• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.3
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• pp.751-756
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• 1991

본 연구에서는 Ashwell이 제시한 변형률요소를 전단효과를 고려한 두꺼운 곡 선보 요소에 적용 하였다. 막 변형률, 곡률, 전단변형률 각각에 독립된 변형률 함수 를 가정하여 미분 방정식의 일반해를 구하면 정확한 강체변위의 표현은 물론, 강성과 잉현상을 피할 수 있고 얇은 곡선보에서 두꺼운 곡선보에 이르기까지 보의 해석에 있 어서, 2절점으로 구성되는 적은 자유도수에서 높은 정확도를 보여주는 간편하고도 효 율적인 요소를 개발하고자 하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.623-628
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• 2004

In this study, the assumed-mode method using characteristic polynomials of Timoshenko beam is applied for the free vibration analysis of rectangular stiffened plates. The polynomial is derived considering the rotational constraint along the boundary edges of plate and the orthogonal relation of Timoshenko beam functions, which enables to simplify the free vibration analysis of plate structure having various boundary conditions. To verify the validity and effectiveness of the adopted method, numerical analysis for cross-stiffened plates were carried out and its results were compared with those obtained by the general purpose FEA software.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.202-211
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• 1998

The present paper proposes a modal analysis procedure to obtain exact modal parameters (natural frequencies, damping ratios, eigenvectors) for general, non-uniform beam-like structures. The proposed method includes a derivation of the system dynamic matrix for a Timoshenko beam element. The proposed method provides not only exact modal parameters but also exact frequency response functions (FRFs) for general beam structures. A time domain analysis method is also proposed. Two examples are provided for validating and illustrating the proposed method. The first numerical example compares the proposed method with FEM. The second example deals with a non-uniform beam structure supported in joints with damping property. The numerical study proves that the proposed method is useful for the dynamic analysis of continuous systems consisting of beam-like structures.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.42-49
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• 2012

A numerical method is presented for an out-of-plane structural intensity analysis of rectangular thick plates with arbitrary elastic edge constraints. The method adapts an assumed mode method based on Timoshenko beam functions to obtain the velocities and internal forces needed for a structural intensity analysis. To verify the presented method, the structural intensity of a square thick plate under harmonic force excitation, for which four edges are simply supported, is analyzed, and the result is compared with existing solutions using the assumed mode method based on trigonometric functions. In addition, numerical analyses are carried out for a rectangular-shaped thick plate under harmonic force excitations, of which three edges are simply supported and one edge utilizes an arbitrary elastic edge constraint. These numerical examples show the good accuracy and applicability of the presented method for rectangular thick plates with arbitrary edge constraints.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1125-1131
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• 2014

This work presents a vulnerability assessment procedure for a complex structure using vibration characteristics. The structural behavior of a three-dimensional framed structure subjected to impact forces was predicted using the spectral element method. The Timoshenko beam function was applied to simulate the impact wave propagations induced by a high-velocity projectile at relatively high frequencies. The interactions at the joints were analyzed for both flexural and longitudinal wave propagations. Simulations of the impact energy transfer through the entire structure were performed using the transient displacement and acceleration responses obtained from the frequency analysis. The kill probabilities of the crucial components for an operating system were calculated as a function of the predicted acceleration amplitudes according to the acceptable vibration levels. Following the proposed vulnerability assessment procedure, the vulnerable positions of a three-dimensional combat vehicle with high possibilities of damage generation of components by impact loading were identified from the estimated vibration responses.