Advanced Materials Research Vols. 308-310

Abstract: Nowadays a general platform has played an important role in the product design process. As the traditional similarity measure used in module division is to the design stage in which the features and set are static, it is impossible to find the similar components in alterative design stages. For this reason, a new common platform design method on extension-distance is presented. According to build the relative function, the threshold used in the key module recognition is easy to generate. Then the tolerance-constraint function in the customized components division for the common platform generation. Then the adaptability measure is used to find the optimal case in the database. The measure has been used in the gasoline saw common platform design process.

Abstract: In order to improve the absorption properties of chitosan wound dressings, this paper used chloro-acetic acid to convert chitosan fibers into partially carboxymethylated chitosan fibers. Fibers with various degrees of carboxymethylation were prepared by controlling the ratio between the weight of fiber and chloro-acetic acid. Results showed that the carboxymethylated chitosan fibers can absorb a large amount of liquid into the fiber structure. When the degree of carboxymethylation is below 50%, the carboxymethylated chitosan fibers can absorb a large amount of liquid whilst maintaining its fibrous struture at the same time.

Abstract: Based on laser and capacitive sensor, a method of measuring deflectable angle is presented, and a noncontact angle measuring system is established. This system has the advantages of simple constitution, real-time, on-line measuring, non-contact and high precision. It can be widely used in engineering, especially in blade angle detection of knife and scissors.

Abstract: The thermal conductivity problem of functionally graded plate is studied under different temperature fields by a new concise BEM in this paper. At first, we convert the heat conduction differential equation of functionally graded materials (FGMs) to a homogeneous material thermal conductivity equation by using variable substitution, then the Galerkin boundary integral equation is reduced to be a system of linear equations. Finally we arrive at an internal temperature of objects, and plot the distribution graphics and effects of material parameters on temperature distribution. It proves that the new concise BEM is very effective.

Abstract: It’s very impending for our country and scientists to build a new polar scientific icebreaker in order to take the place of the scientific icebreaker “Snow Dragon”, which is not suitable for more and more scientific researches in the polar areas in future, because many latest technologies and equipments, which improve icebreaker performances and research abilities, have appeared in recent years. To ensure icebreakers break ice and sail normally in atrocious polar environment, propulsion systems must be analyzed and designed particularly. According to the relative classification rules, many propulsion systems for a new polar scientific icebreaker are analyzed and compared with each other carefully in the process of project designs. And with a view to the vessel specification and work assignments in the polar areas, Azipod units are selected as the optimal propulsion systems for the icebreaker at last.

Abstract: In order to study the influence of convex hull density on friction contact of bionic surface, we observed the 3-D structure of locust, tree frog and grasshopper with the 3-D microscope system, the experiments show that there convex hulls(diameters are 4um-6um)on the unsmoothed surface of feet pads; based on that structure the paper designs four kinds of unsmoothed bionic surfaces with different densities(center distances are 2R, 3R, 4R and 5R), the four contact models built by ANSYS are solved at the same loads and constraint condition, results indicate that the elastic deformation on top surface of convex hull is minimum (about 1.000mm) and the maximum (2.135 mm) appears on the midpoint of neighboring convex hulls, and the elastic deformation would increase with the decreasing of convex hulls’ density, big and small density would decrease the contact pressure also. We conclude bionic unsmoothed surface with appropriate density would put up satisfying contact performances and the surface3（center distances is 4R）we designed provides a good reference for bionic surface design and fabricating.

Abstract: The rule of full stress is the most direct and effective method of the optimal design for shape steel truss. The full stress optimal design study of shape steel truss is about the optimal design of the discrete variable, which is more difficult than that of the continuous variable. Through the section parameters in the table of the shape steel, the function of the section area and the inertial radius is created, the optimal design of the discrete variable is changed into the optimal design of the continuous variable and the computed efficiency of iteration is promoted. Lastly, the general program is studied. Through this program, the truss with different kind and different shape in various load case is designed automatically. The result shows that the computation efficiency and accuracy is increased greatly, the proposed method can be used in the optimal design of the large-scale truss and spatial truss widely.

Abstract: The generalized stress and strength distribution interference theory is introduced to establish the reliability model of torsion spring in multi-failure modes. Using it as constraint condition, the lightweight optimization model of torsion spring based on reliability constraint in multi-failure modes is presented. And then an optimization design for a given structure of torsion spring is made to use the theoretical model under operating conditions and the reliability constraint. The weight of the opti-mized torsion spring is lighter than that of non-optimization. This verified the validity of the opti-mization method. The optimization method may contribution to design of aerospace equipments which demand strictly in weight.

Abstract: A multi-level finite element analysis approach is introduced to investigate force-induced deformations in milling of overall thin-walled structures. This prediction algorithm takes into account the deformation of the workpiece in different points of the tool path. The machining conditions are modified at each analysis step when the cutting force and deformation achieve a local equilibrium. The effects of feed rates on the workpiece form deformation can be predicted using a theoretical workpiece model. In addition, this methodology can be used to compensate the machining error taking into account the predicted workpiece deformations.

Abstract: By way of mechanical properties test and microstructure observation，the effect of Urea on TiO₂ particles has been researched，it has showed that ER fluid activity of the particles were closely associated with urea content. When the mass ratio of Urea/Ti is 30%, The property of TiO₂/Urea particles ER fluid is the best .The microstructure observation of the ER fluids under DC electric field showed that the particles aggregated to form thicker and dense column structure when the mass ratio of Urea/Ti is 30%, while the column structure were broken down when excessive urea/Ti (>30%) was been added.