Loading...
Search for:
damped-structures
0.005 seconds
Effects of viscoelastic supports on the behavior of bridges under moving vehicles
, Article Scientia Iranica ; Volume 24, Issue 4 , 2017 , Pages 1751-1769 ; 10263098 (ISSN) ; Vafai, H ; Sharif University of Technology
Sharif University of Technology
2017
Abstract
One of the most important problems facing structural engineers is the analysis of dynamic behavior of bridges subjected to moving vehicles. In addition, viscoelastic supports under bridges change their dynamic behavior under passing traffic loads. This paper presents how to model a bridge with viscoelastic supports and how the maximum dynamic stress of bridges changes during the passing of moving vehicles. Furthermore, this paper presents an algorithm to solve the governing equation of the bridge with viscoelastic supports as well as the equation of motion of a real European truck with different speeds, simultaneously. Using viscoelastic supports with appropriate characteristics can make a...
Response Simulation of Non-Classically Damped Structures using Modal and Stochastic Subspace Identification
, M.Sc. Thesis Sharif University of Technology ; Ahmadizadeh, Mehdi (Supervisor)
Abstract
As more structures are equipped with supplemental energy dissipation devices, the assumption of classical damping becomes less accurate. For this reason, development of a general identification method that is accurate enough for response simulation is emparative for such structures. Modal identification of structures can be carried out using either modal or state space approach. In modal methods (such as wavelet transform method), the damping matrix needs to be identified for response simulation. This is sometimes difficult, and may result in simulation inaccuracies. In contrast, direct identification of damping matrix for simulation is not required in state space approach. Hence, the...
Robust flutter analysis and control of a wing
, Article Aircraft Engineering and Aerospace Technology ; Volume 84, Issue 6 , 2012 , Pages 423-438 ; 00022667 (ISSN) ; Moghaddam, M ; Rahim, M ; Sharif University of Technology
2012
Abstract
Purpose - The purpose of this paper is to present a novel approach in aeroservoelastic analysis and robust control of a wing section with two control surfaces in leading-edge and trailing-edge. The method demonstrates how the number of model uncertainties can affect the flutter margin. Design/methodology/approach - The proposed method effectively incorporates the structural model of a wing section with two degrees of freedom of pitch and plunge with two control surfaces on trailing and leading edges. A quasi-steady aerodynamics assumption is made for the aerodynamic modeling. Basically, perturbations are considered for the dynamic pressure models and uncertainty parameters are associated...