This paper proposes a multi-material topology optimization formulation for thermo-elastic structures considering coupled mechanical and uniform thermal loads. The ordered-SIMP multiple materials interpolation model is introduced, combined with examples considering structural volume minimization under stress constraints. The p-norm function with the adjusted coefficient was adopted to measure the global maximum stress. The adjoint variable method is presented to discuss the sensitivity of stress constraints, and the method of moving asymptotes (MMA) is utilized to update the design variables. The results demonstrate that clear topologies are obtained for complicated multiple material combinations with various temperature values. Meanwhile, the optimized configuration with stress constraints has clear sensitivity to uniform temperature variations. Therefore, the proposed model demonstrates the necessity of a thermo-elastic model influenced by temperature in optimization.
2 October 2012 in International Journal of Automotive Technology
The vehicle will generate an amount of current while the electric vehicle just starting to regeneratively brake. In order to avoid the impact of high current on the traction battery, a novel electrohydraulic hybrid electric vehicle has been proposed. The main power source is supplied by the electric drive system, and the hydraulic system performs the auxiliary drive system that fully exerts the advantages of the electric drive system and the hydraulic drive system. A proper regenerative braking control strategy is presented, and the control parameters are determined by the fuzzy optimization algorithm. The simulation analysis built the model through the united simulation of AMESim and MATLAB/Simulink. The results illustrated that the optimized control strategy can reduce battery consumption by 1.22% under NEDC-operating conditions.
To improve the energy recovery rate and increase the driving range of load‐isolated electric buses, a composite brake control strategy based on fuzzy logic optimization is proposed. Considering the influence of the battery SOC value and the braking intensity on the braking ratio, a fuzzy controller is designed for small and medium braking strengths to optimize the control strategy. The vehicle simulation model of the load‐isolated electric bus was built with the AVL CRUISE software platform. The AVL CRUISE‐Simulink cosimulation was carried out under the original control strategy and the optimized control strategy. The simulation results show that, under the premise of ensuring the stability of braking, the driving range of the vehicle with the optimized control strategy is increased by 7.74% and the energy recovery rate is increased by 11.05%.