Reinforcement of slopes using soil nailing can effectively improve slope stability, and it has been widely used in upgrading cut slopes. Based on the assumptions of stresses on the slip surface, a new method for analy...Reinforcement of slopes using soil nailing can effectively improve slope stability, and it has been widely used in upgrading cut slopes. Based on the assumptions of stresses on the slip surface, a new method for analyzing the stability of a slope reinforced with soil nails was established in the limit equilibrium theory framework, by considering that slope sliding occurs owing to shear failure of the slip surface, which subjects to Mohr–Coulomb(M–C) strength criterion. Meanwhile, in order to easily analyze the stability of a soil nailed slope in actual engineering and facilitate optimum design of parameters for soil nailing, factor of safety(FOS) contour curve charts were drawn on the basis of the established linear proportional relationship between the spacing of soil nails and slope height, and the length of soil nails and slope height. Then, by analyzing and verifying the results obtained from classic examples, some conclusions can be got as follows: 1) The results obtained from the current method are close to those obtained from the traditional limit equilibrium methods, and the current method can provide a strict solution for the slope FOS as it satisfies all the static equilibrium conditions of a sliding body, thus confirming the feasibility of the current method; 2) The slope FOS contour curve charts can be used not only to reliably analyze the stability of a soil nailed slope, but also to design optimally the parameters of soil nailing for the slope with a certain safety requirement.展开更多
Due to a viscoelastic damping middle layer,sandwich structures have the capacity of energy consumption.In this paper,we describe the frequency-dependent property of viscoelastic materials using complex modulus model,a...Due to a viscoelastic damping middle layer,sandwich structures have the capacity of energy consumption.In this paper,we describe the frequency-dependent property of viscoelastic materials using complex modulus model,and iterative modal strain energy method and iterative complex eigenvalue method are presented to obtain frequency and loss factor of sandwich structures.The two methods are effective and exact for the large-scale complex composite sandwich structures.Then an optimum analysis method is suggested to apply to sandwich structures.Finally,as an example,an optimum analysis of a clamped-clamped sandwich beams is conducted,theoretical closed-form solution and numerical predictions are studied comparatively,and the results agree well.展开更多
在传统感应耦合电能传输(inductively coupled power transfer,ICPT)系统拓扑中,系统谐振频率漂移会引起传输效率下降。针对该问题,提出一种新型的基于LCL谐振型ICPT系统拓扑。采用基波分析法对其等效电路模型进行分析,得出不同品质因数...在传统感应耦合电能传输(inductively coupled power transfer,ICPT)系统拓扑中,系统谐振频率漂移会引起传输效率下降。针对该问题,提出一种新型的基于LCL谐振型ICPT系统拓扑。采用基波分析法对其等效电路模型进行分析,得出不同品质因数下,系统的电压、电流增益与开关频率的特性曲线,并分析得出该拓扑具有较高的功率因数。为实现了ICPT系统软开关,提出了谐振元件参数优化设计的方法。基于所优化的参数结果,分析了品质因数和耦合系数的选择对谐振元件电压电流应力的影响。最后,设计了一台基于LCL谐振型ICPT系统样机,实验结果证明了所提方法的可行性。展开更多
基金Project(2015M580702)supported by the Postdoctoral Science Foundation of ChinaProject(51608541)supported by the National Natural Science Foundation of ChinaProject(2014122066)supported by the Guizhou Provincial Department of Transportation Foundation,China
文摘Reinforcement of slopes using soil nailing can effectively improve slope stability, and it has been widely used in upgrading cut slopes. Based on the assumptions of stresses on the slip surface, a new method for analyzing the stability of a slope reinforced with soil nails was established in the limit equilibrium theory framework, by considering that slope sliding occurs owing to shear failure of the slip surface, which subjects to Mohr–Coulomb(M–C) strength criterion. Meanwhile, in order to easily analyze the stability of a soil nailed slope in actual engineering and facilitate optimum design of parameters for soil nailing, factor of safety(FOS) contour curve charts were drawn on the basis of the established linear proportional relationship between the spacing of soil nails and slope height, and the length of soil nails and slope height. Then, by analyzing and verifying the results obtained from classic examples, some conclusions can be got as follows: 1) The results obtained from the current method are close to those obtained from the traditional limit equilibrium methods, and the current method can provide a strict solution for the slope FOS as it satisfies all the static equilibrium conditions of a sliding body, thus confirming the feasibility of the current method; 2) The slope FOS contour curve charts can be used not only to reliably analyze the stability of a soil nailed slope, but also to design optimally the parameters of soil nailing for the slope with a certain safety requirement.
文摘Due to a viscoelastic damping middle layer,sandwich structures have the capacity of energy consumption.In this paper,we describe the frequency-dependent property of viscoelastic materials using complex modulus model,and iterative modal strain energy method and iterative complex eigenvalue method are presented to obtain frequency and loss factor of sandwich structures.The two methods are effective and exact for the large-scale complex composite sandwich structures.Then an optimum analysis method is suggested to apply to sandwich structures.Finally,as an example,an optimum analysis of a clamped-clamped sandwich beams is conducted,theoretical closed-form solution and numerical predictions are studied comparatively,and the results agree well.
文摘在传统感应耦合电能传输(inductively coupled power transfer,ICPT)系统拓扑中,系统谐振频率漂移会引起传输效率下降。针对该问题,提出一种新型的基于LCL谐振型ICPT系统拓扑。采用基波分析法对其等效电路模型进行分析,得出不同品质因数下,系统的电压、电流增益与开关频率的特性曲线,并分析得出该拓扑具有较高的功率因数。为实现了ICPT系统软开关,提出了谐振元件参数优化设计的方法。基于所优化的参数结果,分析了品质因数和耦合系数的选择对谐振元件电压电流应力的影响。最后,设计了一台基于LCL谐振型ICPT系统样机,实验结果证明了所提方法的可行性。
