SENSITIVITY STUDY OF THE STEEL FOOTBRIDGE RESPONSE TO THE DAMPER PARAMETERS

conference paper

English

The paper presents an optimization study of a Tuned Mass Damper (TMD) located on the structure of a steel footbridge. Lightweight bridge structures are prone to dynamic responses caused by human induced vibrations. In some cases, an TMD may be used to limit this response. The TMD is tuned to only one dominant natural frequency. In static response or when oscillating with another frequency, it only acts as an additional load. Therefore, it is necessary to find a suitable ratio of efficiency and weight of the damper. The effective modal weight of a structure is the weight of the part of the structure that oscillates in a given direction at a certain natural frequency of the structure. If we want to obtain the optimal course of the amplitude-frequency dependence, it must be tuned using the stiffness and damping parameters. The stiffness of the vibration damper is affected by the difference between the maxima of the two amplitudes. The damping of TMD affects the shape of the amplitude-frequency response so that with a small damping there is a larger drop between the peaks of the amplitudes and in the case of a damping of the structure, the two maxima merge into one larger one. In the first phase, the damper weight is calculated on the basis of a formula based on a 5% proportion of the oscillating modal mass thus determined. Stiffness and damping are also determined in this way. Subsequently, an optimization calculation of the response of the structure with variable values of vibration damper parameters was performed using the ANSYS and OptiSlang software systems. We are looking for values of vibration damper parameters for which the response value will be the smallest when the structure is loaded. The response is monitored in the form of the amplitude of the deflection of the structure in the middle of the span. For random studies the two degree of freedom model was used. The result of the study is the dependence of this value on the variability of individual input parameters with robust interval defined.

Sensitivity, damper parameters, footbridge

KALA, J.; KALA, Z.; JINDRA, D.

27. 9. 2023

AIP Publishing

9780735446632

World Multidisciplinary Civil Engineering-Architecture-Urban Planning Symposium - WMCAUS 2022

0094-243X

AIP conference proceedings

2928

1

United States of America

150039-1

150039-6

6

https://pubs.aip.org/aip/acp/article/2928/1/150039/2913340/Sensitivity-study-of-the-steel-footbridge-response?searchresult=1