Dynamic Response of a Flexible Structure with Internal Actuating System to Enhance Performance

Hailstone-induced dynamic responses of pretensioned umbrella membrane structure

Advances in Structural Engineering ◽

10.1177/1369433220940149 ◽

2020 ◽

Vol 24 (1) ◽

pp. 3-16 ◽

Cited By ~ 5

Author(s):

Changjiang Liu ◽

Fan Wang ◽

Xiaowei Deng ◽

Song Pang ◽

Jian Liu ◽

...

Keyword(s):

Dynamic Response ◽

Membrane Structure ◽

Impact Analysis ◽

Impact Load ◽

Dynamic Responses ◽

Flexible Structure ◽

Membrane Material ◽

Membrane Structures ◽

Characteristic Points ◽

The Impact

The membrane structure is a flexible structure, which is easy to vibrate or even relax under dynamic load. Engineering accident analysis shows that the relaxation of membrane structure is more likely to lead to structural failure. In this article, the impact load problem is combined with the flexible structure to analyze the impact of hailstone impact load on the dynamic response of membrane structure. First, the umbrella membrane stretching device was designed and manufactured, and the hailstone impact test was carried out on the umbrella membrane structure with polyvinyl chloride membrane material. Dynamic response data, tension relaxation of side cables and vibration deformation of umbrella membrane structures impacted by hailstones with different sizes and different characteristic points were obtained. In the numerical analysis, the form-finding analysis of umbrella membrane structure is carried out by finite element method, and the transient impact analysis is conducted in LS-DYNA. Finally, the reliability of the research results is verified by comparing the numerical and experimental results. The general laws and conclusions are drawn and the disaster-causing mechanism of membrane structure impacted by hailstone is revealed. On the whole, although the probability of hailstone destroying the membrane material directly is very small, it will relax the membrane structure and affect the safety of membrane structure. The conclusions of this article provide a theoretical basis for the design and maintenance of membrane structures.

Download Full-text

Load and Response Identification for a Nonlinear Flexible Structure Subject to Harmonic Loads

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4025505 ◽

2013 ◽

Vol 9 (1) ◽

Cited By ~ 6

Author(s):

Maria Chierichetti

Keyword(s):

Dynamic Response ◽

Control Systems ◽

Numerical Approach ◽

Reference Points ◽

Structural Performance ◽

Flexible Structure ◽

Complete Structure ◽

Full Field ◽

Complete Knowledge ◽

Load Distributions

Experimental monitoring of dynamic response is generally limited to few locations in the system. However, the analysis of structural performance and design of control systems would benefit from a complete knowledge of the system dynamic during service. A numerical approach is developed to numerically reconstruct the load and response of a complete structure from few reference points, based on a modal approach for projecting the response at few points on the domain of the structure. This methodology is particularly advantageous when full-field monitoring of a structure is not a possible solution. An assembly of two beams joined by a nonlinear torsional spring is analyzed in case of different load distributions acting on its span. The approach is shown to be robust and reliable.

Download Full-text

Effects of Variations in Nonlinear Damping Coefficients on the Parametric Vibration of a Cantilever Beam with a Lumped Mass

Mathematical Problems in Engineering ◽

10.1155/2008/185351 ◽

2008 ◽

Vol 2008 ◽

pp. 1-19 ◽

Cited By ~ 2

Author(s):

Demian G. Silva ◽

Paulo S. Varoto

Keyword(s):

Energy Dissipation ◽

Dynamic Response ◽

Cantilever Beam ◽

Drag Force ◽

Perturbation Technique ◽

Experimental Results ◽

Flexible Structure ◽

Lumped Mass ◽

Force Coefficient ◽

Quadratic Damping

Uncertainties in damping estimates can significantly affect the dynamic response of a given flexible structure. A common practice in linear structural dynamics is to consider a linear viscous damping model as the major energy dissipation mechanism. However, it is well known that different forms of energy dissipation can affect the structure's dynamic response. The major goal of this paper is to address the effects of the turbulent frictional damping force, also known as drag force on the dynamic behavior of a typical flexible structure composed of a slender cantilever beam carrying a lumped-mass on the tip. First, the system's analytical equation is obtained and solved by employing a perturbation technique. The solution process considers variations of the drag force coefficient and its effects on the system's response. Then, experimental results are presented to demonstrate the effects of the nonlinear quadratic damping due to the turbulent frictional force on the system's dynamic response. In particular, the effects of the quadratic damping on the frequency-response and amplitude-response curves are investigated. Numerically simulated as well as experimental results indicate that variations on the drag force coefficient significantly alter the dynamics of the structure under investigation.

Download Full-text