Dynamic analysis of a multi-span beam subjected to a moving force using the frequency domain spectral element method. (November 2017)

• Record Type: Journal Article
• Authors: Kim, Taehyun; Lee, Usik
• Is Part Of: Computers & structures. Volume 192(2017)
• Page Start: 181
• Page End: 195
• Publication Date: 2017-11
• Subjects: Modified one-element method -- Moving point force -- Multi-span beam -- Spectral element method -- Dynamic responses; Structural engineering -- Data processing -- Periodicals; Electronic data processing -- Structures, Theory of -- Periodicals; 624.171
• DOI: 10.1016/j.compstruc.2017.07.028
• Languages: English
• ISSNs: 0045-7949

Abstract

Highlights: A modified one-element method (MOEM)-based SEM is proposed for multi-span beams under moving point forces. The proposed MOEM provides accurate dynamic responses of a multi-span beam. Accurate MOEM results are obtained by adding correction terms to the results by the one-element method. The effects of the boundary conditions and moving speeds are numerically investigated. Resonance vibrations due to a series of moving point forces are also investigated. Abstract: This study extends a frequency domain modified spectral element method (SEM) from single-span beams to multi-span beams subjected to moving point forces. Each span is represented by the Timoshenko beam model. The time history of the moving point force is transformed to the frequency domain as a series of quasi-static or stationary point forces acting on the beam simultaneously. The dynamic responses are obtained by superposing the individual dynamic responses excited by each quasi-static point force. The SEM based on the original one-element method provides the exact individual dynamic responses of all spans except for the span on which the quasi-static point force is located. Thus, the exact dynamic responses for this span are obtained based on the modified one-element method by adding some correction terms that are given in closed analytical forms. The method is highly accurate and computationally efficient, as verified by comparison with other techniques such as exact theory, modal analysis method, and finite element method.