著者

長嶋 利夫 大本 洋平 谷 周一

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.70, no.691, pp.383-390, 2004-03-25

被引用文献数

1

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Conventional FEM requires that the boundary of the element just matches the crack line to perform stress analyses of structures containing cracks in the field of fracture mechanics. These modeling processes are rather complicated and cannot be performed easily even if the automatic mesh generation technique is utilized. Recently, Belytschko et al. proposed the extended finite element method (X-FEM) based on the concept of partition of unity, and applied this method to the evaluation of the stress intensity factors and perfoming the crack extension simulation. The X-FEM can be used to simplify the modeling of continua containing several cracks and hence perform effective stress analyses related to fracture mechanics. This paper describes the two-dimensional thermal stress analysis of structures containing cracks. Stress intensity factors having mixed modes coupled with mode-I and mode-II are evaluated by M_1-integral method in conjunction with X-FEM. This method is examined in numerical examples of elastic and thermo elastic analyses. The numerical results show that X-FEM is an effective method for performing thermal stress analyses and evaluating stress intensity factors.

著者

長嶋 利夫 三浦 直樹

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.72, no.719, pp.974-981, 2006-07-25

被引用文献数

2

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The extended finite element method (X-FEM), which can model the domain without explicitly meshing the crack surface, can be used to perform stress analyses for efficiently solving fracture mechanics problems. In this study, the constraint condition enforcement for X FEM analysis considering symmetry is presented. Since the interpolation functions utilized in X FEM analysis include the enrichment basis functions, the freedoms of the node on the symmetric plane should be constrained properly in X-FEM model with symmetric conditions. Moreover evaluation of the energy release rate by the domain integral method should be performed considering symmetry conditions. In this paper the constraint conditions for three dimensional X FEM analysis considering symmetric conditions are summarized and the numerical examples using symmetric X FEM models are shown. The proposed procedure can be used to perform efficient X FEM analyses of practical fracture problems.