Based on ANSYS software, a finite element model is built for the fatigue break of a vibration feeder influenced by an exciting force alternate load. We first study the harmonic response of the feeder and discovers the...Based on ANSYS software, a finite element model is built for the fatigue break of a vibration feeder influenced by an exciting force alternate load. We first study the harmonic response of the feeder and discovers the weak links which is an angle steel junction of side plate, feed inlet and the junction panel between the no-feed side plate and the bottom plate. Then, we carry out structural optimization. A streamlined method for optimum design of a vibration feeder is presented.展开更多
In this paper, using the theory of stochastic analysis of the response to earthquake load, a stochastic analysis method of the response of piled platforms to earthquake load has been established. In the method, the st...In this paper, using the theory of stochastic analysis of the response to earthquake load, a stochastic analysis method of the response of piled platforms to earthquake load has been established. In the method, the strong ground motion is considered as three dimensional stationary white noise process and the pile-soil interaction and water-structure interaction are considered. The stochastic response of a typical platform to earthquake load has been computed with this method and the results compared with those obtained with the response spectrum analysis method. The comparison shows that the stochastic analysis method of the response of piled platforms to earthquake load is suitable for this kind of analysis.展开更多
In order to reduce casualties and property losses in a collision accident, thin-walled structure has been extensively used as energy absorber in crashworthiness design of train. With the help of energy absorber, colli...In order to reduce casualties and property losses in a collision accident, thin-walled structure has been extensively used as energy absorber in crashworthiness design of train. With the help of energy absorber, collision kinetic energy can be controllably dissipated by the plastic deformation of structures. A new kind of multi-cell thin-walled structure called as bitubular polygonal tubes with internal walls(BPTIW) was constructed. The crashworthiness characteristics of BPTIWs were investigated by LS-DYNA. It can be found that the BPTIW with 12 sides has the most excellent crashworthiness characteristics. Therefore, based on response surface method(RSM) and multiobjective particle optimization(MOPSO) algorithm, the BPTIW with 12 sides was selected to optimize the dimensions of cross-sectional configuration under different constraints of energy absorption(EA) and crushing peak force(CPF). The results show that the optimal designs of BPTIW12 under different constraints present excellent crashworthiness characteristics and can be used in the practical engineering.展开更多
Vibrational characteristics in small horizontal axis wind turbine system are presented in this study with a system concept called tactile response and substructuring.The main focus is on managing the dynamic propertie...Vibrational characteristics in small horizontal axis wind turbine system are presented in this study with a system concept called tactile response and substructuring.The main focus is on managing the dynamic properties like vibration,noise,and harshness that occur during the operational mode.Tactile response is defined as the response of subsystem which is induced when a human body touches a vibrating system.Sub structuring is a computational method used to reduce the dynamic behavior of a large complex system with a smaller number of degrees of freedom without disturbing the mesh size of the model.Sub structuring has the ability to combine numerical results along with the experimental results.Combination of substructuring and tactile response is applied in this study.Mode shapes of the system are analyzed and results obtained are correlated within this study to provide better optimization of the results.Wind turbine excited with wind energy depends on wind speed.Torsional vibration has a significant role in determining dynamic properties.Torsional vibration is caused as a result of the rotation of the turbine blade and depends on wind speed.The study gives importance to investigating the ability to simulate the numerical method and tactile response to predict and improve dynamic properties.展开更多
拓扑优化设计是结构设计中降低成本和实现轻量化的关键环节。能量有限元法(energy finite element analysis,EFEA)是高频动响应分析的有力工具。在高频动力学拓扑优化中,用能量有限元法代替有限元法(finite element analysis,FEA)进行...拓扑优化设计是结构设计中降低成本和实现轻量化的关键环节。能量有限元法(energy finite element analysis,EFEA)是高频动响应分析的有力工具。在高频动力学拓扑优化中,用能量有限元法代替有限元法(finite element analysis,FEA)进行动响应计算可以获得较高的计算效率和计算精度。为了使能量有限元求解和拓扑优化过程能够有效衔接,促进基于能量有限元法的高频动力学拓扑优化的工程应用,建立了基于能量有限元法的多目标拓扑优化模型。基于能量有限元法,以最小能量柔度和感兴趣单元最小能量密度作为高频动力学拓扑优化的目标函数,采用“线性加权法”,建立多目标情况下的拓扑数学模型;再对模型进行离散化,进而对其进行灵敏度计算,通过灵敏度过滤和最优化准则得到多目标拓扑优化构型。最后通过算例,分析不同激励频率对拓扑构型的影响,揭示不同目标权重系数对拓扑构型的交叉影响规律。结果表明,当权重系数相同,激励频率不同时,中高频的减重百分比较低频大;当频率相同,权重系数比为1∶1时,减重百分比最大。基于能量有限元的高频动力学拓扑优化模型有利于发展飞行器等易诱发高频振动的结构的优化设计理论,优化设计结果对实际的结构设计具有一定的参考价值。展开更多
文摘Based on ANSYS software, a finite element model is built for the fatigue break of a vibration feeder influenced by an exciting force alternate load. We first study the harmonic response of the feeder and discovers the weak links which is an angle steel junction of side plate, feed inlet and the junction panel between the no-feed side plate and the bottom plate. Then, we carry out structural optimization. A streamlined method for optimum design of a vibration feeder is presented.
文摘In this paper, using the theory of stochastic analysis of the response to earthquake load, a stochastic analysis method of the response of piled platforms to earthquake load has been established. In the method, the strong ground motion is considered as three dimensional stationary white noise process and the pile-soil interaction and water-structure interaction are considered. The stochastic response of a typical platform to earthquake load has been computed with this method and the results compared with those obtained with the response spectrum analysis method. The comparison shows that the stochastic analysis method of the response of piled platforms to earthquake load is suitable for this kind of analysis.
基金Project(CX2016B047)supported by Hunan Provincial Innovation Foundation For Postgraduate,ChinaProjects(U1334208,51405516,51275532)supported by the National Natural Science Foundation of ChinaProject(2016YFB1200403)supported by the National Key Research and Development Proguam of China
文摘In order to reduce casualties and property losses in a collision accident, thin-walled structure has been extensively used as energy absorber in crashworthiness design of train. With the help of energy absorber, collision kinetic energy can be controllably dissipated by the plastic deformation of structures. A new kind of multi-cell thin-walled structure called as bitubular polygonal tubes with internal walls(BPTIW) was constructed. The crashworthiness characteristics of BPTIWs were investigated by LS-DYNA. It can be found that the BPTIW with 12 sides has the most excellent crashworthiness characteristics. Therefore, based on response surface method(RSM) and multiobjective particle optimization(MOPSO) algorithm, the BPTIW with 12 sides was selected to optimize the dimensions of cross-sectional configuration under different constraints of energy absorption(EA) and crushing peak force(CPF). The results show that the optimal designs of BPTIW12 under different constraints present excellent crashworthiness characteristics and can be used in the practical engineering.
文摘Vibrational characteristics in small horizontal axis wind turbine system are presented in this study with a system concept called tactile response and substructuring.The main focus is on managing the dynamic properties like vibration,noise,and harshness that occur during the operational mode.Tactile response is defined as the response of subsystem which is induced when a human body touches a vibrating system.Sub structuring is a computational method used to reduce the dynamic behavior of a large complex system with a smaller number of degrees of freedom without disturbing the mesh size of the model.Sub structuring has the ability to combine numerical results along with the experimental results.Combination of substructuring and tactile response is applied in this study.Mode shapes of the system are analyzed and results obtained are correlated within this study to provide better optimization of the results.Wind turbine excited with wind energy depends on wind speed.Torsional vibration has a significant role in determining dynamic properties.Torsional vibration is caused as a result of the rotation of the turbine blade and depends on wind speed.The study gives importance to investigating the ability to simulate the numerical method and tactile response to predict and improve dynamic properties.
文摘拓扑优化设计是结构设计中降低成本和实现轻量化的关键环节。能量有限元法(energy finite element analysis,EFEA)是高频动响应分析的有力工具。在高频动力学拓扑优化中,用能量有限元法代替有限元法(finite element analysis,FEA)进行动响应计算可以获得较高的计算效率和计算精度。为了使能量有限元求解和拓扑优化过程能够有效衔接,促进基于能量有限元法的高频动力学拓扑优化的工程应用,建立了基于能量有限元法的多目标拓扑优化模型。基于能量有限元法,以最小能量柔度和感兴趣单元最小能量密度作为高频动力学拓扑优化的目标函数,采用“线性加权法”,建立多目标情况下的拓扑数学模型;再对模型进行离散化,进而对其进行灵敏度计算,通过灵敏度过滤和最优化准则得到多目标拓扑优化构型。最后通过算例,分析不同激励频率对拓扑构型的影响,揭示不同目标权重系数对拓扑构型的交叉影响规律。结果表明,当权重系数相同,激励频率不同时,中高频的减重百分比较低频大;当频率相同,权重系数比为1∶1时,减重百分比最大。基于能量有限元的高频动力学拓扑优化模型有利于发展飞行器等易诱发高频振动的结构的优化设计理论,优化设计结果对实际的结构设计具有一定的参考价值。
