Advanced Materials Research Vols. 602-604

Abstract: The need to create lighter vehicles to aid in reducing emissions and increase fuel efficiency has become increasingly important in recent years. Self-pierce riveting (SPR) has drawn more attention as it can join some advanced materials that are dissimilar and hard to weld. In present study, the SPR process has been numerically simulated using the commercial finite element (FE) software LS-Dyna. For validating the numerical simulation of the SPR process, experimental tests on specimens made of aluminium alloy have been carried out. The online window monitoring technique was used in the tests for evaluating the quality of SPR joints. Good agreements between the simulations and the tests have been found, both with respect to the force-travel curves as well as the deformed shape on the cross-section of SPR joint.

Abstract: The heat flow distribution in a simplified 3-D vehicle cabin is predicted when parking in the summer sunshine by using the CFD analysis software. The nature convection and radiation heat transfer from environment to cabin are considered in this simulation. The distribution of transient temperature and velocity at the central and horizontal plane are analyzed respectively. It is shown that the temperature increases by time and there is little temperature difference in the cabin. The highest value is located at the front and both sides cabin after two minutes. The air is essentially stagnant with low velocity and the central compartment has much lower velocity than other regions.

Abstract: The energy regenerative and feedback friction integrated braking system for electric vehicles is projected, and the integrated system dynamic model is set up. Offer the EBD control strategy on nonuniformity roads based on ABS system. Based on the Matlab/Simulink, establish the dynamic simulation system of integrated braking system and EBD control for the electric vehicles; Based on the Chery A3 car, simulate and analyze the integrated braking system EBD control performances on the condition of driving straight on nonuniformity roads. The study results indicate that the energy regenerative and feedback friction integrated braking system for electric vehicles has good EBD performance, and has high regenerative braking efficiency, braking performance and braking stability.

Abstract: A novel Chaotic Improved Cat Swarm Algorithm (CCSA) is presented for global optimization. The CSA is a new meta-heuristic optimization developed based on imitating the natural behavior of cats and composed of two sub-models: tracing mode and seeking mode, which model upon the behaviors of cats. Here different chaotic maps are utilized to improve the seeking mode step of the algorithm. Seven different chaotic maps are investigated and the Logistic and Sinusoidal maps are found as the best choices. Comparing the new algorithm with the CSA method demonstrates the superiority of the CCSA for the benchmark functions.

Abstract: A novel Chaotic Grenade Explosion Algorithm (CGEA) is presented for global optimization. The GEA is a new meta-heuristic optimization developed based on the observation of a grenade explosion, in which the thrown pieces of shrapnel destruct the objects near the explosion location. Here different chaotic maps are utilized to improve solution search equation of the algorithm. Seven different chaotic maps are investigated. Comparing the new algorithm with the GEA demonstrates the superiority of the CGEA for the benchmark functions.

Abstract: Based on the concepts of homotopy, a novel cat swarm algorithm, called a homotopy-inspired cat swarm algorithm (HCSA),is proposed to deal with the problem of global optimization. Proceeding from dependent variables of optimized function,it traces a path from the solution of an easy problem to the solution of the given one by use of a homotopy--|a continuous transformation from the easy problem to the given one.This novel strategy enables the cat swarm algorithm (CSA) to improve the search efficiency. Theoretical analysis proves that HCSA converges to the global optimum. Experimenting with a wide range of benchmark functions, we show that the proposed new version of CSA, with the continuous transformation, performs better, or at least comparably, to classic CSA.

Abstract: Based on the concepts of homotopy, a novel Grenade Explosion Algorithm, called a homotopy-inspired Grenade Explosion Algorithm (HGEA),is proposed to deal with the problem of global optimization. Proceeding from dependent variables of optimized function,it traces a path from the solution of an easy problem to the solution of the given problem by use of a homotopy--|a continuous transformation from the easy problem to the given one.This novel strategy enables the Grenade Explosion Algorithm (GEA) to improve the search efficiency. Theoretical analysis proves that HGEA converges to the global optimum. Experimenting with a wide range of benchmark functions, we show that the proposed new version of GEA, with the continuous transformation, performs better, or at least comparably, to classic GEA.

Abstract: The cross-sectional shape of profiled fibers has made obvious influence on fibers physical properties. The fiber profiled factor is an index used to estimate the deformation degree of profiled fibers. Based on the equations of melt-spinning dynamics and deformation, a numerical simulation program for calculating the fiber profiled factor along the spinning path was developed. A numerical simulation for calculating the fiber profiled factor along the spinning path of trilobal fibers in the PET melt spinning was performed. The simulation result graph of the fiber profiled factor along the spinning path is close to the final average fiber profiled factor measured in the spinning experiment under the same condition.

Abstract: The nitrogen implanted profile in aluminum generated by 60keV N₂⁺ bombardment is simulated numerically by the Stopping and Range of Ions in Matter (SRIM) program and is fitted analytically by the Schulz-Wittmaack expression. Taking the SRIM simulated profile as true concentration-depth profile of implanted nitrogen in aluminum matrix, the corresponding measured AES depth profiling data of implanted nitrogen are well fitted by the Mixing-Roughness-Information (MRI) model.

Abstract: The physical modeling, which developed rapidly and applied widely, has been widely accepted as an effective method to study the deformation mechanism and the process of tectonic evolution. Granular materials, which were widely used in the physics modeling, were commonly used to analog the deformation of the upper crust. Some attribute of different materials play an important role in the physical modeling. Many previous studies suggested that the granule roundness determined the angle of internal friction. The detail of their impact, however, is still obscure and poorly understood. Microspheres, beach quartz sand, and artificial quartz sand are used to investigate the impact of the roundness on physical modeling in this case study, using three models with some similar parameters. The present study shows that the microsphere with perfect roundness made it easy to roll, leading to the profile of fold-thrust belt round. Some deformation details are difficult to decode, and the strain distribution was dispersed. The model with artificial quartz sand uplifted highest, due to the angular roundness and the granule are difficult to move. The strain was most concentrated, suggesting significant discrepancy of strain value among different part of the deformation area. Beach quartz sand with appropriate roundness, however, showed the medium performance what we expect in structure physics modeling.