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You X.,Chongqing Institute of Engineering
Jinshu Rechuli/Heat Treatment of Metals | Year: 2014

Influence of vanadium on low temperature impact property and alloy ductile brittle transition temperature of construction steel were studied based on Q390. The results show that after adding V, the grain of the steel is fined, the dimple fracture surface become small and deep which improves the low temperature impact absorbing energy effectively, and reduce the ductile brittle transition temperature. But the addition of V should be about 0.05wt%, otherwise the effect of V will be weakened. Source

Che L.,Chongqing University | Che L.,Chongqing Institute of Engineering | Du L.,Chongqing University | Huang Y.,Chongqing University
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2015

According to restraints given by constant-length of links, the constrained equations are established, and the system of nonlinear equations is then obtained to solve the function generating synthesis problem of spherical four-bar linkages. Consequently, this system is transformed into a saddle-point programming problem. By considering the constraint on length coordination, transmission angle, and to avoid branch defect, the constrained optimization model is thus constructed to formulate the approximately function generating synthesis of spherical four-bar linkages, which can be solved by the differential evolution (DE) algorithm. The constraint violation, weakly and strongly infeasible solution are defined to guide the search process. According to these concepts, an improved feasibility rule is presented to handle constraints and a feasibility-rule-based DE (FRDE) algorithm is formed to approach constrained optimization problems. The FRDE algorithm is tested against four benchmark problems and the results indicate that the presented algorithm outperforms the compared ones in term of reliability and robustness. Orientating optimization synthesis of mechanisms, it is studied to develop an FRDE algorithm with repair strategies (FRRDE) which integrates the repair operators into the FRDE algorithm. Five real cases of synthesis are given to show that this model and approach is valid and feasible, and the proposed FRRDE algorithm performs better in term of final results than compared algorithms. ©2015 Journal of Mechanical Engineering. Source

Yang Z.,Chongqing University | Yang Z.,Chongqing Institute of Engineering | Liang S.,Chongqing University | Sun Y.,Chongqing University | Zhu Q.,National Institute of Technology,Oyama College
JVC/Journal of Vibration and Control | Year: 2016

It is well known that chaos phenomenon is harmful for a nonlinear mechanical vibration system. For a running vehicle, chaotic vibrations may lead to early damage to road and the component of vehicle or even bring physical injury to crew member. In this paper, we first studied the possibility of chaotic vibration of the four degree-of-freedom half vehicle model under consecutive speed control humps on the highway. Then, a direct variable feedback control is proposed to eliminate the influence of chaos on vehicle nonlinear vibrations and how to select proper control parameters is discussed. © The Author(s) 2014. Source

Hu J.-J.,Chongqing University | Zhang Y.,Chongqing Chuanyi Automation Co | Zhou T.,Chongqing Institute of Engineering
ICIC Express Letters | Year: 2015

Based on the pioneer work of Konishi et al., with consideration of the influence of the steady desired speed effect of the two vehicles in front on the traffic flow, a new feedback control car-following model is presented to suppress the traffic jam under open boundary condition. According to the control theory, the condition under which traffic jam can be suppressed is analyzed. Compared with the previous control models, the simulation results show that the stability performance of our model is better than those of the previous models, and it confirms the correctness of the theoretical analysis © 2015 ICIC International. Source

Li S.-H.,Chongqing Institute of Engineering | Wu X.-B.,Chongqing Institute of Engineering | Huang C.-F.,Chongqing Institute of Engineering | Wang H.-L.,Chongqing Medical University
Wuli Xuebao/Acta Physica Sinica | Year: 2014

In the numerical calculation, the projected entangled pair state (PEPS) algorithm is the most important tensor network algorithm for two-dimensional strongly correlated electron quantum lattice system. In this paper, the optimization of PEPS for two-dimensional quantum system is discussed. An optimization connection between how to update the PEPS tensor and how to calculate the physical observable is investigated, for the tensor network algorithm based on the PEPS representation, which can greatly improve the utilization of computing resources. In this case, optimized PEPS algorithm, as a powerful tool, can be used to study quantum phase transitions and quantum critical phenomena in the thermodynamic limit of the two-dimensional strongly correlated electron quantum lattice system. Of course, optimization of PEPS algorithm program has many other applications, such as adding U(1) and SO(2) symmetry in PEPS algorithm, etc. © 2014 Chinese Physical Society. Source

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