Stress and fracture analysis of short flat bars with projections using boundary element method

Mechanical components generally contain geometric discontinuities such as fillet, grooves and sharp edges. These discontinuities are often known as stress raisers since stress concentrates around and caused the local stress to be significantly high. Cracks are likely to initiate and propagate from t...

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Main Author: Ang, Jarreal Jia Xiang
Other Authors: Ang Hock Eng
Format: Final Year Project (FYP)
Language:English
Published: Nanyang Technological University 2022
Subjects:
Online Access:https://hdl.handle.net/10356/159106
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author Ang, Jarreal Jia Xiang
author2 Ang Hock Eng
author_facet Ang Hock Eng
Ang, Jarreal Jia Xiang
author_sort Ang, Jarreal Jia Xiang
collection NTU
description Mechanical components generally contain geometric discontinuities such as fillet, grooves and sharp edges. These discontinuities are often known as stress raisers since stress concentrates around and caused the local stress to be significantly high. Cracks are likely to initiate and propagate from these high localized stress points. This poses the potential of mechanical components to fail earlier than expected. Short flat bars with projections which contain fillets which is a geometric discontinuity are studied in this project and Boundary Element Method based computational program – BIE2DRSE-A was employed to generate results for analysis. In the first part of the project, stress analysis was carried out on short flat bars with projections subjected to different types of loading – axial or shear, and restraint – remote or local. High stress concentration region was identified through the analysis of stress distribution profile. The effect of varying geometric parameters had on SCF was also examined. Comparisons were done between the results obtained in this report and the published finite element analysis data. It was concluded that the results are in good agreement. Results have shown that stress concentrates around the fillet region and the increase in fillet radius reduces the stress concentration effect. In the second part of the project, crack was modelled at the highest localized stress point of the fillet region to facilitate fracture analysis of the short flat bars with projections. Studies were conducted over a range of crack inclination angle to understand the effect of varying geometric parameters and crack size have on the overall SIF which is an important parameter in characterizing crack behavior. It was found that overall SIF increases with crack size and decreases with increasing geometric parameter ratios studied. Furthermore, results have also shown that the direction of crack propagation does not change much with its initial crack angle.
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spelling ntu-10356/1591062023-03-04T20:12:38Z Stress and fracture analysis of short flat bars with projections using boundary element method Ang, Jarreal Jia Xiang Ang Hock Eng School of Mechanical and Aerospace Engineering MHEANG@ntu.edu.sg Engineering::Mechanical engineering Mechanical components generally contain geometric discontinuities such as fillet, grooves and sharp edges. These discontinuities are often known as stress raisers since stress concentrates around and caused the local stress to be significantly high. Cracks are likely to initiate and propagate from these high localized stress points. This poses the potential of mechanical components to fail earlier than expected. Short flat bars with projections which contain fillets which is a geometric discontinuity are studied in this project and Boundary Element Method based computational program – BIE2DRSE-A was employed to generate results for analysis. In the first part of the project, stress analysis was carried out on short flat bars with projections subjected to different types of loading – axial or shear, and restraint – remote or local. High stress concentration region was identified through the analysis of stress distribution profile. The effect of varying geometric parameters had on SCF was also examined. Comparisons were done between the results obtained in this report and the published finite element analysis data. It was concluded that the results are in good agreement. Results have shown that stress concentrates around the fillet region and the increase in fillet radius reduces the stress concentration effect. In the second part of the project, crack was modelled at the highest localized stress point of the fillet region to facilitate fracture analysis of the short flat bars with projections. Studies were conducted over a range of crack inclination angle to understand the effect of varying geometric parameters and crack size have on the overall SIF which is an important parameter in characterizing crack behavior. It was found that overall SIF increases with crack size and decreases with increasing geometric parameter ratios studied. Furthermore, results have also shown that the direction of crack propagation does not change much with its initial crack angle. Bachelor of Engineering (Mechanical Engineering) 2022-06-10T01:21:35Z 2022-06-10T01:21:35Z 2022 Final Year Project (FYP) Ang, J. J. X. (2022). Stress and fracture analysis of short flat bars with projections using boundary element method. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/159106 https://hdl.handle.net/10356/159106 en B336 application/pdf Nanyang Technological University
spellingShingle Engineering::Mechanical engineering
Ang, Jarreal Jia Xiang
Stress and fracture analysis of short flat bars with projections using boundary element method
title Stress and fracture analysis of short flat bars with projections using boundary element method
title_full Stress and fracture analysis of short flat bars with projections using boundary element method
title_fullStr Stress and fracture analysis of short flat bars with projections using boundary element method
title_full_unstemmed Stress and fracture analysis of short flat bars with projections using boundary element method
title_short Stress and fracture analysis of short flat bars with projections using boundary element method
title_sort stress and fracture analysis of short flat bars with projections using boundary element method
topic Engineering::Mechanical engineering
url https://hdl.handle.net/10356/159106
work_keys_str_mv AT angjarrealjiaxiang stressandfractureanalysisofshortflatbarswithprojectionsusingboundaryelementmethod