Volume 1 Issue 1
Authors: Jia Liu; Yan Shi; Hong Zhang
Abstract: With the demand of lightweight vehicles becoming stronger and stronger, the joining of aluminum and steel is brought forward gradually. However, the brittle intermetallic compounds form easily during the welding process of steel and aluminum alloy, which makes it become a difficulty in the field of welding. In recent years, the laser technology has been adopted widely in the welding field of steel and aluminum alloy for its unique advantages. Authors collect some literatures through participating international cooperation, attending international conference and documents searching, and summarize the applications of laser technology in the research of steel-Al dissimilar metals welding. The purpose is to provide a reference for the researcher engaging in the joining of steel and aluminum and boost the applications of lasers in the research and production.
Keywords: Laser Technology; Dissimilar Metals; Welding; Aluminum Alloy; Steel
Authors: Yiin-Kuen Fuh; Li-Chih Lien
Abstract: In both conventional electrospinning and NFES (Near-Field Electrospinning) processes, the applied electrical field should be capable of generating forces with equivalent-or-greater-than local surface tension in order to deform and elongate the polymer droplet into a conical shape called a Taylor cone. Experimental results on controlled formation of multiple Taylor cones demonstrate consistent semi-cone angles between 68° to 72°, which are comparable to the original NFES process and irrespective to the number of Taylor cones. In addition, we also report a new method for selectively depositing nanofibers by taking advantage of field enhancement in MEMS (Micro-Electrical Mechanical System) structures and NFES technique. MEMS structure with pyramidal cross-section and hexagonal shapes is used to deposit nanofibers in micron meter range.
Keywords: Taylor Cone; Near-Field Electrospinning; Nanofiber; MEMS; Micro-Structure
Authors: Chung-Ping Chang; Ying-Yi Cheng; Li-Hon Shyu; Yuan-Jen Chang; Yung-Cheng Wang
Abstract: Due to the rapid growth of the high technology industries, the quality requirements of the components become more stringently. The most important property of the micro-relay is the resonant frequency. The Young’s modulus and residual stress can be calculated by the resonance frequency of the relay. In the fast development of the technological of the integrated circuits, the product dimensions have been miniaturized. It is difficult to measure objects with the line width of 600 nm. And the scanning detection can be artificially controlled and verified only. The main purpose of this study is to construct a novel Michelson interferometer which offers the automatic measurement and calculation, analysis and accumulating signal data, and the experiemental results show that the measuring range of frequencies less than 450 kHz and amplitude over 5 nm can be achieved by the proposed automatic measurment system.
Keywords: Michelson Interferometer; Nano-Order Vibration
Authors: Weizhi Wang
Abstract: After analysing applicable limitations of process capability index Cp and process performance index Pp, we put forward a new evaluation index, which can evaluate statistical stability in a production process, and identify abnormal influence factors. Based on probability and mathematical statistics basic theory, we analysed and proved application principle of the new index, and proved that the new index had objectivity in evaluation in theory. With grinding process sampling data, we verified the new index applicability. The new calculation is simple, and has quantitative criterion, the new index is useful in production site.
Keywords: Process Capability Index Cp; Process Performance Index Pp; Statistical Steady State; F Distribution
Authors: Yi-Ming Pan; Wen-Long Yao
Abstract: This study aims at exploring the job shop production scheduling optimization. A novel Petri nets and genetic algorithm (PNGA) is present. Using the job shop production of a mold factory as a case study, we examined the capability of the proposed PNGA method and compared its performance with the traditional Genetic Algorithm (GA) and Hybrid Taguchi-Genetic Algorithm (HTGA) methods. The programming software of MATLAB was employed to model the Petri nets in this study. Taguchi’s method was adopted to obtain the optimal experimental parameters. The optimal parameter settings were then programmed into the PNGA program. In conjunction with the Petri nets model, the process time was then estimated. The simulation results show that the average processing time of PNGA is about 287 (unit time). It is less than 289.55 of the GA and 288.8 of the HTGA. The standard deviation of processing time of PNGA is about 5.20. It is less than 6.0 of the GA and 5.88 of the HTGA. That is, the proposed Petri nets and genetic algorithm (PNGA) is able to provide a better job shop production scheduling optimization.
Keywords: Job Shop Production Scheduling; Genetic Algorithm; Hybrid Taguchi-Genetic Algorithm; Petri Nets
Authors: Yuan Li-ming; Guan Jin-kai; Yuan Li-peng
Abstract: Hydraulic angular vibration table is a kind of complex and non-linear system. Applying traditional controller to the angular vibration system, it is difficult to make the control performance to a high level. Aiming at the requirements of high frequency response and high accuracy for the random vibration system, this paper built up the dynamic model of Continuous Rotary Electro-hydraulic Servomotor controlled by valves, and proposed the adaptive friction compensation controller of continuous rotary electro-hydraulic servomotor based on the LuGre friction model for the electro-hydraulic servo angular vibration table. At the same time, the random vibration replication experiment was carried out by using the adaptive friction compensation composite iteration control algorithm based on the frequency response estimator with self-adapting filter. The results of experiment show that the frequency response estimator with self-adapting filter is accurate for random vibration replication control and the adaptive friction compensation controller is favorable to improve system’s frequency response.
Keywords: Adaptive Friction Compensation; Frequency Response Estimator; Random Vibration Iteration Control Algorithm