scholarly journals Vibration characteristic analysis of single-cylinder two-stroke engine and mounting system optimization design

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042093063
Author(s):  
Jinhui Liang ◽  
Dongdong Zhang ◽  
Shuwen Wang

Compared with four-stroke engines, single-cylinder two-stroke engines have the characteristics of small inertia, high rotational speed, and wide excitation frequency range. However, the structural vibration and noise generated by the two-stroke engine are very violent. Hence, it is necessary to reduce the vibration and noise of the single-cylinder two-stroke engine. Based on the design theory of the engine mounting system, the excitation frequency, direction, and magnitude of a single-cylinder two-stroke engine are analyzed. The rubber isolator is selected as the new mount element, and the dynamic model of the engine powertrain mounting system is established based on ADAMS software. Based on the sensitivity analysis of the design variables of the mounting system, the natural frequency of the mounting system is used as an objective, and the three-directional stiffness of the mounting system is taken as design variables for the optimization problem. The optimization model is solved by the sequential quadratic programming method. The results show that the maximum frequency of the mounting system after optimization is less than 1/[Formula: see text] of the excitation frequency, and the isolation effect is achieved. The dynamic model and the optimization method presented in this article would provide a useful tool for the design and optimization of mounting system for the single-cylinder two-stroke engine to reduce vibration from the engine to the engine support.

2010 ◽  
Vol 431-432 ◽  
pp. 425-428
Author(s):  
Kan Zheng ◽  
Wen He Liao ◽  
Xiang Zhang

According to the structural layout and mechanics characteristic of microsatellite, the FEM was established reasonably. Base on the FEM analysis and its characteristics, the structure of microsatellite was optimization designed. In the optimization process, the optimization model was established with the design variables of aluminum panel thickness, core plate thickness and skeleton thickness, and subjected to stiffness, strength, displacement and size constraints. Then, used the sequential quadratic programming method for optimization analysis. The results of the optimization demonstrates that the weight of structure loss significantly, and the whole structure weight of the microsatellite loss 11%.Meanwhile, the iterative times of the optimization process is few, so it is very Meaningful and useful for actual project application.


2013 ◽  
Vol 859 ◽  
pp. 270-273 ◽  
Author(s):  
Xiao Xiong Zha ◽  
Yang Zuo ◽  
Shi Yun Chen

Container, as a light steel structure, being increasingly used in building construction, containers used in construction has many advantages and applications. However, the current study mostly from the view of the architecture, as for the mechanical properties of the container building has not mentioned, that brings obstacles of the application and development of the container building. Based on the software package of HyperWorks and optimization design theory, the cross-sectional size of container building is taken as design variables, and then selected objective function and constraint functions. Finally, calculated by software, get the optimal cross-sectional dimension.


2010 ◽  
Vol 44-47 ◽  
pp. 1505-1508
Author(s):  
Xiang Yang Chen ◽  
Heng Zhen Yan

Aiming at the phenomenon of the more conservative design of deep cement stirring pile currently, used optimization design theory such as genetic algorithm and particle swarm optimization, taken the cement consumption as the object function, taken replacement rate, water-cement ratio, pile diameter and pile length as the design variables, composite foundation bearing capacity and settlement as restrictive conditions, the optimal design models are established respectively based on genetic algorithm and particle swarm optimization. Case studies have shown that these two established models are effective. By comparison, the particle swarm optimization model is the more effective one.


2012 ◽  
Vol 229-231 ◽  
pp. 613-616
Author(s):  
Yan Jue Gong ◽  
Yuan Yuan Zhang ◽  
Fu Zhao ◽  
Hui Yu Xiang ◽  
Chun Ling Meng ◽  
...  

As an important part of the vertical axis wind turbine, the support structure should have high strength and stiffness. This article adopts finite element method to model a kind of tower structure of the vertical axis wind turbine and carry out static and modal analysis. The static and dynamic characteristic results of tower in this paper provide reference for optimization design the support structure of wind turbine further.


Author(s):  
Mustafa Babagiray ◽  
Hamit Solmaz ◽  
Duygu İpci ◽  
Fatih Aksoy

In this study, a dynamic model of a single-cylinder four-stroke diesel engine has been created, and the crankshaft speed fluctuations have been simulated and validated. The dynamic model of the engine consists of the motion equations of the piston, conrod, and crankshaft. Conrod motion was modeled by two translational and one angular motion equations, by considering the kinetic energy resulted from the mass moment of inertia and conrod mass. Motion equations involve in-cylinder gas pressure forces, hydrodynamic and dry friction, mass inertia moments of moving parts, starter moment, and external load moment. The In-cylinder pressure profile used in the model was obtained experimentally to increase the accuracy of the model. Pressure profiles were expressed mathematically using the Fourier series. The motion equations were solved by using the Taylor series method. The solution of the mathematical model was performed by coding in the MATLAB interface. Cyclic speed fluctuations obtained from the model were compared with experimental results and found compitable. A validated model was used to analyze the effects of in-cylinder pressure, mass moment of inertia of crankshaft and connecting rod, friction, and piston mass. In experiments for 1500, 1800, 2400, and 2700 rpm engine speeds, crankshaft speed fluctuations were observed as 12.84%, 8.04%, 5.02%, and 4.44%, respectively. In simulations performed for the same speeds, crankshaft speed fluctuations were calculated as 10.45%, 7.56%, 4.49%, and 3.65%. Besides, it was observed that the speed fluctuations decreased as the average crankshaft speed value increased. In the simulation for 157.07, 188.49, 219.91, 251.32, and 282.74 rad/s crankshaft speeds, crankshaft speed fluctuations occurred at rates of 10.45%, 7.56%, 5.84%, 4.49%, and 3.65%, respectively. The effective engine power was achieved as 5.25 kW at an average crankshaft angular speed of 219.91 rad/s. The power of friction loss in the engine was determined as 0.68 kW.


2009 ◽  
Vol 626-627 ◽  
pp. 693-698
Author(s):  
Yong Yong Zhu ◽  
S.Y. Gao

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.


2016 ◽  
Vol 693 ◽  
pp. 243-250
Author(s):  
Zhi Zhong Guo ◽  
Yun Shun Zhang ◽  
Shi Hao Liu

It is discovered that the vibration resistance of spindle systems needs to be improved based on the statics analysis, modal analysis and heating-force coupling analysis of spindle systems of CNC gantry machine tools. The design variables of optimization are set according to sensitivity analysis, multi-objective and dynamic optimization design is realized and its designing scheme is gained for spindle structure. The research results show that vibration resistance can be improved without change of the quality and static property of spindle systems of CNC gantry machine tools.


2012 ◽  
Vol 430-432 ◽  
pp. 828-833
Author(s):  
Qiu Sheng Ma ◽  
Yi Cai ◽  
Dong Xing Tian

In this paper, based on ANSYS the topology optimization design for high pressure storage tank was studied by the means of the finite element structural analysis and optimization. the finite element model for optimization design was established. The design variables influence factors and rules on the optimization results are summarized. according to the calculation results the optimal design result for tank is determined considering the manufacturing and processing. The calculation results show that the method is effective in optimization design and provide the basis to further design high pressure tank.


2015 ◽  
Vol 07 (06) ◽  
pp. 1550085 ◽  
Author(s):  
Z. C. He ◽  
G. Y. Zhang ◽  
L. Deng ◽  
Eric Li ◽  
G. R. Liu

The node-based smoothed finite element method (NS-FEM) proposed recently has shown very good properties in solid mechanics, such as providing much better gradient solutions. In this paper, the topology optimization design of the continuum structures under static load is formulated on the basis of NS-FEM. As the node-based smoothing domain is the sub-unit of assembling stiffness matrix in the NS-FEM, the relative density of node-based smoothing domains serves as design variables. In this formulation, the compliance minimization is considered as an objective function, and the topology optimization model is developed using the solid isotropic material with penalization (SIMP) interpolation scheme. The topology optimization problem is then solved by the optimality criteria (OC) method. Finally, the feasibility and efficiency of the proposed method are illustrated with both 2D and 3D examples that are widely used in the topology optimization design.


2014 ◽  
Vol 548-549 ◽  
pp. 383-388
Author(s):  
Zhi Wei Chen ◽  
Zhe Cui ◽  
Yi Jin Fu ◽  
Wen Ping Cui ◽  
Li Juan Dong ◽  
...  

Parametric finite element model for a commonly used telescopic boom structure of a certain type of truck-mounted crane has been established. Static analysis of the conventional design configuration was performed first. And then an optimization process has been carried out to minimize the total weight of the telescopic structures. The design variables include the geometric shape parameters of the cross-sections and the integrated structural parameters of the telescopic boom. The constraints include the maximum allowable equivalent stresses and the flexure displacements at the tip of the assembled boom structure in both the vertical direction and the circumferential direction of the rotating plane. Compared with the conventional design, the optimization design has achieved a significant weight reduction of up to 24.3%.


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