scholarly journals A Novel Solution to Find the Dynamic Response of an Euler–Bernoulli Beam Fitted with Intraspan TMDs under Poisson Type Loading

2020 ◽  
Vol 5 (5) ◽  
pp. 40
Author(s):  
Alberto Di Matteo ◽  
Iain Peter Dunn ◽  
Giuseppe Failla ◽  
Antonina Pirrotta
Keyword(s):  
Smart Devices ◽  
Bernoulli Beam ◽  
Eigenvalues And Eigenfunctions ◽  
Traffic Loading ◽  
Vibrational Response ◽  
Complex Eigenvalues ◽  
Real World Applications ◽  
Euler Bernoulli Beam ◽  
Theory Of Generalized Functions ◽  
Poisson Type

This contribution considers a virtual experiment on the vibrational response of rail and road bridges equipped with smart devices in the form of damping elements to mitigate vibrations. The internal damping of the bridge is considered a discontinuity that contain a dashpot. Exact complex eigenvalues and eigenfunctions are derived from a characteristic equation built as the determinant of a 4 × 4 matrix; this is accomplished through the use of the theory of generalized functions to find the response variables at the positions of the damping elements. To relate this to real world applications, the response of a bridge under Poisson type white noise is evaluated; this is similar to traffic loading that would be seen in a bridge’s service life. The contribution also discusses the importance of smart damping and dampers to sustainability efforts through the reduction of required materials, and it discusses the role played by robust mathematical modelling in the design phase.

Vibrational response of coupled orthotropic protein microtubules immersed in cytosol considering small-scale and surface effects

2017 ◽  
Vol 231 (3) ◽  
pp. 131-139
Author(s):  
A Ghorbanpour Arani ◽  
E Haghparast ◽  
Z Khoddami Maraghi
Keyword(s):  
Timoshenko Beam ◽  
Elasticity Modulus ◽  
Surface Elasticity ◽  
Nonlocal Theory ◽  
Small Scale ◽  
Bernoulli Beam ◽  
Scale Parameters ◽  
Vibrational Response ◽  
Euler Bernoulli Beam ◽  
Filament Network

In this research, orthotropic Euler–Bernoulli beam and Timoshenko beam models are developed to investigate vibrational behavior of coupled protein microtubules. Microtubules are hollow cylindrical filaments in the living cells which are surrounded by filament network, which is simulated by Winkler–Riley Model. Temperature-dependent material properties for microtubules are used to study the thermal effect on vibration frequency. To apply the size effect, nonlocal theory is utilized, and the motion equations are derived based on Hamilton’s principle. In order to examine reliability of presented study, effects of various parameters such as environmental conditions, temperature change, boundary conditions and small-scale parameters on vibration characteristics of isotropic and orthotropic microtubules for both Euler–Bernoulli beam and Timoshenko beam models are discussed in detail. Results revealed that dynamic behavior of coupled microtubules is strongly dependent on the surface elasticity modulus of cytosol, so that, increasing surface elasticity modulus leads to increase in frequency of coupled microtubules. Results of this investigation can be provided as a useful reference in bio-medical clinical application.

LMI-based hybrid temporal-spatial differential control design for a class of Euler-Bernoulli beam system

2021 ◽  
pp. 095440622110036
Author(s):  
Jiaqi Zhong ◽  
Xiaolei Chen ◽  
Yupeng Yuan ◽  
Jiajia Tan
Keyword(s):  
Vibration Suppression ◽  
Direct Method ◽  
Recursive Algorithm ◽  
Linear Matrix ◽  
Bernoulli Beam ◽  
Hybrid Controller ◽  
Beam System ◽  
Active Vibration ◽  
Differential Control ◽  
Euler Bernoulli Beam

This paper addresses the problem of active vibration suppression for a class of Euler-Bernoulli beam system. The objective of this paper is to design a hybrid temporal-spatial differential controller, which is involved with the in-domain and boundary actuators, such that the closed-loop system is stable. The Lyapunov’s direct method is employed to derive the sufficient condition, which not only can guarantee the stabilization of system, but also can improve the spatial cooperation of actuators. In the framework of the linear matrix inequalities (LMIs) technology, the gain matrices of hybrid controller can obtained by developing a recursive algorithm. Finally, the effectiveness of the proposed methodology is demonstrated by applying a numerical simulation.

Employing Surface Roughness for Bridge-Vehicle Interaction Based Damage Detection

2011 ◽  
Author(s):  
Vesna Jaksic ◽  
Vikram Pakrashi ◽  
Alan O’Connor
Keyword(s):  
Surface Roughness ◽  
Damage Detection ◽  
Flexural Rigidity ◽  
Single Point ◽  
Point Load ◽  
Ride Quality ◽  
Breathing Crack ◽  
Bernoulli Beam ◽  
Statistical Parameters ◽  
Euler Bernoulli Beam

Damage detection and Structural Health Monitoring (SHM) for bridges employing bridge-vehicle interaction has created considerable interest in recent times. In this regard, a significant amount of work is present on the bridge-vehicle interaction models and on damage models. Surface roughness on bridges is typically used for detailing models and analyses are present relating surface roughness to the dynamic amplification of response of the bridge, the vehicle or to the ride quality. This paper presents the potential of using surface roughness for damage detection of bridge structures through bridge-vehicle interaction. The concept is introduced by considering a single point observation of the interaction of an Euler-Bernoulli beam with a breathing crack traversed by a point load. The breathing crack is treated as a nonlinear system with bilinear stiffness characteristics related to the opening and closing of crack. A uniform degradation of flexural rigidity of an Euler-Bernoulli beam traversed by a point load is also considered in this regard. The surface roughness of the beam is essentially a spatial representation of some spectral definition and is treated as a broadband white noise in this paper. The mean removed residuals of beam response are analyzed to estimate damage extent. Uniform velocity and acceleration conditions of the traversing load are investigated for the appropriateness of use. The detection and calibration of damage is investigated through cumulant based statistical parameters computed on stochastic, normalized responses of the damaged beam due to passages of the load. Possibilities of damage detection and calibration under benchmarked and non-benchmarked cases are discussed. Practicalities behind implementing this concept are also considered.

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