scholarly journals Optimum Design of a Gearbox for Low Vibration

Author(s):  
Katsumi Inoue ◽  
Dennis P. Townsend ◽  
John J. Coy

Abstract A computer program was developed for designing a low vibration gearbox. The code is based on a finite element shell analysis method, a modal analysis method, and a structural optimization method. In the finite element analysis, a triangular shell element with 18 degrees-of-freedom is used. In the optimization method, the overall vibration energy of the gearbox is used as the objective function and is minimized at the exciting frequency by varying the finite element thickness. Modal analysis is used to derive the sensitivity of the vibration energy with respect to the design variable. The sensitivity is representative of both eigenvalues and eigenvectors. The optimum value is computed by the gradient projection method and a unidimensional search procedure under the constraint condition of constant weight. The computer code is applied to a design problem derived from an experimental gearbox in use at the NASA Lewis Research Center. The top plate and two side plates of the gearbox are redesigned and the contribution of each surface to the total vibration is determined. Results show that optimization of the top plate alone is effective in reducing total gearbox vibration.

1993 ◽  
Vol 115 (4) ◽  
pp. 1002-1007 ◽  
Author(s):  
K. Inoue ◽  
D. P. Townsend ◽  
J. J. Coy

A computer program was developed for designing a low vibration gearbox. The code is based on a finite element shell analysis, a modal analysis, and a structural optimization method. In the finite element analysis, a triangular shell element with 18 degrees-of-freedom is used. In the optimization method, the overall vibration energy of the gearbox is used as the objective function and is minimized at the exciting frequency by varying the finite element thickness. Modal analysis is used to derive the sensitivity of the vibration energy with respect to the design variable. The sensitivity is representative of both eigenvalues and eigenvectors. The optimum value is computed by the gradient projection method and a unidimensional search procedure under the constraint condition of constant weight. The computer code is applied to a design problem derived from an experimental gearbox in use at the NASA Lewis Research Center. The top plate and two side plates of the gearbox are redesigned and the contribution of each surface to the total vibration is determined. Results show that even the optimization of the top plate alone is effective in reducing total gearbox vibration.


Author(s):  
Katsumi Inoue ◽  
Dennis P. Townsend ◽  
John J. Coy

Abstract An optimization method is proposed to reduce the vibration of thin-plate structures. The method is based on a finite-element shell analysis, a modal analysis, and a structural optimization method. In the finite-element analysis, a triangular shell element with 18 degrees of freedom is used. In the optimization, the overall vibration energy of the structure is adopted as the objective function, and it is minimized at the given exciting frequency by varying the thickness of the elements. The technique of modal analysis is used to derive the sensitivity of the vibration energy with respect to the design variables. The sensitivity is represented by the sensitivities of both eigenvalues and eigenvectors. The optimum value is computed by the gradient projection method and a unidimensional search procedure under the constraint condition of constant weight. A computer code, based on the proposed method, is developed and is applied to design problems using a beam and a plate as test cases. It is confirmed that the vibration energy is reduced at the given exciting frequency. For the beam excited by a frequency slightly less than the fundamental natural frequency, the optimized shape is close to the beam of uniform strength. For the plate, the optimum shape is obtained such that the changes in thickness have the effect of adding a stiffener or a mass.


Author(s):  
Qian Li ◽  
Weidong Zhu ◽  
Lixin Zhang ◽  
Minghai Yuan

Buckling destabilization and wrinkling of an ethylene-propylene-diene monomer automobile weather-strip seal in assemblage and its structural optimization were studied in this paper. First, an innovative approach that traces buckling bifurcation paths was developed based on an arc-length method, and algorithmic parameters of the method were defined. A finite element analysis model of the automobile weather-strip seal in assemblage was then developed and analyzed using the arc-length method. The maximum buckling load, the deformation of the seal, and the thickness decrease of the lower tube wall in the critical region where it was prone to wrinkle were obtained by this finite element analysis method. Finally, an optimization seal structure was proposed and analyzed, and the deformations and the thickness decrease of the original and optimal structures in the critical regions were compared. The analysis conclusion implies that the optimal structure is more stable. The proposed analysis and optimization method can shorten the product design cycle, improve the structural stability, and decrease the design and trial-product cost considerably.


2018 ◽  
Vol 55 (4) ◽  
pp. 666-675
Author(s):  
Mihaela Tanase ◽  
Dan Florin Nitoi ◽  
Marina Melescanu Imre ◽  
Dorin Ionescu ◽  
Laura Raducu ◽  
...  

The purpose of this study was to determinate , using the Finite Element Analysis Method, the mechanical stress in a solid body , temporary molar restored with the self-curing GC material. The originality of our study consisted in using an accurate structural model and applying a concentrated force and a uniformly distributed pressure. Molar structure was meshed in a Solid Type 45 and the output data were obtained using the ANSYS software. The practical predictions can be made about the behavior of different restorations materials.


2013 ◽  
Vol 791-793 ◽  
pp. 718-721
Author(s):  
Man Man Xu ◽  
Yu Li ◽  
Sai Nan Xie ◽  
Qing Hua Chen

To analyse the road-header rack and pinion by using the finite element analysis software COSMOS/WORKS. Compared to the traditional analytic calculation and numerical analysis method, it is more intuitively get 28 ° pressure angle spur gear rack meshing stress and strain distribution, which can rack and pinion improvements designed to provide scientific reference.


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