Research on Problems of Fracture Mechanics About the Spur Gears with Cracked Tooth
Zhang Dawei,
Wang Shufeng
Issue:
Volume 2, Issue 6, December 2017
Pages:
93-99
Received:
12 July 2017
Accepted:
19 July 2017
Published:
30 October 2017
Abstract: Taking the spur gear as the object of study, based on the dynamic analysis of gear transmission system, the dynamic stress intensity factors of cracked gear teeth are studied by using ANSYS software. The calculation of dynamic stress intensity factor is realized by ANSYS parametric design language. Firstly, the involute tooth profile equation and the root transition curve equation of the gear teeth in the rectangular coordinate system are established, and the geometric model of the gear tooth is generated, and the crack is generated at the root of the gear tooth. Then, the mesh is divided and the loads are applied. Finally, the stress intensity factors at different crack depths are calculated and analyzed. The results show that the stress intensity factor varies significantly with the variation that location of the meshing point and the depth of the crack.
Abstract: Taking the spur gear as the object of study, based on the dynamic analysis of gear transmission system, the dynamic stress intensity factors of cracked gear teeth are studied by using ANSYS software. The calculation of dynamic stress intensity factor is realized by ANSYS parametric design language. Firstly, the involute tooth profile equation and t...
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Analysis of Optimum Butt Welded Joint for Mild Steel Components Using FEM (ANSYS)
Collins Eruogun Etin-osa,
Joseph Ifeanyi Achebo
Issue:
Volume 2, Issue 6, December 2017
Pages:
100-109
Received:
18 February 2017
Accepted:
19 May 2017
Published:
2 November 2017
Abstract: Weld failure due to vibrations can be minimized if appropriate measure is implemented to ensure forced vibration is not equal to the natural frequency of the material. This research focuses on determining the optimum butt welded joint, by analyzing the various natural frequencies and mode shape response obtained from five different types of butt joints. In this study, modal analysis was carried out using ANSYS 14.5 on two mild steel plates of dimensions 250mm by 175mm by 25mm welded together. Five different geometries of butt joints namely: single V groove butt weld, double V groove butt weld, single U groove butt weld, double U groove butt weld and square groove butt welded joints were examined. The natural frequencies and mode shape deformations obtained were compared with the natural frequency of mild steel of zero weld plate of dimension 500mm by 175mm by 25mm. Natural frequency of zero weld plate was found to be 51.549Hz, it was observed that the natural frequencies of the five joints mentioned were of close range in increasing order of 45.020Hz, 47.949Hz, 48.506Hz, 49.264Hz and 50.342Hz for square groove butt welded joint. The natural frequency of the square groove butt welded joint was observed to be closest to the zero weld plate; therefore we recommend square groove butt weld as optimum butt weld for engineering constructions because it failed the least when compared to other types of butt joints.
Abstract: Weld failure due to vibrations can be minimized if appropriate measure is implemented to ensure forced vibration is not equal to the natural frequency of the material. This research focuses on determining the optimum butt welded joint, by analyzing the various natural frequencies and mode shape response obtained from five different types of butt jo...
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Geant4 Based Space Radiation Application for Planar and Spherical Geometries
Issue:
Volume 2, Issue 6, December 2017
Pages:
110-114
Received:
4 November 2017
Accepted:
17 November 2017
Published:
18 December 2017
Abstract: A space radiation application is developed based on Geant4 tool kit. Even though there are many space radiation applications like MULASSIS (MUlti-LAyered Shielding SImulation Software); the application developed here offers more flexibility in choosing the physical models. It can be used to analyze the spherical geometries directly in addition to the planar geometries. In this paper both planar and spherical geometries of aluminum (Al), polyethylene (CH2) and liquid hydrogen (lH2) materials are analyzed with the help of dose-depth curves. The hydrogen, helium and Fe particle spectra of Galactic Cosmic Radiation (GCR) radiation are used in the estimation of doses. The total equivalent doses for the periods of 1 Yr are evaluated for aluminum, polyethylene and liquid hydrogen materials respectively and the liquid hydrogen is found to be more effective shielding material. These doses are compared to NCRP 2000 (National Council on Radiation Protection and Measurements) career dose limits to analyze the radiation risk for astronauts. The doses in case of planar geometries are well below the career limits of male as well female astronauts of age 35Yrs but those that in case of spherical geometries are well above the career limits for female astronauts of the same age. Doses for spherical geometries are below the career limits of male astronauts of same age only when areal densities of shield materials reach 100g/cm2. The dose in spherical geometry is found to be ~4.4 times to that of planar geometry when Al material of 10 g/cm2 is exposed to GCR hydrogen spectrum. This is in agreement with the estimations of previous studies. The effect of geometry on the dose levels received by astronauts is also analyzed. It is found that the reduction in dose is about 10% more in spherical geometry than in planar geometry of the Al material. This is observed when the Al material is exposed to GCR hydrogen spectrum and its thickness is varied from 10 g/cm2 to 120 g/cm2.
Abstract: A space radiation application is developed based on Geant4 tool kit. Even though there are many space radiation applications like MULASSIS (MUlti-LAyered Shielding SImulation Software); the application developed here offers more flexibility in choosing the physical models. It can be used to analyze the spherical geometries directly in addition to t...
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