Papers by Keyword: Structural Parameter Optimization

Abstract: In order to help patients with wrist injuries to carry out recovery training, a simple and portable parallel 3-RSR wrist rehabilitation mechanism was introduced in order to achieve the expected therapeutic effect. Firstly, the parallel 3-RSR wrist rehabilitation mechanism is described. Taking the parallel mechanism as the research object, the degree of freedom is calculated and the pose is solved by analytical method, which verifies the rationality of the mechanism motion. Then, based on the boundary search method, the reachable workspace of the parallel wrist rehabilitation mechanism is analyzed, and the relevant workspace map is drawn. Finally, considering the reasonable optimization of the structural size of the workspace, the results show that the optimized reachable attitude workspace is significantly larger than the initial workspace. This study provides a theoretical reference for the ontology design of rehabilitation institutions.

Abstract: The static decoupling performance is closely related to the efficiency of the bionic elbow joint mechanism. The bionic elbow joint has good static decoupling and has high efficiency and carrying capacity. First, the movement structure and characteristics of the elbow joint are analyzed, a kind of bionic elbow joint is proposed, the position inverse solution is deduced, and force Jacobin matrix of the bionic elbow joint is obtained. Second, the static coupling performance evaluation index and the global static coupling performance index are established, the performance atlas are drawn. Thirdly, by use of the Monte Carlo method the structural parameters of the bionic elbow joint are optimized and selected based on the spatial model theory, and a novel the bionic elbow joint is designed based on parameters optimization, and the static decoupling is verified by the simulation experiment of the bionic elbow joint. The analysis results shows the static decoupling performance of the bionic elbow joint is symmetrical, and with the working space of the attitude output angle increases, the static decoupling decreases gradually. Structural parameters and have great influence on the global static decoupling performance. The structural parameters of is 90mm, is 70mm,and is 30mm, the bionic elbow joint has good static decoupling. This paper lays a foundation for further analysis and research of the bionic elbow joint.

Abstract: Logging while drilling (LWD) neutron instrument is a core equipment of the pulsed neutron logging technology, its anti-vibration performance has a direct impact on the measurement accuracy. For improving the anti-vibration performance, a reverse design method was proposed to avoid the resonance region due to increasing structural stiffness. The dynamic performance of the original instrument was analyzed, the weaknesses of its anti-vibration performance were determined and its topologies were improved. Moreover, the structural parameters of the instrument were optimized to raise the structural base frequency. The results show that the base frequency of the instrument increases high enough, the influence curves and surfaces of the base frequency with design variables provide a theoretical reference for the design of a LWD neutron instrument.

Abstract: A mine plans to exploit the low dip thin phosphate deposit by room-and-pillar mining. But a township highway is just above the orebody, and its distance is only 80m, in order to better control the ground pressure in stopes and ensure the operation security, the size of room and pillar must be reasonably designed to maintain the stability of stopes and surrounding rock. The 3D-σ numerical simulation method was applied to analyze the surrounding rock stability in different stope structure parameters. The results show that when holding the size of pointed prop unchanged, the surrounding rock stability would decline with the increase of room width and pillar spacing, for security, the mining plan, the pointed prop is 3×3 m, the stope width and pillar spacing is not more than 9 m, were considered to be one of the optimal. In addition, it is important to emphasize that if the mining depth exceeds 300m, some methods, such as decreasing the spacing of stope and pointed props or increasing the pillar size, need to be taken to avoid the stope instability caused by greater ground pressure.

Abstract: Vibration isolation structure of Siemens-Schottel-Propulsor (SSP) is analyzed and the parameters and optimization in vibration isolation structure is computed theoretically in this paper. The choice of parameters in vibration isolation structure is an optimization process, and it is subjected to many practical constraints. From the view of the force strength, the vibration isolation materials should be “hard” while from vibration reducing effect it should be “soft”. For the double-layer vibration reducing structure, in addition to meeting the requirement of deformation and strength, the obvious stiff difference should be arranged in structure to reduce vibration. The vibration isolation structure plays the role as a transfer functions, outputs different responses according to different excitation input. The results show that the characteristics of the exciting signals should be considered in the SSP vibration isolation structure’s design, it is important to select the vibration isolation for SSP cushion materials.

Abstract: The working principle of piezoelectric vibration energy harvester is described. A piezoelectric cantilever and mass composite structure is proposed to harvest vibration energy in resonance mode, and the mass is added on the edge of the cantilever to decrease the natural frequency of the whole structure. The finite element analysis was carried out on the composite structure using the ANSYS software. The displacement results were obtained by structural analysis, and the first order natural frequency was also obtained by modal analysis. Finally, the influence rules among the structural parameters, such as length and width of the cantilever, length and thickness of the mass and width of the PZT, and the natural frequency, piezoelectric output voltage are discussed in detail. Finally, the optimal structure of the harvester is obtained.

Abstract: This paper focuses on the structural optimization of chemical sensor support for food safety detection. The mechanical characteristic of chemical sensor support is influenced greatly by its structural parameters. Aiming at improving dynamic stiffness of the support, the modal analysis is implemented with the dynamic theory and the finite element analysis. And a group of rational structure parameters are determined through the optimum calculation. The validity simulation of the optimization is verified by the analyses of the random vibration and harmonic response. The results demonstrate that the performance of the support of the chemical sensor applied for the food detection is enhanced greatly by the presented optimization method here.