Applied Mechanics and Materials Vols. 249-250

Abstract: The knowledge and principles of air conditioning as well as numerical analyses and experiments are applied to obtain the various defog guides depending on extreme wet-conditions and the various outside air temperatures in all seasons. The defog guides can be listed as a leaflet to let the drivers know how to operate their air-conditioning control panel properly to defog the windshield with suitable air to obtain the safe and comfortable driving.

Abstract: Five-axis machine tool with two additional rotary axes has been widely used in defense, aerospace and the consumer industries, and is an important process of precision manufacturing. Traditional five-axis program depends on the machine tool’s configuration and machining setting. This leads to inconvenience of reprogramming five-axis NC code for the end users. This paper proposes a cutting point control algorithm for five-axis machining. Although the commercial advanced controllers provide this function, they are very expensive and restricted to export. The developed algorithm can be embedded to the PC-based controller so that the specific cutter location data can be transformed and employed easily for different cutting tools. Verification using VERICUT solid cutting simulation software demonstrated the correctness of the generated cutter location data.

Abstract: In the formation process of lithium-ion battery, the clamping force of the electrode tab-clamp is a very important factor for lithium-ion battery charge-discharge performance. Different from the traditional spring type tab-clamp, this paper proposes a leaf-spring type tab-clamp, that could produce the deformation of leaf-spring by the micro-motion of an actuating cylinder to provide a controllable clamping force of the tab-clamp upon the electrodes of lithium-ion battery. It is verified that the leaf-spring type structure is available and feasible through finite element analysis (FEA). According to the data from FEA, the relational expression between the clamping force and the micro-motion of the actuating cylinder is drawn out, and an impact analysis about design parameters to the clamping force is accomplished and some useful results are got. The study of this paper is helpful to guide mechanical design of the electrode tab-clamp for lithium-ion battery charging and discharging and to improve its mechanical performance.

Abstract: Brakes are machine elements that absorb kinetic energy in the process of slowing down or stopping a moving part. Brake capacity depends upon the unit pressure between the braking surfaces, the coefficient of friction, and the ability of the brake to dissipate heat equivalent to the energy being absorbed. In braking system, drum brake is used mostly for automotive application. During the braking process, the forces and pressures in a drum brake are difficult to determine because of the manner in which the shoe contacts the drum. Finite Element analysis has been used to predict interface temperatures and heat flows and the results have been compared with experimental measurements made using fine thermocouples. Good agreement has been achieved, showing that the proportion of heat which flows into the friction material varies with time and temperature.

Abstract: According to the structural characteristics of the controller and micro-groove heat sink technique, a new cooling system was designed for high power control unit of electric vehicles. And an experimental comparison on the radiating effect of forced air cooling, micro capillary groove radiator and their combination was then carried out. The experimental results showed that when compared with air-cooling method, the higher the power is, the more significant the heat dissipation effect is. The air cooling unit alone cannot meet cooling requirements when the heating power reaches 30 watts, with temperature exceeding the allowable ceiling for power devices. The strong heat removal ability of micro capillary groove radiator has a better effect for diminishing local overheating of IGBT, and it’s more applicable to cooling conditions of large heat flux.

Abstract: Operating characteristic of an air conditioning system for vehicle is dynamic and anomalous. Due to the dynamic behavior of the system, the performance measurement should be taken in account in many different kind of environmental condition with various thermodynamic variables. One of the driving conditions of the system, rotating speed of the compressor for air conditioning is the most important factor consideration that is directly connected to the vehicle engine through clutch and belt. The engine was simulated with 18.5KW class AC motor to drive the compressor. Two environmental chambers are built in this study to simulate operation condition of the system.

Abstract: On-line quality assessment becomes one of the most critical requirements for improving the efficiency of automatic resistance spot welding (RSW) processes. Accurate and efficient model to perform non-destructive quality estimation is an essential part of the assessment. Besides the usual welding parameters, various measured variables have been considered for quality estimation in RSW. Among these variables, dynamic resistance gives a relative clear picture of the welding nugget formation and presents a significant correlation withseveral RSW quality indicators. This paper presents a structuredand comprehensiveapproach developed to design an effective dynamic resistancebased model for on-line quality estimation in RSW. The proposed approach examines welding parameters and conditions known to have an influence on weld quality, and builds a quality estimation model step by step. The modeling procedure begins by examining, through a structured experimental design, the relationships between welding parameters, typical characteristics of the dynamic resistance curves and multiple welding quality indicators. Using these results and various statistical tools, different integrated quality estimation models combining an assortment of dynamic resistance attributes are developed and evaluated. The results demonstrate that the proposed approach can lead to a consistentmodel able to accurately and reliably provide an appropriate estimationof the weld quality under variable welding conditions.

Abstract: This paper, on analyses of the shortages of the traditional rapier loom weft insertion system such as unalterable motion rules and high machining accuracy requirements, introduces a new electric weft insertion method to the modern high-speed rapier loom, which converts single-direction rotation of a motor to linear reciprocation of a rapier with help of the spatial linkage. The new method can satisfy different weft insertion requirements by controlling the speed of the motor rotation, so that it greatly improves the weaving adaptivity of the loom for different wefts. The test results show that this new controlling method not only meets the technical requirements, enabling the gripper head to move without rigid and flexible impact, but also has good high-speed motion characteristics, in line with the requirements of high-speed weft insertion.

Abstract: We propose the first time combining the merit of scanning and immersion lithography to fabricate 3D microstructure in this study. Via applying a matching liquid to reduce the diffraction error, the gap between the mask/resist becomes more tolerable. In addition, the liquid also act as a lubricant and a buffer for smooth movement of the mask/substrate. These advantages will benefit the performance of scanning lithography technique. The experimental results show that the large-area, 3D microstructure with excellent surface quality (Ravg<10 nm) can be successively fabricated based on this method. Besides, 3D microstructures with various geometries and functionalities can be generated by altering the shape of the mask pattern, or changing the scanning directions. The proposed SIL technique seems to be a promising way for fabricating 3D microstructure for optical applications.

Abstract: For point-based image registration, transformations using radial basis functions on scattered points cause problems with topology-preservation. We propose here a topology-preserving transformation based on expansions of radial basis functions. By analyzing the non-preserving transformation given by the corresponding control points, this method computes the main shifting directions of topology non-preserving regions on deformed surfaces. It then determines the control points leading to the topology non-preservation results. Next, it adaptively relaxes these control points based on the spatial relationships of points, and adjusts the transformation function coefficients using relaxation parameters to construct the topology-preserving transformation. We provide here the method for selecting the control points that cause the topology non-preservation results and estimate the optimal relaxation parameters based on the shifting model of the control points. Experimental results on random point sets, artificial images and medical images show that this method is feasible and practicable.