The three point bending analysis of orthotropic T-beam structural material,using finite element method
| Autor: | Ting-Wei Luo, 羅挺維 |
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| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Orthotropic materials have higher tensile strength but lower shear strength in the longitudinal direction. Therefore, when was used as structural profiles, they tend to cause deformation in three point bending and lead to premature failure due to the presence of shear stress. This is due to that in addition to the tensile stress and the compressive stress, the shear stress is also present on any element of the cross section in the longitudinal of the structural profile when they are subject to three point bending. As a result, the materials are prone to premature failure since the shear stress has already reached the shear strength even though the tensile stress and the compressive stress have not reached the tensile and compressive strength. In this study, finite element method was used to analyze the distributions of the tensile stress, compressive stress and shear stress in orthotropic materials in the longitudinal direction in order to find the most appropriate length to height ratio for orthotropic materials when used as structural profiles. The T-beams of orthotropic materials were simulated by using software analysis with various length over height ratio of 4:1, 8:1, 12:1, 16:1, and 20:1 respectively. Then, in order to explore the order of occurrences of the tensile and shear failures, Materials A(55.16MPa), B(75.84MPa), C(96.53MPa) and D (137.9MPa) with different shear strengths were used to conduct the analysis of three point bending tests, which could be used as the reference for further application and design. The results of the simulation analysis showed that when using Material A, the shear failure occurred first from 8:1 to 20:1 of the length to height ratio; when using Material B, the length to height ratio should be higher than 20:1 to avoid the earlier occurrence of shear failure. Likewise, when using Material C and Material D, the length to height ratio should be higher than 16:1 and 12:1 respectively to avoid the earlier occurrence of shear failure. From the research results of this study, it can be found that when the length to height ratio ranges from 4:1 to 20:1, if the shear strength is higher, a lower length to height ratio is required for the earlier occurrence of tensile failure; on the contrary, if the shear strength is lower, a higher length to height ratio is required for the earlier occurrence of tensile failure. According to the results, this study has found the area with an earlier occurrence of tensile failure rather than shear failure when the length to height ratio ranges from 4:1 to 20:1, which could be used both for the application of design and the prevention of poor structural design. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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