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Finite element analysis and fuzzy multi-objective optimization technique have been integrated to solve the die structure design of sheet metal forming by transforming fuzzy multi-objective problem into a normal optimization problem. A mathematical model of fuzzy optimization for bending die was established. A fuzzy goal set was constructed. The fuzziness of multi-objective functions and constraints were defined. The optimal solution and optimal constraint value of individual objective function in the feasible field were found using the genetic algorithms. An electronic part bending case shows that this approach is more effective and accurate than traditional finite element analysis method and the ‘trial and error’ procedure.

In the past 50 years, many long-span continuous stone arch bridges have been built in China. Analysis of mechanical performances and load capacities of long-span continuous stone arch bridges has important significances for the safety assessment of the similar bridges. 3D elastoplastic finite element method is employed to analyze ultimate bearing capacity of a three-span arch bridge with sandstone masonry in this paper. The characteristics of structural geometric and material nonlinearities and cracking and crushing of the masonry are taken into account. Compared with single-span arch bridge, both the coaction of spandrel structure and main arch and the influence of loading arrangements on ultimate bearing capacity is analyzed. The failure characteristics of the structure under the ultimate load are also introduced. The analysis results and conclusions can be referenced for the safety assessment of similar bridges.

In recent years, the internal combustion engine has been widely used through technological advances to improve its environmental performance. Mechanical and electrical integration of the engine turbocharging system is based on conventional turbocharging system to increase motor in parallel with the turbocharger and the corresponding reversible energy storage components, so that achieve by adjusting the energy input or output direction and the size of the motor to adjust the exhaust turbocharger operating point and the gas supply function. According to matching requirements of light vehicle diesel engine, the analysis model of exhaust gas energy is obtained through qualitative analysis of exhaust gas energy in turbocharged diesel engine.