Protection of Continuous Structures Against Vibrations by Active Damping

1983 ◽  
Vol 105 (3) ◽  
pp. 374-381
Author(s):  
E. Luzzato ◽  
M. Jean
Keyword(s):  
Control System ◽  
Mechanical Model ◽  
Approximation Problem ◽  
Active Damping ◽  
Simply Supported ◽  
Viscoelastic Structure ◽  
Flexural Vibrations ◽  
Dimension Space ◽  
Damping Of Vibrations ◽  
General Method

In this paper, we deal with the problem of active damping of vibrations of a continuous viscoelastic structure, and a general method of computation of the control system is developed. We define a mechanical model for this structure, the sources of perturbing vibrations, the control system, and different absorption criteria. The problem is set in an infinite dimension space, and an approximation problem is derived in n dimension spaces. Two methods of resolution are proposed for this approximation problem, and the solutions are compared. An example is given for the case of flexural vibrations in beams. Numerical results simulating the behavior of flexural vibrations in a rectangular plate, which is simply supported along the whole boundary, are presented for three different absorption criteria, thus permitting a quick evaluation of the comparative effectiveness of the chosen criteria.

ANSYS Simply Supported Deep Beams Based on the Study of Mechanical Properties

2013 ◽  
Vol 351-352 ◽  
pp. 782-785
Author(s):  
Yong Bing Liu ◽  
Xiao Zhong Zhang
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Mechanical Model ◽  
Work Performance ◽  
Deep Beam ◽  
Analysis Software ◽  
Deep Beams ◽  
Element Analysis ◽  
Simply Supported ◽  
Force Characteristics

Established the mechanical model of simply supported deep beam, calculation and analysis of simple supported deep beams by using finite element analysis software ANSYS, simulated the force characteristics and work performance of the deep beam. Provides the reference for the design and construction of deep beams.

The Bending, Buckling, and Flexural Vibration of Simply Supported Polygonal Plates by Point-Matching

1961 ◽  
Vol 28 (2) ◽  
pp. 288-291 ◽  
Author(s):  
H. D. Conway
Keyword(s):  
Hydrostatic Pressure ◽  
Boundary Conditions ◽  
Flexural Vibration ◽  
Frequency Equation ◽  
Numerical Results ◽  
Special Technique ◽  
Point Matching ◽  
Buckling Loads ◽  
Simply Supported ◽  
Flexural Vibrations

The bending by uniform lateral loading, buckling by two-dimensional hydrostatic pressure, and the flexural vibrations of simply supported polygonal plates are investigated. The method of meeting the boundary conditions at discrete points, together with the Marcus membrane analog [1], is found to be very advantageous. Numerical examples include the calculation of the deflections and moments, and buckling loads of triangular square, and hexagonal plates. A special technique is then given, whereby the boundary conditions are exactly satisfied along one edge, and an example of the buckling of an isosceles, right-angled triangle plate is analyzed. Finally, the frequency equation for the flexural vibrations of simply supported polygonal plates is shown to be the same as that for buckling under hydrostatic pressure, and numerical results can be written by analogy. All numerical results agree well with the exact solutions, where the latter are known.

Study on Twin-Rotary Motion Control System Based on Siemens Technology CPU

2012 ◽  
Vol 229-231 ◽  
pp. 2201-2204
Author(s):  
Cun Hai Pan ◽  
Hui Li ◽  
Su Mei Du ◽  
Wei Gao
Keyword(s):  
Control System ◽  
Motion Control ◽  
Rotary Motion ◽  
Three Dimension ◽  
Motion Control System ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Dimension Space ◽  
The Cost

A twin-rotary motion control system was built based on a cam technology and Siemens S7-300T PLC in this paper. The system can position accurately in a three-dimension space using a twin-servo closed loop control system and can real-time monitor various parameters of positioning system by HMI (Human Machine Interface). It also can automatically collect various parameter information and judge the type of fault.At the same time, the degree of automation has been raised and the cost of production was reduced.

scholarly journals The Research on the Visual Obstacle-Avoidance Optimization in Robots Control

2013 ◽  
Vol 756-759 ◽  
pp. 372-375
Author(s):  
Hong Bin Tian
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Obstacle Avoidance ◽  
Visual Information ◽  
Structural Model ◽  
Three Dimension ◽  
Coordination Control ◽  
Dimension Space ◽  
The Mathematical Model ◽  
Very High

In order to increase the movement capability of the robotic visual system in three-dimension space, the paper designs an obstacle-avoidance algorithm based on robotic movement visual by effectively processing the visual information colleted by the robotics. This paper establishes a structural model of coordination control system. The obstacles can be effectively identified and avoided by the obstacle-avoidance theory in the robotics coordination operation. The mathematical model of the obstacle-avoidance algorithm can predict the locations of the obstacles. The experiment proves the proposed algorithm can avoid the obstacles in three-dimension space and the accuracy is very high.

Active Damping of Vibrations of a Cantilever Beam by Axial Force Control

2007 ◽  
Author(s):  
Thomas Pumho¨ssel ◽  
Horst Ecker
Keyword(s):  
Cantilever Beam ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Open Loop ◽  
Active Damping ◽  
Nonlinear Feedback ◽  
Euler Beam ◽  
Bending Vibrations ◽  
Loop Control ◽  
Damping Of Vibrations

In several fields, e.g. aerospace applications, robotics or the bladings of turbomachinery, the active damping of vibrations of slender beams which are subject to free bending vibrations becomes more and more important. In this contribution a slender cantilever beam loaded with a controlled force at its tip, which always points to the clamping point of the beam, is treated. The equations of motion are obtained using the Bernoulli-Euler beam theory and d’Alemberts principle. To introduce artificial damping to the lateral vibrations of the beam, the force at the tip of the beam has to be controlled in a proper way. Two different methods are compared. One concept is the closed-loop control of the force. In this case a nonlinear feedback control law is used, based on axial velocity feedback of the tip of the beam and a state-dependent amplification. By contrast, the concept of open-loop parametric control works without any feedback of the actual vibrations of the mechanical structure. This approach applies the force as harmonic function of time with constant amplitude and frequency. Numerical results are carried out to compare and to demonstrate the effectiveness of both methods.

scholarly journals An active damping vibration control system for wind tunnel models

2019 ◽  
Vol 32 (9) ◽  
pp. 2109-2120 ◽  
Author(s):  
Wei LIU ◽  
Mengde ZHOU ◽  
Zhengquan WEN ◽  
Zhuang YAO ◽  
Yu LIU ◽  
...  
Keyword(s):  
Control System ◽  
Wind Tunnel ◽  
Vibration Control ◽  
Active Damping

Limit Analysis and Yield-Line Theory

1968 ◽  
Vol 35 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Antoni Sawczuk ◽  
P. G. Hodge
Keyword(s):  
Limit Analysis ◽  
Single Point ◽  
Point Load ◽  
Simply Supported ◽  
Yield Line ◽  
Yield Line Theory ◽  
Line Theory ◽  
The Relationship ◽  
Line Analysis ◽  
General Method

The relationship between limit analysis and yield-line analysis is investigated. Attention is restricted to simply supported, isotropic slabs subjected to single-point loadings. It is found that conventional yield-line analyses quite often give substantial overestimates of the carrying capacity. A general method is formulated for finding the yield-point load, and various examples are considered.

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