The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the dam...The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.展开更多
In order to study the dynamic characteristics of a simply supported double-beam system under a moving mass,the system of fourth-order dynamic partial differential equations of a simply supported double-beam system was...In order to study the dynamic characteristics of a simply supported double-beam system under a moving mass,the system of fourth-order dynamic partial differential equations of a simply supported double-beam system was transformed into a system of second-order dynamic ordinary differential equations relative to time coordinates by performing the finite sin-Fourier Transform relative to space coordinates.And the analytical solution of the dynamic response of the simply supported double-beam system under a moving mass was obtained by solving the system of dynamic ordinary differential equations.The analytical method and ANSYS numerical method were used to calculate the dynamic responses of several simply supported double-beam systems under a moving mass at different speeds.The influences of inertial effect,mass movement speed,and Winkler-layer spring stiffness and damping on the dynamic responses of simply supported double-beam systems were analyzed.According to the study results,the analytical calculation results in this paper fit well with the ANSYS finite element numerical calculation results,demonstrating the rationality of the analytical method.The inertial effect has a significant influence on the dynamic response characteristics of the simply supported double-beam system.The simply supported double-beam system underwent several resonant speeds under a moving mass,and the Winkler-layer spring stiffness has a relatively significant effect on the vibration of the first beam.展开更多
With the development of science and technology, the mechanical level is gradually improving, and the types of cranes are also increasing. At present, the electric double-beam bridge crane is most commonly used in our ...With the development of science and technology, the mechanical level is gradually improving, and the types of cranes are also increasing. At present, the electric double-beam bridge crane is most commonly used in our factory, and many safety problems are often encountered in the process of using large machinery like cranes. Under the influence of safety management concept, the use technology of electric double-beam bridge crane needs to be more standardized, and the relevant inspection points need to be sorted out. This paper mainly focuses on the problems in the use of cranes, as well as the troubleshooting measures and maintenance.展开更多
The dynamic characteristics of a beam-cable coupled system are investigated using an improved Chebyshev spectral element method in order to observe the effects of adding cables on the beam. The system is modeled as a ...The dynamic characteristics of a beam-cable coupled system are investigated using an improved Chebyshev spectral element method in order to observe the effects of adding cables on the beam. The system is modeled as a double Timoshenko beam system interconnected by discrete springs. Utilizing Chebyshev series expansion and meshing the system according to the locations of its connections, numerical results of the natural frequencies and mode shapes are obtained using only a few elements, and the results are validated by comparing them with the results of a finite-element method. Then the effects of the cable parameters and layout of connections on the natural frequencies and mode shapes of a fixed-pinned beam are studied. The results show that the modes of a beam-cable coupled system can be classified into two types, beam mode and cable mode, according to the dominant deformation. To avoid undesirable vibrations of the cable, its parameters should be controlled in a reasonable range, or the layout of the connections should be optimized.展开更多
An optimization approach based on Artificial Bee Colony(ABC)algorithm is proposed for structural local damage detection in this study.The objective function for the damage identification problem is established by stru...An optimization approach based on Artificial Bee Colony(ABC)algorithm is proposed for structural local damage detection in this study.The objective function for the damage identification problem is established by structural parameters and modal assurance criteria(MAC).The ABC algorithm is presented to solve the certain objective function.Then the Tournament Selection Strategy and chaotic search mechanism is adopted to enhance global search ability of the certain algorithm.A coupled double-beam system is studied as numerical example to illustrate the correctness and efficiency of the propose method.The simulation results show that the modified ABC algorithm can identify the local damage of the structural system efficiently even under measurement noise,which demonstrates the proposed algorithm has a higher damage diagnosis precision.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 12272323)。
文摘The double-beam system is a crucial foundational structure in industry,with extensive application contexts and significant research value.The double-beam system with damping and gyroscopic effects is termed as the damped gyroscopic double-beam system.In such systems,the orthogonality conditions of the undamped double-beam system are no longer applicable,rendering it impossible to decouple them in modal space using the modal superposition method(MSM) to obtain analytical solutions.Based on the complex modal method and state space method,this paper takes the damped pipe-in-pipe(PIP) system as an example to solve this problem.The concepts of the original system and adjoint system are introduced,and the orthogonality conditions of the damped PIP system are given in the state-space.Based on the derived orthogonality conditions,the transient and steady-state response solutions are obtained.In the numerical discussion section,the convergence and accuracy of the solutions are verified.In addition,the dynamic responses of the system under different excitations and initial conditions are studied,and the forward and reverse synchronous vibrations in the PIP system are discussed.Overall,the method presented in this paper provides a convenient way to analyze the dynamics of the damped gyroscopic double-beam system.
基金The research described in this paper was financially supported by the Fundamental Research Funds for the Central Universities of Central South University(2018zzts189)the National Natural Science Foundations of China(51778630).
文摘In order to study the dynamic characteristics of a simply supported double-beam system under a moving mass,the system of fourth-order dynamic partial differential equations of a simply supported double-beam system was transformed into a system of second-order dynamic ordinary differential equations relative to time coordinates by performing the finite sin-Fourier Transform relative to space coordinates.And the analytical solution of the dynamic response of the simply supported double-beam system under a moving mass was obtained by solving the system of dynamic ordinary differential equations.The analytical method and ANSYS numerical method were used to calculate the dynamic responses of several simply supported double-beam systems under a moving mass at different speeds.The influences of inertial effect,mass movement speed,and Winkler-layer spring stiffness and damping on the dynamic responses of simply supported double-beam systems were analyzed.According to the study results,the analytical calculation results in this paper fit well with the ANSYS finite element numerical calculation results,demonstrating the rationality of the analytical method.The inertial effect has a significant influence on the dynamic response characteristics of the simply supported double-beam system.The simply supported double-beam system underwent several resonant speeds under a moving mass,and the Winkler-layer spring stiffness has a relatively significant effect on the vibration of the first beam.
文摘With the development of science and technology, the mechanical level is gradually improving, and the types of cranes are also increasing. At present, the electric double-beam bridge crane is most commonly used in our factory, and many safety problems are often encountered in the process of using large machinery like cranes. Under the influence of safety management concept, the use technology of electric double-beam bridge crane needs to be more standardized, and the relevant inspection points need to be sorted out. This paper mainly focuses on the problems in the use of cranes, as well as the troubleshooting measures and maintenance.
基金supported by the National Basic Research Program of China (Grant 2013CB733004)
文摘The dynamic characteristics of a beam-cable coupled system are investigated using an improved Chebyshev spectral element method in order to observe the effects of adding cables on the beam. The system is modeled as a double Timoshenko beam system interconnected by discrete springs. Utilizing Chebyshev series expansion and meshing the system according to the locations of its connections, numerical results of the natural frequencies and mode shapes are obtained using only a few elements, and the results are validated by comparing them with the results of a finite-element method. Then the effects of the cable parameters and layout of connections on the natural frequencies and mode shapes of a fixed-pinned beam are studied. The results show that the modes of a beam-cable coupled system can be classified into two types, beam mode and cable mode, according to the dominant deformation. To avoid undesirable vibrations of the cable, its parameters should be controlled in a reasonable range, or the layout of the connections should be optimized.
基金the National Natural Science Foundation of China(11172333,11272361)the Fundamental Research Funds for the Central Universities(13lgzd06)+1 种基金Doctoral Program Foundation of Ministry of Education of China(20130171110039)the Guangdong Province Science and Technology Program(2012A030200011)。
文摘An optimization approach based on Artificial Bee Colony(ABC)algorithm is proposed for structural local damage detection in this study.The objective function for the damage identification problem is established by structural parameters and modal assurance criteria(MAC).The ABC algorithm is presented to solve the certain objective function.Then the Tournament Selection Strategy and chaotic search mechanism is adopted to enhance global search ability of the certain algorithm.A coupled double-beam system is studied as numerical example to illustrate the correctness and efficiency of the propose method.The simulation results show that the modified ABC algorithm can identify the local damage of the structural system efficiently even under measurement noise,which demonstrates the proposed algorithm has a higher damage diagnosis precision.
