| Summary: | 碩士 === 國立成功大學 === 機械工程學系 === 107 === In this article, the quadtree element-free Galerkin method (QEFGM) is proposed for automatically configuring the background cells. The thesis explores fracture analysis of piezoelectric elliptical tube subject to internal pressure and thermal loadings. The content of this paper is mainly divided into three parts to discuss.
First of all, the stress intensity factors (SIF) is calculated by the QEFGM and the traditional element-free Galerkin method (EFGM). The errors compared with the literature are 1.28% and 5.17%, respectively. Compared with the traditional method, the accuracy of the QEFGM is increased by 75.24%. Therefore, the correctness and superiority of the QEFGM proposed in this paper is proved.
Secondly, this paper discusses the effects of temperature changes on the SIF. It is found that the crack of the material is closed when the temperature rises. Further, the fracture analysis is carried out with four different temperature distributions. It is found that the temperature difference of the inner edge of the tube is an important factor affecting the physical field and the SIF.
Finally, the thesis explores the influence of geometric shape on the SIF. The fracture analysis is carried out with four ellipses with different axial ratios and three super ellipses of different powers. It is found that the SIF increases when the axial ratio and the powers increase.
In this paper, various fracture analysis of piezoelectric material is carried out under different working conditions. It is hoped that the research results can provide effective information for the industry in extending material life cycle.
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