Papers by Author: Cheng Shuang Zhang

Abstract: To attain the optimal shape of the robot arm with the minimum compliance and the suitable weight and lower the possibility of vibration, this paper applies the homogenization method to describe the topology optimization design of the wafer handling robot arm which modal analysis is carried out subsequently. We deduce and establish the mathematical model of the topology optimization based on the homogenization method and calculate it by ANSYS. The results suggested that the compliance and the weight were reduced. Then we calculated the modal analysis of the optimized and non-optimized robot arms, and it was found that the first sixth natural frequencies of the optimized robot arm all increased whereas the probability of the natural vibration declined. It is concluded that the topology optimization design of the wafer handling robot has been shown to be effective in improving the stability of the robot arm.

Abstract: Armos fiber (F-12 aramid fiber in paper) was provided with broad application foreground as reinforcement material for advanced composites in aviation and spaceflight field, due to its outstanding properties, such as high modulus, high strength, high temperature resistance, erosion resistance and so on. However, the exertion of property was still limited by slippery surface, low surface energy and weak interfacial adhesion performance. In this study, the effects of oxygen plasma treatment time on polar functional groups introduced onto the fiber surface, surface free energy and surface topographic images were discussed by X-ray photoelectron spectroscopy (XPS) analysis, dynamic contact angle analysis system (DCA) and atomic force microscopy (AFM), respectively. It was found that the content of oxygen element and polar functional groups on fiber surface were all increased obviously after oxygen plasma treatment. The content of oxygen element on surface for untreated F-12 aramid fiber was 11.13%, while it increased to 15.20% after oxygen plasma treatment for 10 min; The content of polar functional groups on surface for untreated F-12 aramid fiber was 28.14%, while it increased to 38.11% after oxygen plasma treatment for 10 min. The polar component (γp) of fiber surface energy increased sharply from 6.82 mN/m to 36.68 mN/m after 10 min plasma treatment, the total surface free energy was increased from 46.26 mN/m to 64.66 mN/m.The results indicated that oxygen plasma treatment had introduced a large amount of reactive functional groups onto the fiber surface, and these groups can form together as covalent bonding to improve the surface wettability and increase the surface energy of fibers. At the same time, oxygen plasma treatment was able to generate a mass of bulges and grooves on F-12 aramid fiber surface, which had an active effect on increasing the chemical bond and mechanical function between fiber and resin and enhancing the interfacial adhesion performance of composite. The fiber surface grooves had been increased with the time prolonging before 10 min while decreased after 10 min, the results maybe relate to partial organic on fiber surface melting. It had an adverse effect on the interfacial adhesion properties of composite. Therefore, the optimum plasma treatment time was between 5 min and 10 min.