Technique for Hanger Location of Vehicle Exhaust System Using Finite Element Method

2014 ◽  
Vol 663 ◽  
pp. 485-489 ◽  
Author(s):  
M.S. Noorazizi ◽  
B.A. Aminudin ◽  
H. Faraziah

A simulation technique using a finite element method (FEM) model for predicting, reducing and optimizing vibrations of the exhaust system was developed in this paper. This paper postulates the first stage in the design analysis of an exhaust system. Under excitation of the engine and road surface, the vibration energy of the exhaust system will result in the vibration of the body and produce structure noise transfers to the body from the hanger. These problems will effect or compromise noise, vibration and harshness (NVH) performance of the vehicle. A method called averaged driving DOF displacement (ADDOFD) is used to determine and optimize the exhaust hanger locations in this paper. Based on a sample vehicle, the HyperMesh and MSC Nastran software are adopted for meshing and calculation in the FEM modeling and vibration modal analysis of the exhaust system. Exhaust system’s free-free mode and sum of its eigenvectors are solved using MSC Nastran. Hanger locations are recommended at the position where the ADDOFD is relatively lower. Then static analysis and dynamic analysis of the exhaust system are performed, and finally hanger locations of the exhaust system are selected. When reasonable hanger positions have been decided, the vibration level of the body and the internal noise would have been decreased. This method can effectively select better NVH performance hanger locations in the earlier vehicle development process and can be extended to other types of vehicle, thus is effective for saving both the time and the cost of operation.

2013 ◽  
Vol 392 ◽  
pp. 161-164 ◽  
Author(s):  
M.S. Noorazizi ◽  
B.A. Aminudin ◽  
M.I. Zetty

Under excitation of the engine and road surface, the vibration energy of the exhaust system which will result in the vibration of the body and produce the structure noise transfers to the body from the hanger. In view of these problems will cause noise, vibration and harshness (NVH) performance of the vehicle. A method called averaged driving DOF displacement (ADDOFD) is used to determine and optimize the exhaust hanger locations in this paper. Based on a sample vehicle, the Hyper Mesh and MSC. Nastrans oftware are adopted for meshing and calculation in the FEM modeling and vibration modal analysis of the exhaust system. Exhaust systems free-free mode and sum of its eigenvectors are offered using MSC. Nastran. Hanger locations are recommended at the position where the ADDOFD is relatively lower. Then static analysis and dynamic analysis of the exhaust system are done, and finally hanger locations of the exhaust system are selected. When the reasonable hanger positions have been decided, the vibration level of the body and the internal noise would have been decreased. This method can effectively select better NVH performance hanger locations in the earlier vehicle development process and can be extended to other types of vehicle, thus is instructive for saving both the time and the cost of operation.


2018 ◽  
Vol 178 ◽  
pp. 05014 ◽  
Author(s):  
Andrzej Baier ◽  
Łukasz Grabowski ◽  
Łukasz Stebel ◽  
Mateusz Komander ◽  
Przemysław Konopka ◽  
...  

Numerical analysis of drag values of an electric race car's body. Silesian Greenpower is a student organization specializing in electric race car design. One of the most important issues during the design is reducing the vehicle drag to minimum and is done, mainly, by designing a streamline car body. The aim of this work was to design two electric cars bodies with different shape in Siemens NX CAD software, next a finite elements mesh was created and implemented into the ANSYS Workbench 16.1 software. Afterwards an aerodynamic analysis was carried out, using the finite element method (FEM). Simulations and calculations have been performed in ANSYS Fluent: CFD Simulation software. Computer simulation allowed to visualize the distribution of air pressure on and around car, the air velocity distribution around the car and aerodynamics streamline trajectory. The results of analysis were used to determine the drag values of electric car and determine points of the highest drag. In conclusion car body representing lower drag was appointed. The work includes theoretical introduction, containing information about finite element method, ANSYS and Siemens NX software and also basic aerodynamics laws.


1983 ◽  
Vol 105 (4) ◽  
pp. 251-258 ◽  
Author(s):  
S. I. Oh ◽  
J. J. Park ◽  
S. Kobayashi ◽  
T. Altan

The isothermal forging of a titanium alloy engine disk is analyzed by the rigid-viscoplastic finite element method. Deformation mechanics of the forging process are discussed, based on the solution. The effects of temperature and heat conduction on the forging process are also investigated by coupled thermo-viscoplastic analysis. Since the dual microstructure / property titanium disk can be obtained by controlling strain distribution during forging, the process modeling by the finite element method is especially attractive.


2014 ◽  
Vol 906 ◽  
pp. 318-322 ◽  
Author(s):  
M. Fazlay Rabbey ◽  
Anik Mahmood Rumi ◽  
Farhan Hasan Nuri ◽  
Hafez M. Monerujjaman ◽  
M. Mehedi Hassan

Wing of an aircraft is lift producing component. It makes aircraft airborne by generating lift>weight. The wing must take the full aircraft weight during flying. So, it is very sophisticated task for designing a wing by keeping consideration of every design parameters simultaneously. This paper contains analysis of structural properties of wing by using finite element method. For well-organized design all the variables must be considered from the beginning of the design phase. The design phases for aircraft are: conceptual, preliminary and detail design. Until the preliminary design phase the aircraft structure is not considered. During these phases the material of the wing should be selected in such a way so that it can perform efficiently with less unexpected phenomena (drag) for which responsible properties are displacement, stress etc. Currently the most focusing area for the aero-elastic investigation is to design wing with good aerodynamic shape which will associated with less dragging structural behavior. It helps to reduce SFC (Specific Fuel Consumption) and so the cost. The analysis on that has done through Computational means as well as simulation technique to develop knowledge about the variation of aircraft wing structural properties.


2014 ◽  
Author(s):  
Il-Yong Jang ◽  
Arun John ◽  
Frank Goodwin ◽  
Su-Young Lee ◽  
Byung-Gook Kim ◽  
...  

2008 ◽  
Vol 575-578 ◽  
pp. 1139-1144 ◽  
Author(s):  
Chan Chin Wang

A simulator based on rigid-plastic finite element method is developed for simulating the plastic flow of material in forging processes. In the forging process likes backward extrusion, a workpiece normally undergoes large deformation around the tool corners that causes severe distortion of elements in finite element analysis. Since the distorted elements may induce instability of numerical calculation and divergence of nonlinear solution in finite element analysis, a computational technique of using the Euler’s fixed meshing method is proposed to deal with large deformation problem by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. With this method, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. The proposed method is found to be effective in simulating complicated material flow inside die cavity which has many sharp edges, and also the extrusion of relatively slender parts like fins. In this paper, the formulation of rigid-plastic finite element method based on plasticity theory for slightly compressible material is introduced, and the advantages of the proposed method as compared to conventional one are discussed.


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