAPCRACK 3D

A DAPCRACK 3D is a numerical automatic crack growth simulation software based on the finite element method. This software is used for simulating the crack growth in 3D models in mixed-mode loading situations. Fig. 1 shows the current architecture of the software A DAPCRACK 3D.

Fig. 1. Structure of the program A DAPCRACK 3D.