为保证汽车行车安全,前舱盖需满足刚度、模态和行人保护等要求。针对汽车前舱盖的轻量化设计需求,建立了铸铝一体化前舱盖有限元模型,分析了前舱盖的刚度、模态和行人保护性能,构建了RBF-Kriging混合近似模型并联合存档微遗传算法(archi...为保证汽车行车安全,前舱盖需满足刚度、模态和行人保护等要求。针对汽车前舱盖的轻量化设计需求,建立了铸铝一体化前舱盖有限元模型,分析了前舱盖的刚度、模态和行人保护性能,构建了RBF-Kriging混合近似模型并联合存档微遗传算法(archive based micro genetic algorithm,AMGA)对前舱盖进行多目标优化。针对多目标优化产生的Pareto解集,提出一种基于模糊层次分析-逼近理想解排序(fuzzy analytic hierarchy process-technique for order preference by similarity to ideal solution,FAHP-TOPSIS)法对Pareto非劣解进行综合性能排名,主客观相结合地选择出最优方案。结果表明,在满足性能要求的前提下,最优一体化前舱盖质量降低了32.14%,轻量化效果显著。展开更多
Cylinder-crown integrated hydraulic press （CCIHP） is a new press structure. The hemispherical hydraulic cylinder also functions as a main portion of crown, which has lower weight and higher section modulus compared ...Cylinder-crown integrated hydraulic press （CCIHP） is a new press structure. The hemispherical hydraulic cylinder also functions as a main portion of crown, which has lower weight and higher section modulus compared with the conventional hydraulic cylinder and press crown. As a result, the material strength capacity is better utilized. During the engineering design of cylinder-crown integrated structure, in order to increase the fatigue life, structural optimization on the basis of the adaptive macro genetic algorithms （AMGA） is first conducted to both reduce weight and decrease peak stress. It is shown that the magnitude of the maximum principal stress is decreased by 28.6%, and simukaneously the total weight is reduced by 4.4%. Subsequently, strain-controlled fatigue test is carried out, and the stress-strain hysteresis loops and cyclic hardening curve are obtained. Based on linear fit, the fatigue properties are calculated and used for the fatigue life prediction. It is shown that the predicted fatigue life is significantly increased from 157000 to 1070000 cycles after structural optimization. Finally, according to the optimization design, a 6300 kN CCIHP has been manufactured, and priority application has been also suggested.展开更多
文摘为保证汽车行车安全,前舱盖需满足刚度、模态和行人保护等要求。针对汽车前舱盖的轻量化设计需求,建立了铸铝一体化前舱盖有限元模型,分析了前舱盖的刚度、模态和行人保护性能,构建了RBF-Kriging混合近似模型并联合存档微遗传算法(archive based micro genetic algorithm,AMGA)对前舱盖进行多目标优化。针对多目标优化产生的Pareto解集,提出一种基于模糊层次分析-逼近理想解排序(fuzzy analytic hierarchy process-technique for order preference by similarity to ideal solution,FAHP-TOPSIS)法对Pareto非劣解进行综合性能排名,主客观相结合地选择出最优方案。结果表明,在满足性能要求的前提下,最优一体化前舱盖质量降低了32.14%,轻量化效果显著。
文摘Cylinder-crown integrated hydraulic press （CCIHP） is a new press structure. The hemispherical hydraulic cylinder also functions as a main portion of crown, which has lower weight and higher section modulus compared with the conventional hydraulic cylinder and press crown. As a result, the material strength capacity is better utilized. During the engineering design of cylinder-crown integrated structure, in order to increase the fatigue life, structural optimization on the basis of the adaptive macro genetic algorithms （AMGA） is first conducted to both reduce weight and decrease peak stress. It is shown that the magnitude of the maximum principal stress is decreased by 28.6%, and simukaneously the total weight is reduced by 4.4%. Subsequently, strain-controlled fatigue test is carried out, and the stress-strain hysteresis loops and cyclic hardening curve are obtained. Based on linear fit, the fatigue properties are calculated and used for the fatigue life prediction. It is shown that the predicted fatigue life is significantly increased from 157000 to 1070000 cycles after structural optimization. Finally, according to the optimization design, a 6300 kN CCIHP has been manufactured, and priority application has been also suggested.
