Dynamic Optimization Design of a Warship’s Gearbox Based on FEM

2011 ◽  
Vol 86 ◽  
pp. 662-665
Author(s):  
Yan Hua Xue ◽  
Xiao Hong Li ◽  
Zhi Guang Wang ◽  
Jie Song

The transmission system of warship’s gearbox is increasingly developing in the direction of high-speed, high-efficiency, heavy-load and light-weight, and the requirements of vibration are increasing as well. The gearbox designed according to static standard often has various problems of instability and vibration which greatly weaken the behaviors of gearbox and influence the invisibility performance of warship seriously. To improve the vibration characteristics of gearbox, vibration modal analysis of a warship’s gearbox is studied based on FEM. In order to avoid resonance in transmission, double-frequency dynamic optimization design of a gearbox is studied and discussed. The method and conclusions can be used as a reference of design of warship’s gearbox.

2012 ◽  
Vol 184-185 ◽  
pp. 356-359
Author(s):  
Jiang Miao Yi ◽  
Dong Qiang Gao ◽  
Fei Zhang ◽  
Huan Lin

The finite element model of worktable system is created and modal analysis is made with ANSYS Workbench by taking DVG850 high-speed vertical machining center worktable system for example. We make modal analysis of single-screw strength general reinforcement worktable system and get the natural frequency and the vibration mode.Then in order to improve the system's natural frequency, the scheme of dual-screw worktable system is put forward. Also natural frequency and vibration mode is got. Finally, it is proved that the performance of dual-screw worktable system is significantly better than the single-screw one. This provides a reliable reference for further study on dynamic analysis of worktable system.


2011 ◽  
Vol 230-232 ◽  
pp. 916-919
Author(s):  
Chang Xian Cheng

By analyzing various kinds of gripper systems of different sheet-fed offset presses, the under-table swing-arm system, with a fixed axis, has the advantages of meeting high-speed press running requirement, keeping longer dwell time of printing sheets, helping improve print registration, and hence in favor of assuring HIFI print quality while having high press output. The dynamic optimization design of the under-table swing-arm system is vital to the higher performance of the system on the state of the art press machines. Through dynamic analysis of the gripper system, the way of dynamic optimization design and its correspondent formulas are derived in this paper.


2012 ◽  
Vol 201-202 ◽  
pp. 1071-1075
Author(s):  
Shu Hua Zheng ◽  
Wen Fei Peng ◽  
Xue Dao Shu

High-speed and heavy-load are the targets to pursue over a long period of time in high-speed transportation. The key to solve this problem is making the components lightweight. Particularly, the hollow shaft is a new type of lightweight construction. This article explains systematically the current situation and the defects of forming technique for the hollow shafts. The solid shafts formed by Multi-Wedge Cross Wedge Rolling (MCWR) and the hollow shafts by Cross Wedge Rolling(CWR) are researched, and the key problems of hollow shafts formed in MCWR to solve emphatically are pointed out. At the same time, we obtain that MCWR will be the main technology in forming long shafts. The results in this paper provide a new direction for the hollow shafts to form in a high efficiency, energy saving and material saving method.


2013 ◽  
Vol 561 ◽  
pp. 496-500
Author(s):  
De Gong Chang ◽  
Hong Yun Dou ◽  
Fu Qin Yang ◽  
Rong Zong

According to the working principle and structural characteristics of cylinder mechanism, the simplified model is built by the Pro/E software. Then we carry on the modal analysis for cylinder mechanism combined with ANSYS Workbench [1], and obtain the natural frequency and mode shapes of all steps. It provides the basis for optimization design and safety evaluation of cylinder mechanism. Finally, we study the influence of bearing stiffness on the critical speed, which provides the basis for the research of high-speed cylinder.


2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Ying He ◽  
Jiangping Mei ◽  
Jiawei Zang ◽  
Shenglong Xie ◽  
Fan Zhang

End effector mounting bracket is an important load bearing part of high speed and heavy load palletizing robot, which is located at the most distant point in robot rotation radius and frequently works in complex conditions such as start-stop, switch direction, and acceleration and deceleration motion; therefore, optimizing design for its structure is beneficial to improve the dynamic performance of robotic system and reduce energy consumption. Firstly, finite element model of end effector mounting bracket was established, and its accuracy was verified by contrastive analysis of modal test result and finite element model. Secondly, through modal analysis, vibration response test, frequency response analysis, and the static analysis, taking inertia into account, the mass is minimized, the maximal stress is minimized, the maximal deformation is minimized, and the first natural frequency is maximized as the optimization objectives are determined; the design variables were selected by sensitivity analysis, taking their value range as the constraint conditions; approximation models of objective functions were established by the Box-Behnken design and the response surface methodology, and their reliability was validated; to determine weighting factor of each optimization objective, an analytic hierarchy process based on finite element analysis (FEA + AHP) method was put forward to improve the objectivity of comparison matrix; subsequently, the multicriteria optimization mathematical model was established by the methods mentioned above. Thirdly, the multicriteria optimization problem was solved by the NSGA-II algorithms and optimization results were obtained. Finally, the contrastive analysis results between optimized model and initial model showed that, in the case of the maximum stress and deformation within allowable values range, the mass reduction was 17.8%; meanwhile, the first natural frequency was increased, and vibration response characteristics of the entire structure were improved significantly. The validity of this optimization design method was verified.


2013 ◽  
Vol 712-715 ◽  
pp. 1050-1053 ◽  
Author(s):  
Xiao Kai Mu ◽  
Yu Guang Li ◽  
Dian Hua Chen ◽  
Cheng Chao Li

The research is to solve nonlinear constrained optimization problems by the method of sequence quadratic programming (SQP) in MATLAB optimization toolbox and mathematical programming theory. This paper taking the high strength of WN gears drive as design target and the WN gears drive optimization design model of actual project is put forward by the concrete examples which are widely used in modern machine of the high speed and heavy load WN gears drive. Using the optimization design model to analyze the relationship about gear drive parameters on contact and bending fatigue strength. This research adopts the formula fitting design method not only improved design efficiency but also provided application foundation for CAD design of WN gears driving.


Author(s):  
Pekka Ro¨ytta¨ ◽  
Juha Honkatukia ◽  
Teemu Turunen-Saaresti

A centrifugal high-speed compressor is an effective light weight option to power a refrigeration cycle for air conditioning purposes. Perhaps the most important decision in design is the working fluid selection. Modern high-speed technology makes it possible for the refrigeration compressor to be completely oil free, which considerably broadens the scale of possible working fluids. Furthermore, many traditional fluids have become banned and the industry standard R134a might face the same faith in some European countries because of its relatively high global warming potential. In this study eleven different fluids were studied and compared and R22 was used as a reference. It was found that there are many potential fluids for centrifugal compressors that provide better efficiencies than the most common fluids in use today. The purpose of this study is to initially screen a larger set of candidate fluids for more accurate estimation later on. The fluids are evaluated by the efficiency of the cycle, but also mechanical feasibility and dimensions are considered as light weight of the machinery was an important criterion in design process. The comparison was made with constant evaporation and condensation temperature and fixed cooling power for all the fluids. In selection of the working fluid the safety factors often play a dominant role which was also shortly considered. In our study we found out that for a residential HVAC size cooling cycle there are environmentally friendly fluids with high efficiency leading to feasible mechanical designs with centrifugal compressors.


2005 ◽  
Vol 291-292 ◽  
pp. 325-330 ◽  
Author(s):  
Yu Hou Wu ◽  
Song Hua Li ◽  
Ke Zhang

In resent years, ceramic balls have been applied into precision bearings and other parts far and wide because of its advantages in light weight, high hardness, abrasive resistance, high-temperature resistance, corrosion resistance, little heat expansion coefficient and so on. The high-precision ceramic balls are machined by lapping usually, and the method of lapping has an important influence on the machining precision and efficiency of ceramic balls. In order to improve the precision and efficiency of ceramic ball machining, in the paper, a new cone lapping method is researched by the lapping experiment. The research result shows that the cone method is the optimal lapping method with high precision, high efficiency and the very simple machine. Furthermore, the mechanics characteristic of the cone lapping method have been analyzed and summarized, which will provide the basic principle and theoretical basis for the choice of primary geometry and mechanics parameter in the process of ceramic balls lapping.


The internet users are exponentially increasing day by day with a heavy load on spectrum. Li-Fi – a new trending technology opened the doors for communication with high speed. It is a visible light communication to transmit or receive data. The protection of data from unauthorized users is highly needed in this communication in its vicinity. Existing algorithms provides security but it involves lot of processing time which is higher than the communication time. Therefore, light weight algorithms are very much in demand. In this paper, a new light weight security mechanism is presented to avoid the access from others. The proposed mechanism provides better security in Li-Fi communication with high speed for future networks.


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