Applied Mechanics and Materials Vols. 215-216

Abstract: Based on the platform of Visual Basic6.0, Visual FoxPro6.0 and Visual LISP, the optimal design system is developed by establishing mathematical model for optimization design of ZLZ/ZLY reducer and using integer optimal method and visual combination software development technology. The system consists of several exe executable programs and lsp programs. Under the control of internal interface program, the system can realize multi-objective integer optimization design and gear parts drawing.

Abstract: This paper introduces basic working principle of multi-cones synchronizer. Analyzes process of multi-cones synchronizer’s academic calculate and parameters calculate. And makes practice case of multi-cones synchronizer compute and analysis.

Abstract: A three-dimensional discrete element method analytic model of the corn seed metering device with combination inner-cell was established based on its 3D CAD model, and the three-dimensional particle model of corn seeds was built by using the method of combination spherical particle. The working process of the corn seed metering device was simulated and analyzed by self-developed three-dimensional CAE software. It was observed that the simulative results of the seeding performance, clearing angles and dropping angles of the corn seeds well agreed with the bench test results. A novel method for studying and designing of the corn seed metering device was put forward.

Abstract: Improvement of Weight capacity and weight-bearing exercise endurance in human are the main purpose of Portable Exoskeleton. The object of study is the Exoskeletons mechanical structure and through it to improve the structure bearing capacity. Firstly, this study takes the data of Chinese adult body size as the related parameters in ergonomics of Exoskeleton. Also the ergonomics parameters of pivotal bearing parts such as hip, thighs and legs will be confirmed according to the 50 percentage data of the data of Chinese adult body size. Based on it, 3D model of Portable Exoskeleton have been established by using Solidworks software and fast assembly of Exoskeleton’s parts have been accomplished. At the same time 3D Model have been conversed the x_t format and to be guided into the ANSYS software. A finite element based strength analysis of the mechanical structure of the external skeletal is then achieved with the load being 800N and the operating condition being one-leg standing. The numerical results show that key parts of the external skeletal meet the requirements. The maximum stress value is 127Mpa by ignoring the stress concentration phenomenon, confirming the reasonability of the structure design. Nevertheless, stress value on exoskeleton joints exceeds the material strength, some suggestions are then proposed on joint design.

Abstract: In allusion to the actual working condition of the articulated steering mechanism of the all-terrain vehicle which is in normal running while steering, the target in this paper is to optimize the positions of link joints on the model structures based on the application and motion state of mathematical modeling on the multi-body kinetic software Recurdyn, analyzing the motion and force of the key joints, and to do the structural adjustment on the optimal positions of two link joints. The optimization results indicate that the revolving speed and force are within the allowed limits and guaranteed that the turn radius would be the maximum and the force would be the minimum within the limits.

Abstract: Selective assembly is a method of obtaining high-precision assemblies from relatively low-precision components. In selective assembly, the mating parts are manufactured with wide tolerances. It is impossible that the number of components in the selective group will be the same, and a large number of surplus parts exist according to the difference in the standard deviations of the mating parts. A method with new grouping method and chromosome structure is proposed to minimize surplus parts by using genetic algorithm.

Abstract: A virtual prototype model has been established by using ADAMS and based on which the simulation of the main alignment parameters of vehicles with air suspension system has been analyzed. Focus on the unreasonable parameters that are off design, after confirming the design variable, the optimization has been done. According to the simulation and structure optimization, compared with un-optimized air suspension, the sideslip offset has reduced by 60.6%, which effectively achieve the target for structure optimization.

Abstract: Based on the parallel stable platform of 6-UPS, Jacobi matrix condition number and driving force of six rods are respectively identified as kinematics evaluation index and dynamics evaluation index of the parallel stable platform. By using physical programming preference functions the comprehensive preference function are constructed. Thus, a multi-objective optimization problem is formulated as a single objective optimization problem. Structural parameters with best working performance are computed by the genetic algorithm. Simulation results in Matlab show that the performance of optimization platform has been improved.

Abstract: For hard rocks whose protodyakonov scale of hardness f are greater than 8, research on the optimization design of cutting head of cantilever roadheader. Optimization model of the cutting head was established, in this model, the objective function was established based on dust mount, energy consumption and production efficiency. The design variables contain cutting head structural and kinetic parameters, the constraints are determined in accordance with working condition and practical experience. Cutting head parameters are optimized with parameters change related to rock strength, using genetic algorithm in Matlab7.0. A variety of cutting parameters optimization results related to rock strength are of great significance for the structural design of the cutting head and selection of kinetic parameters.

Abstract: On the basis of the traditional assemble method of components modular fixture, the establishment of a component-based modular fixture design method was proposed in the paper. First of all, the concept of modular fixture components was put forward, and then the components according to different functions were classified, and the relationship table between the components and elements were established. At last of this paper, the application of this method was introduced through an instance. While designing fixture for part family, this method can utmost save design time and minimize the quantity of disassembling of combined fixture element, reduce the wear and tear of components, and shortening the time of manufacturing.