Numerical Simulation of Rollover Test on Complete Vehicle Considering the Effects of Welding Joints
| Autor: | Hung-Wei Ho, 何宏瑋 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 Buses are the high loading capacity transportation on the road. When a major accident happened, the passengers would be serious injury. When a rollover accident of a bus happened, the damage often occurred in the weld zone. For passengers’ safety, the design of superstructure of the bus should consider the weld zone which would affect the strength of a bus rollover accident. From the previous numerical analysis, the weld zone often idealistic assemble at an concurrent way. But those analysis did not account of the effects of welding. This paper adopted nonlinear software LS-DYNA to study the rollover strength of bus. At first, this paper added the failure criteria of both fillet welding and butt welding to the extrusion simulation analysis of a bus frame structure. Then compared the difference with the result of idealistic assemble at concurrent way. The result densely match with the previous experiment which considered welding. The elongation which the weld zone of roof structure failure is only 7.4% different from the previous experiment. The elongation which the weld zone of pillar structure failure is only 3.7% different from the previous experiment. The weld zone of bottom did not failure, so the result of numerical analysis is match with the previous experiment. Secondly, this paper based on the regulation, ECE R66(Economic Commission for Europe), to establish a computer simulation of bus rollover test, and used a certain type of Europe bus to study the effect of both the concur rant and the welding failure. Meanwhile, this paper tested whether the Europe bus is match the ECE R66. The result showed that the finite element model of the ideal concurrent way can absorbed energy due to the stiffer structure. When considering the finite element model of the welding effect, due to the failure criteria, the mechanical behavior is more closer to the actual situation. Also, the result showed that both the concurrent and the welding did not pass the regulation ECE R66. Finally, this paper adopted two common size of pipe, 40mm×80mm×3mm and 60mm×40mm×3mm, to study The different impact on structure strength when using different size of ring cross-section. The result showed that the 40mm×80mm×3mm pipe of bus’s ring could pass regulation ECE R66, and the pipe only increased 7.17% of the overall weight. This paper adopted computer simulation which used on equivalent approval method to do the rollover test on complete vehicle. Due to consider the welding failure, the result of this paper is close to the reality. This paper can provide a reference for the bus manufactory to do future manufacturing and design. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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