A finite elements based approach for fracture analysis of welded joints in construction machinery

Karagöz, Taner
This study aims to develop a computer program to perform finite elements based fracture mechanics analyses of three dimensional surface cracks in T-welded joints of construction machinery. The geometrical complexity of the finite elements models and the requirement of large computer resources for the analyses necessitate the use of shell elements for general stress distribution optimization. A sub-modeling technique, together with a shell to solid conversion method, enables the user to model a local region and analyze it by defining the weld and crack parameters. It is assumed that the weld material is the same with the sheet metal material and the surface cracks are considered to occur on two weld toes and weld root. The surface cracks are assumed to have a semi elliptical crack front profile. In order to simulate the square-root strain singularity around the crack front, collapsed 20-node three dimensional brick elements are utilized. The rest of the local model is modeled by using 20-node three dimensional brick elements. The main objective of this work is to calculate the mixed mode energy release rates around the crack front for a sub-model of a global shell model by using J-integral method.


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The aim of this study is to model three dimensional surface crack problems in fillet welds. It is assumed that weld material has the same material properties with the sheet metals. The surface crack is considered to occur at two regions; one at the weld root and the other at the weld toe. The surface crack is assumed to have a semi elliptical crack front profile. The surface crack problem is analyzed under mechanical loading and the models are built up by three dimensional finite elements. Around the crack...
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Citation Formats
T. Karagöz, “A finite elements based approach for fracture analysis of welded joints in construction machinery,” M.S. - Master of Science, Middle East Technical University, 2007.