Advanced Materials Research Vol. 505

Abstract: The main objective of the present investigation is to make a computational study of flow structure inside the engine cylinder in a DI diesel engine during the end of compression stroke at an engine speed of 1000 rev/min. The analysis has been carried out for four different piston configurations viz., flat piston, centre bowl on flat piston, inclined and inclined offset bowl piston. A polyhedral trimmed cell has been adopted for meshing the geometries using the code called STAR-CD Es-ice. The flow has been simulated by solving the governing equations of conservation of mass, momentum and energy using the SIMPLE algorithm. From this numerical prediction, the best possible combustion chamber configuration and the location of fuel injector on the cylinder head have been arrived.

Abstract: The work of this paper presents the use of MPSO which is an evolutionary optimizer. The work objective is finding the optimal shape of triangular slot in a tire tread block. The numbers of design parameters with triangular slot are 9. They are used to characterize size and position of the triangular slot in a tire tread block. The optimization methods are implemented to solve two objectives. First, the normal contact stress at contact patch region must be lowest and second, the friction contact stress at the same region must be highest. Therefore, the problem type is bi-objective optimization. The finite element analyses are simulated by modeling of tire tread block contacting to the friction surface with commercial finite element program (ANSYS). The models are simulated as compressing and sliding or braking situation. The tire tread block is modeled as hyperelastic material which used the three basic tests, i.e., uni-axial tensile test, planar shear test and equal bi-axial tensile test. The best fitted of hyperelastic material model for the work is Ogden Hyper Foam order 3th. The results of work are present as the mean of design parameters which are accepted for two objectives.

Abstract: Based on the rock pressure tunnel support present situation carries on the analysis, the laminated elastic beams of high support ability and impact resistance was designed.Therefore, through assumptions and establishment of mathematical model, and the application of viscoelastic beam dynamics equation, deformation and energy absorption of the laminated elastic beam elements,under the condition of rock burst, was deduced. According to the load - displacement characteristic curve, the coupling of laminated elastic beam elements and rockburst in coal mine roadway was analysed. This can provide a new method in the field of safety production of mining and roadway.

Abstract: As people paying more attention to the automotive safety performance, the car manufacturers bring steady improvement in the pedestrian protection of vehicle. This paper contains a new type of energy absorber used for lower leg-form impact by concept design method through Madymo (MAthematical DYnamic MOdel). Finally it is validated by full FE analysis. This new type of energy absorber can improve the performance of lower leg-form impact; also provide a design reference for vehicle's frontal system design.

Abstract: An antilock braking method based on sliding mode control (SMC) for electric vehicles (EVs) is proposed on the basis of antilock braking dynamics model, and hence an SMC controller of antilock braking system is designed. Aiming at the chattering of SMC, a method of parameter fuzzy optimization for exponential approach law is proposed, which can meet the requirements for small chattering, strong disturbance attenuation and fast convergence. In order to take full advantage of regenerative braking force, a method of braking force distribution between mechanical and electrical braking systems is elaborated. The simulations on the road with different friction coefficients show that the vehicle speed is in good agreement with the wheel speed during braking, and the slip ratio is kept within an optimal range. Adopting SMC based on fuzzy optimization, optimal slip ratio can be tracked fast and accurately. Furthermore, since the regenerative braking force is made full use of during braking, the energy recovery efficiency is high.

Abstract: In order to solve the problem that the performance of anti-whiplash seat did not satisfy the requirements of score, the seat is analyzed for the structure and simulation. It is found that there are several main factors which have great influence on it such as Head Restraint geometry position, Head Restraint and seat back stiffness, seat bracket stiffness and so on. With optimized and adjusted correlative parameter, the seat exerts itself completely with excellent performance of anti-whiplash and this performance of car will also meet target request.

Abstract: Combining the advantages of basic genetic algorithm and neural network, analyze and set up GA & NN genetic neural network, explore and study the algorithm. The efficiency and effectiveness of this hybrid training has been significantly improved comparing with the single genetic evolution or BP training method, its versatility is better. The model is applied to predict the deformation of shield tunnel excavation. According to the effects of measured influence factors under construction, it can make the appropriate forecast to the surface settlement which is better than the conventional regression model. It shows that neural networks in the ground during tunneling shield analysis and prediction of settlement is practical and adaptable.

Abstract: Current demands on renewable alternative fuel, biodiesel claims considerable significance. Biodiesel can be produced from any type of vegetable oils but yielding is determined by its free fatty acid (FFA) content. The alkaline-catalyzed esterification is not suitable for the unrefined vegetable oil which has high acid content. Hence, two-step esterification process is used to derive the kapok methyl ester due to its high FFA value. The biodiesel production in the two step process consists of acid-catalyzed pretreatment followed by an alkaline-catalyzed transesterificatin. In this study, experimental investigations are carried out in compression ignition engine to analyze the properties, performance and emissions characteristics of different blends of kapok methyl ester and compared with diesel. The exhaust gas temperature and specific fuel consumption are increased with increase of load and amount of biodiesel. The CO2 emission is slightly higher and NOx emission is about 22 percentage higher than that of the diesel at all the loads of engine. However, lower biodiesel blends showed reasonable efficiencies, lower value of smoke, CO and HC emissions.

Abstract: The paper illuminates the designed automatic weld control system. The RAC calibration arithmetic considering radial distortion is introduced, and according to the actual conditions of this weld system, the inchoate rapid calibration arithmetic is designed. Finally combined with the precision characteristic of the non-linear RAC calibration arithmetic and the concision characteristic of the inchoate rapid arithmetic, the improved automatic calibration arithmetic with six parameters is proposed, which achieves satisfied result.

Abstract: Semi-rigid layer is widely used as the base in China. However, the structure has resulted in many premature distresses in asphalt concrete layer. In order to overcome the problem, the composite base is introduced which is composed by both flexible and chemically stabilized material. The internal stresses are calculated by linear multilayer elastic theory and then, a comparison of the stresses of asphalt pavement with semi-rigid base and composite base is provided. The result shows that the composite base composed by all, consisting of the asphalt treated layer, graded crushed stone and cement treated layer is more suitable structure to resist cracking and the structure also has good adaptability to heavy load.