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Gao W.,Hunan University | Mo X.,Hunan University | Fu R.,Key Laboratory of Automotive Transportation Safety Technology | Sun G.,Hunan University | And 2 more authors.
Guti Lixue Xuebao/Acta Mechanica Solida Sinica | Year: 2012

Design variables and noise factors have some fluctuations during the process of crashworthiness design for the foam-filled tapered thin-walled structures. Conventional optimization design algorithms ignore the effect of uncertainty factors, which often causes the optimal objective function to go beyond constraints or the objective function to become very sensitive to the functions of the design variables, leading to the design failure. To address the issue, a novel robust optimization based on the experimental design method, Kriging metamodel technique, Monte Carlo method and 6σ method was presented and applied to the crashworthiness design for the foam filled tapered thin walled structures. The results showed that the crashworthiness of the thin-walled structure was improved, and the reliability and robust of the objective function was enhanced. Because the Kriging metamodel was called in the optimization process, the presented method has higher efficiency than the conventional method. Numerical example indicates that this method has a strong engineering practical application and can improve the product quantity significantly. Source

Fu R.,Key Laboratory of Automotive Transportation Safety Technology | Guo Y.,Key Laboratory of Automotive Transportation Safety Technology | Yuan W.,Key Laboratory of Automotive Transportation Safety Technology | Feng H.,Key Laboratory of Automotive Transportation Safety Technology | And 2 more authors.
Safety Science | Year: 2011

The traffic accident rate on descending roads on mountainous highways is quite high. To study the effects of vertical gradient and length of road on traffic accidents on continuous descending roads, data from 1413 traffic accidents over an 85.43 km section of road were collected. By taking parameters such as the gradients in accident sites, and taking the average gradient in Nkm (N= 1, 2, 3, 4, 5) just prior to the accident sites as the profile parameter, scatter diagrams were drawn to explore the effects of the profile parameters on the distribution of traffic accidents. Analysis of the exponential regression and correlation analysis between accident rates and profile parameters was carried out as well. The research results show that the accident rate increases with average vertical gradient exponentially; the differences between accident rate and different profile parameters are significant; the accident rate has a good exponential relationship with average gradients when a section has a 2 km or 3 km slope just prior to the accident sites i.e. the accident rate at a specific section on a continuous descending road is related to the average gradient in 2-3 km descending sections just prior to the accident site. The findings indicate that a steep gradient alone is not the reason for an accident, but we also have to take into consideration the presence of a "continuous long" descent prior to it. © 2010 Elsevier Ltd. Source

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