Advanced Materials Research Vols. 189-193

Abstract: A three dimensional thermo-mechanical model for FSW is presented. It's based on the model proposed by Alma H. Oliphant et al.[1] and Jacquin, D.et al.[2]. Velocity fields and initial plunge temperature profile are introduced in the steady state calculation of the temperature field during welding. And the non-adiabatic heat transfer conditions between the tool, the work piece, and the backing plate are also applied to the model. So a more accurate temperature will be got. It is anticipated that the model can be extended to optimize the FSW process parameters.

Abstract: The paper presents a turning method by using the magnetostrictive transducer as drive source, this method set up a self-made magnetostrictive tool-post on the CNC lathe. Theoretically, based on the theory analysis of piston skirt varying to oval cross section and middle-convex mold line, this paper expounds the reality of the magnetostrictive turning machining mechanism of middle-convex and varying surface. Experimental results show that this method can not only satisfy the requirements of design, but also simplify workpiece process, establishing theoretical and experimental basis for magnetostrictive material applied to the piston skirt middle-convex and varying surface truning machining.

Abstract: Based on chemical composition of the corrosion product, a mathematical model was developed to predict the extent of the pillowing deformation of lap joints of LY12CZ in term of thickness inside the joint. The model can offer the capability for predicting the extent of corrosion within the joint in terms of thickness loss at the internal surfaces of the skins from the amplitude of the pillowing of the outer skin. Three-dimensional finite element model of a bolted joint have been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with the mathematical model. The results show that corrosion pillowing can significantly increase the stress in a lap joint for material loss below the detection limit of current nondestructive inspection techniques, thus increasing the risk of premature cracking. In addition, the analyses show that the locations of maximum stress of lap joint will change with the material loss increases. Simulating the effect of corrosion on lap joint only by reducing the panel thickness will result in neoconservative life estimates if corrosion pillowing is ignored.

Abstract: Hot stamping represents an innovative manufacturing process for forming of advanced high strength steels, implying a sheet at austenite temperature being rapidly cooled down and formed into a die at the same time (quenching). This affords the opportunity to manufacture components with complex geometric shapes, high strength and a minimum of springback which currently find applications as crash relevant components in the automotive industry. With regard to the numerical modeling of the process, the knowledge of thermal and thermo-mechanical properties of the material is required. The material model under hot stamping condition of advanced high strength steel should be set up. The Finite Element Analysis is an essential precondition for a good process design including all process parameters. This paper presents the finite element simulation of a hot stamping process and describes a number of procedures for the simulation of hot stamping. In addition, the development direction is pointed out at the end of this paper.

Abstract: Regarding the lack of interactivity for Virtual Knee Arthroscopic Surgery, which leads less immersion in simulated surgery, a new advanced interactive device in Virtual Knee Arthroscopic Surgery based on displacement sensor and Data acquisition card was developed. Based on study of degree of freedom on Knee Arthroscopic Surgery, a new interactive device on simulating real surgery was proposed. This device simplifies true operation for four degrees of freedom. Each displacement sensor captures information from one degree of freedom, then sends the information to the data acquisition card to carry out analysis and treatment for the purpose of synchronization on the computer, then realize realistic simulation of surgical procedures. The creative design of the interactive device makes it possible to flexibly adjust the location and angle of simulated scalpel and endoscope according to different operator and reach the requirement of immersion of virtual reality.

Abstract: Optimal fixture involves fixture layout and clamping force determination. It is critical to ensure the machining accuracy of workpiece. In this paper, the clamping process is analyzed with the consideration of cutting forces and frictions using the finite element method. Then the fixture layout and clamping force are optimized by minimizing the workpiece deformation via a Genetic Algorithm (GA). Subsequently, linear programming method is used to estimate the stability of workpiece. It is shown through an example that the proposed method is proved to be efficient. The optimization result is not only far superior to the experiential one, but also the total optimization time can be reduced significantly.

Abstract: An elastic-plastic finite element study on the contact of a railway wheel and a high manganese steel crossing is reported. The contact model of the wheel/crossing/ties is established to simulate the interactions between the wheel and crossing and between the crossing and ties. The effects of train speed and axle load on the von Mises stress and the equivalent plastic strain of the high manganese steel crossing are discussed.

Abstract: The topic is according to the laminated-speed Gel-type technology to design all the parts of the RP machine, establish the 3D model，assemble the parts together by Pro/E，set the parameters, such as motor parameters and so on, and finally achieve the 3D simulation of the device. The real movement process can be seen by the simulation. It is also available to analyze the rationality of the design according to the simulation. Besides, ANSYS is used to analyze the distortion of the workbench, and a certain degree of distortion is found to have affected the precision of the ceramic parts process at some extent. Based on this, the structure is changed and analyzed again, and then all the requirements have been met. At last, a control system is designed in accordance with requirements of the rapid prototyping machine. Thus the whole design of the machine is completed.

Abstract: In this paper, according to the domestic construction machinery market，bulldozers，the representative machinery assembling with hydraulic lifts make mechanical, electrical, hydraulic innovative design. AMESim software will use for its modeling and simulation. AMESim simulation results show that the new design of the hydraulic lift is more stability and synchronization than the traditional one.

Abstract: A series of numerical meso-mechanical models for different kinds of particle (include spherical, cylindrical and discal) reinforced composites are developed to investigate the effect of microstructural parameters on the elastic properties of composites. In these models, an effective interface concept is adopted. Finite element models with prescribed and random parameters are automatically generated in ABAQUS PDE (Python Development Environment). In the simulative investigations, it is observed that the degree of particle clustering and particle’s shape have strong effects on the elastic mechanical properties of composites.