scholarly journals A Numerical Method of the Euler-Bernoulli Beam with Optimal Local Kelvin-Voigt Damping

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Xin Yu ◽  
Zhigang Ren ◽  
Qian Zhang ◽  
Chao Xu
Keyword(s):  
Control Problem ◽  
Numerical Approximation ◽  
Optimal Parameter ◽  
Nonlinear Coefficient ◽  
Programming Algorithm ◽  
Beam Equation ◽  
Control Input ◽  
Bernoulli Beam ◽  
Finite Dimensional ◽  
Euler Bernoulli Beam

This paper deals with the numerical approximation problem of the optimal control problem governed by the Euler-Bernoulli beam equation with local Kelvin-Voigt damping, which is a nonlinear coefficient control problem with control constraints. The goal of this problem is to design a control input numerically, which is the damping and distributes locally on a subinterval of the region occupied by the beam, such that the total energy of the beam and the control on a given time period is minimal. We firstly use the finite element method (FEM) to obtain a finite-dimensional model based on the original PDE system. Then, using the control parameterization method, we approximate the finite-dimensional problem by a standard optimal parameter selection problem, which is a suboptimal problem and can be solved numerically by nonlinear mathematical programming algorithm. At last, some simulation studies will be presented by the proposed numerical approximation method in this paper, where the damping controls act on different locations of the Euler-Bernoulli beam.

scholarly journals Application of ADM Using Laplace Transform to Approximate Solutions of Nonlinear Deformation for Cantilever Beam

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Ratchata Theinchai ◽  
Siriwan Chankan ◽  
Weera Yukunthorn
Keyword(s):  
Laplace Transform ◽  
Cantilever Beam ◽  
Adomian Decomposition Method ◽  
Small Deformation ◽  
Approximate Solutions ◽  
Beam Equation ◽  
Bernoulli Beam ◽  
Initial Value ◽  
Adomian Decomposition ◽  
Euler Bernoulli Beam

We investigate semianalytical solutions of Euler-Bernoulli beam equation by using Laplace transform and Adomian decomposition method (LADM). The deformation of a uniform flexible cantilever beam is formulated to initial value problems. We separate the problems into 2 cases: integer order for small deformation and fractional order for large deformation. The numerical results show the approximated solutions of deflection curve, moment diagram, and shear diagram of the presented method.

Sliding Mode Control for a Membrane Mirror Strip Actuated Using Multiple Smart Actuators

2007 ◽  
Author(s):  
Jamil M. Renno ◽  
C. Konda Reddy ◽  
Daniel J. Inman ◽  
Eric J. Ruggiero
Keyword(s):  
Sliding Mode ◽  
Fiber Composite ◽  
Tensile Load ◽  
Control Law ◽  
Bernoulli Beam ◽  
Finite Dimensional ◽  
Dimensional State Space ◽  
Euler Bernoulli Beam ◽  
Mode Technique ◽  
Membrane Strip

The sliding mode technique is used to control the deformation of a membrane mirror strip. A membrane mirror strip is augmented with two macro fiber composite (MFC) bimorphs. The first bimorph is actuated in bending whereas the second is actuated in tension. Membrane strips are usually tensioned uniformly. However, the presence of the tension bimorphs induces a local tension at its location. The membrane strip is modeled as an Euler-Bernoulli beam under tensile load, whereas the MFCs are modeled as monolithic piezoceramics. To cast the system into a finite dimensional state space form, the finite elements method (FEM) is used. The control action is switched when the membrane strip approaches its original undeformed shape. Simulation results demonstrate the effectiveness of the proposed control law.

Comparison of Methods for Modeling a Hydraulic Loader Crane With Flexible Translational Links

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Henrik C. Pedersen ◽  
Torben O. Andersen ◽  
Brian K. Nielsen
Keyword(s):  
Order Approximation ◽  
Mode Shapes ◽  
Beam Equation ◽  
Flexible Structure ◽  
Bernoulli Beam ◽  
Finite Segment ◽  
Single Beam ◽  
Beam Elements ◽  
Euler Bernoulli Beam ◽  
Mode Order

When modeling flexible robots and structures for control purposes, most often the assumed modes (AMs) method is used to describe the deformation in combination with a floating reference frame formulation. This typically has the benefit of obtaining a low-order, but accurate model of the flexible structure, if the number of modes and AMs are properly chosen. The basis for using this method is, however, that the vibrations (deflections) are time and position independent, i.e., the expression is separable in space and time. This holds for the classic Euler–Bernoulli beam equation, but essentially does not hold for translational links. Hence, special care has to be taken when including flexible translational links. In the current paper, different methods for modeling a hydraulic loader crane with a telescopic arm are investigated and compared using both the finite segment (FS) and AMs method. The translational links are approximated by a single beam, respectively, multiple beam elements, with both one and two modes and using different mode shapes. The models are all validated against experimental data and the comparison is made for different operating scenarios. Based on the results, it is found that in most cases a single beam, low mode order approximation is sufficient to accurately model the mechanical structure and this yields similar results as the FS method.

Noether Symmetry Analysis of the Dynamic Euler-Bernoulli Beam Equation

2016 ◽  
Vol 71 (5) ◽  
pp. 447-456 ◽  
Author(s):  
A.G. Johnpillai ◽  
K.S. Mahomed ◽  
C. Harley ◽  
F.M. Mahomed
Keyword(s):  
Conservation Laws ◽  
Power Law ◽  
Numerical Solutions ◽  
Noether Symmetry ◽  
Numerical Code ◽  
Beam Equation ◽  
Noether Symmetries ◽  
Bernoulli Beam ◽  
Symmetry Classification ◽  
Euler Bernoulli Beam

AbstractWe study the fourth-order dynamic Euler-Bernoulli beam equation from the Noether symmetry viewpoint. This was earlier considered for the Lie symmetry classification. We obtain the Noether symmetry classification of the equation with respect to the applied load, which is a function of the dependent variable of the underlying equation. We find that the principal Noether symmetry algebra is two-dimensional when the load function is arbitrary and extends for linear and power law cases. For all cases, for each of the Noether symmetries associated with the usual Lagrangian, we construct conservation laws for the equation via the Noether theorem. We also provide a basis of conservation laws by using the adjoint algebra. The Noether symmetries pick out the special value of the power law, which is –7. We consider the Noether symmetry reduction for this special case, which gives rise to a first integral that is used for our numerical code. For this, we then find numerical solutions using an in-built function in MATLAB called bvp4c, which is a boundary value solver for differential equations that are depicted in five figures. The physical solutions obtained are for the deflection of the beam with an increase in displacement. These are given in four figures and discussed.

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