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Yusuf Yesilce - One of the best experts on this subject based on the ideXlab platform.
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crack identification in multi Span Beams on elastic foundation by using transfer matrix method
Proceedings of the 13th International Conference on Damage Assessment of Structures, 2020Co-Authors: Baran Bozyigit, Yusuf Yesilce, Irem Bozyigit, Abdel M WahabAbstract:In this study, an analytical based approach is proposed for detection of cracks in multi-Span Euler-Bernoulli Beams on Winkler foundation. Transfer matrix method (TMM) is used for both forward and inverse problems. The crack is modeled by means of a linear rotational spring. For the forward problem, natural frequencies of intact and cracked multi-Span Beam models are calculated via TMM for two different support arrangements and the results are compared with those obtained using finite element method (FEM). In the inverse problem, the crack location and crack length are calculated based on the natural frequencies obtained from FEM simulations using plots of rotational spring flexibilities versus crack location. The predicted crack properties are tabulated with actual data. It is seen that considering elastic foundation slightly decreases the accuracy of crack depth prediction for multi-Span Beams. However, the accuracy of localization of crack is not affected by Winkler foundation.
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effect of axial force on the free vibration of reddy bickford multi Span Beam carrying multiple spring mass systems
Journal of Vibration and Control, 2010Co-Authors: Yusuf YesilceAbstract:Structural elements supporting motors or engines are frequently seen in technological applications. The operation of a machine may introduce additional dynamic stresses on the Beam. It is important to know the natural frequencies of the coupled Beam—mass system for a proper design of the structural elements. There is plenty of literature regarding the free vibration analysis of Bernoulli—Euler single-Span Beams carrying a number of spring—mass system and Bernoulli—Euler multi-Span Beams carrying multiple spring—mass systems, but less is available regarding Reddy—Bickford multi-Span Beam carrying multiple spring—mass systems with/without axial force effect. This paper aims at determining the exact solutions for the first five natural frequencies and mode shapes of Reddy—Bickford Beams. The model allows the influence of the shear effect and spring—mass systems on the dynamic behavior of the Beams to be analyzed by using Reddy—Bickford Beam theory. The effects of the attached spring—mass systems on the free ...
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Effect of axial force on free vibration of Timoshenko multi-Span Beam carrying multiple spring-mass systems
International Journal of Mechanical Sciences, 2008Co-Authors: Yusuf Yesilce, Oktay DemirdagAbstract:Abstract The situation of structural elements supporting motors or engines attached to them is usual in technological applications. The operation of machine may introduce severe dynamic stresses on the Beam. It is important, then, to know the natural frequencies of the coupled Beam-mass system, in order to obtain a proper design of the structural elements. The literature regarding the free vibration analysis of Bernoulli–Euler single-Span Beams carrying a number of spring-mass system and Bernoulli–Euler multi-Span Beams carrying multiple spring-mass systems are plenty, but that of Timoshenko multi-Span Beams carrying multiple spring-mass systems with axial force effect is fewer. This paper aims at determining the exact solutions for the first five natural frequencies and mode shapes of a Timoshenko multi-Span Beam subjected to the axial force. The model allows analyzing the influence of the shear and axial force effects and spring-mass systems on the dynamic behavior of the Beams by using Timoshenko Beam Theory (TBT). The effects of attached spring-mass systems on the free vibration characteristics of the 1–4 Span Beams are studied. The calculated natural frequencies of Timoshenko multi-Span Beam by using secant method for non-trivial solution for the different values of axial force are given in tables. The mode shapes are presented in graphs.
Oktay Demirdag - One of the best experts on this subject based on the ideXlab platform.
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Effect of axial force on free vibration of Timoshenko multi-Span Beam carrying multiple spring-mass systems
International Journal of Mechanical Sciences, 2008Co-Authors: Yusuf Yesilce, Oktay DemirdagAbstract:Abstract The situation of structural elements supporting motors or engines attached to them is usual in technological applications. The operation of machine may introduce severe dynamic stresses on the Beam. It is important, then, to know the natural frequencies of the coupled Beam-mass system, in order to obtain a proper design of the structural elements. The literature regarding the free vibration analysis of Bernoulli–Euler single-Span Beams carrying a number of spring-mass system and Bernoulli–Euler multi-Span Beams carrying multiple spring-mass systems are plenty, but that of Timoshenko multi-Span Beams carrying multiple spring-mass systems with axial force effect is fewer. This paper aims at determining the exact solutions for the first five natural frequencies and mode shapes of a Timoshenko multi-Span Beam subjected to the axial force. The model allows analyzing the influence of the shear and axial force effects and spring-mass systems on the dynamic behavior of the Beams by using Timoshenko Beam Theory (TBT). The effects of attached spring-mass systems on the free vibration characteristics of the 1–4 Span Beams are studied. The calculated natural frequencies of Timoshenko multi-Span Beam by using secant method for non-trivial solution for the different values of axial force are given in tables. The mode shapes are presented in graphs.
Jordi Madrenas - One of the best experts on this subject based on the ideXlab platform.
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closed form equation for natural frequencies of Beams under full range of axial loads modeled with a spring mass system
International Journal of Mechanical Sciences, 2019Co-Authors: Juan Valle, Daniel Fernandez, Jordi MadrenasAbstract:Abstract A new simple closed-form equation that accurately predicts the effect of an arbitrarily large constant axial load, residual stress or temperature shift on the natural frequencies of an uniform single-Span Beam, with various end conditions, is presented. Its accuracy and applicability range are studied by comparing its predictions with numerical simulations and with the approximate Galef’s and Bokaian’s formulas. The new equation may be understood as a refinement or extension of these two approximate formulas. Significant accuracy and applicability range improvements are achieved, especially near the buckling point and for large and moderate axial load. The new closed-form equation is applicable in the full range of axial load, i.e., from the buckling load to the tensioned-string limit. It also models well the Beam-to-string transition region for the eight boundary conditions studied. It works remarkably well in the free-free and sliding-free cases, where it is a near-exact solution. In addition, it yields the natural frequencies of a 1-D spring-mass system that may be used to model tensioned Beams, and potentially, more complex systems.
Juan Valle - One of the best experts on this subject based on the ideXlab platform.
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closed form equation for natural frequencies of Beams under full range of axial loads modeled with a spring mass system
International Journal of Mechanical Sciences, 2019Co-Authors: Juan Valle, Daniel Fernandez, Jordi MadrenasAbstract:Abstract A new simple closed-form equation that accurately predicts the effect of an arbitrarily large constant axial load, residual stress or temperature shift on the natural frequencies of an uniform single-Span Beam, with various end conditions, is presented. Its accuracy and applicability range are studied by comparing its predictions with numerical simulations and with the approximate Galef’s and Bokaian’s formulas. The new equation may be understood as a refinement or extension of these two approximate formulas. Significant accuracy and applicability range improvements are achieved, especially near the buckling point and for large and moderate axial load. The new closed-form equation is applicable in the full range of axial load, i.e., from the buckling load to the tensioned-string limit. It also models well the Beam-to-string transition region for the eight boundary conditions studied. It works remarkably well in the free-free and sliding-free cases, where it is a near-exact solution. In addition, it yields the natural frequencies of a 1-D spring-mass system that may be used to model tensioned Beams, and potentially, more complex systems.
Raid Karoumi - One of the best experts on this subject based on the ideXlab platform.
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closed form solution for the mode superposition analysis of the vibration in multi Span Beam bridges caused by concentrated moving loads
Computers & Structures, 2013Co-Authors: Christoffer Johansson, Costin Pacoste, Raid KaroumiAbstract:In this paper, a closed-form solution for evaluating the dynamical behavior of a general multi-Span Bernoulli-Euler Beam is derived. The natural frequencies of vibration and corresponding mode shapes are obtained by applying the boundary conditions to the characteristic function of a Beam. A Laplace transformation is applied to the governing differential equation which is then solved for each normal mode in the frequency domain. The main contribution of this paper is to provide a closed-form solution for the vibration of continuous stepped Beams under constant moving loads. Several numerical examples are included.