**Commenced**in January 2007

**Frequency:**Monthly

**Edition:**International

**Paper Count:**479

# Search results for: cantilever beam.

##### 479 Vibration Control of a Cantilever Beam Using a Tunable Vibration Absorber Embedded with ER Fluids

**Authors:**
Chih-Jer Lin,
Chun-Ying Lee,
Chiang-Ho Cheng,
Geng-Fung Chen

**Abstract:**

This paper investigates experimental studies on vibration suppression for a cantilever beam using an Electro-Rheological (ER) sandwich shock absorber. ER fluid (ERF) is a class of smart materials that can undergo significant reversible changes immediately in its rheological and mechanical properties under the influence of an applied electric field. Firstly, an ER sandwich beam is fabricated by inserting a starch-based ERF into a hollow composite beam. At the same time, experimental investigations are focused on the frequency response of the ERF sandwich beam. Second, the ERF sandwich beam is attached to a cantilever beam to become as a shock absorber. Finally, a fuzzy semi-active vibration control is designed to suppress the vibration of the cantilever beam via the ERF sandwich shock absorber. To check the consistency of the proposed fuzzy controller, the real-time implementation validated the performance of the controller.

**Keywords:**
Electro-Rheological Fluid,
Semi-active vibration
control,
shock absorber,
fuzzy control,
Real-time control.

##### 478 Nonlinear Finite Element Analysis of Composite Cantilever Beam with External Prestressing

**Authors:**
R. I. Liban,
N. Tayşi

**Abstract:**

This paper deals with a nonlinear finite element analysis to examine the behavior up to failure of cantilever composite steel-concrete beams which are prestressed externally. 'Pre-' means stressing the high strength external tendons in the steel beam section before the concrete slab is added. The composite beam contains a concrete slab which is connected together with steel I-beam by means of perfect shear connectors between the concrete slab and the steel beam which is subjected to static loading. A finite element analysis will be done to study the effects of external prestressed tendons on the composite steel-concrete beams by locating the tendons in different locations (profiles). ANSYS version 12.1 computer program is being used to analyze the represented three-dimensional model of the cantilever composite beam. This model gives all these outputs, mainly load-displacement behavior of the cantilever end and in the middle span of the simple support part.

**Keywords:**
Composite steel-concrete beams,
external prestressing,
finite element analysis,
ANSYS.

##### 477 Elastic Stress Analysis of Composite Cantilever Beam Loaded Uniformly

**Authors:**
A. Kurşun,
M. Tunay Çetin,
E. Çetin,
H. Aykul

**Abstract:**

In this investigation an elastic stress analysis is carried out a woven steel fiber reinforced thermoplastic cantilever beam loaded uniformly at the upper surface. The composite beam material consists of low density polyethylene as a thermoplastic (LDFE, f.2.12) and woven steel fibers. Granules of the polyethylene are put into the moulds and they are heated up to 160°C by using electrical resistance. Subsequently, the material is held for 5min under 2.5 MPa at this temperature. The temperature is decreased to 30°C under 15 MPa pressure in** 3**min. Closed form solution is found satisfying both the governing differential equation and boundary conditions. We investigated orientation angle effect on stress distribution of composite cantilever beams. The results show that orientation angle play an important role in determining the responses of a woven steel fiber reinforced thermoplastic cantilever beams and an optimal design of these structures.

**Keywords:**
Cantilever beam,
elastic stress analysis,
orientation angle,
thermoplastic.

##### 476 Notes on Vibration Design for Piezoelectric Cooling Fan

**Authors:**
Thomas Jin-Chee Liu,
Yu-Shen Chen,
Hsi-Yang Ho,
Jyun-Ting Liu,
Chih-Chun Lee

**Abstract:**

This paper discusses some notes on the vibration design for the piezoelectric cooling fan. After reviewing the fundamental formulas of the cantilever Euler beam, it is not easy to find the optimal design of the piezoelectric fan. The experiments also show the complicated results of the vibration behavior and air flow.

**Keywords:**
Piezoelectric cooling fan,
vibration,
cantilever Euler beam,
air flow.

##### 475 Design and Analysis of a Piezoelectric-Based AC Current Measuring Sensor

**Authors:**
Easa Ali Abbasi,
Akbar Allahverdizadeh,
Reza Jahangiri,
Behnam Dadashzadeh

**Abstract:**

Electrical current measurement is a suitable method for the performance determination of electrical devices. There are two contact and noncontact methods in this measuring process. Contact method has some disadvantages like having direct connection with wire which may endamage the system. Thus, in this paper, a bimorph piezoelectric cantilever beam which has a permanent magnet on its free end is used to measure electrical current in a noncontact way. In mathematical modeling, based on Galerkin method, the governing equation of the cantilever beam is solved, and the equation presenting the relation between applied force and beam’s output voltage is presented. Magnetic force resulting from current carrying wire is considered as the external excitation force of the system. The results are compared with other references in order to demonstrate the accuracy of the mathematical model. Finally, the effects of geometric parameters on the output voltage and natural frequency are presented.

**Keywords:**
Cantilever beam,
electrical current measurement,
forced excitation,
piezoelectric.

##### 474 An Experimental Study of Downstream Structures on the Flow-Induced Vibrations Energy Harvester Performances

**Authors:**
Pakorn Uttayopas,
Chawalit Kittichaikarn

**Abstract:**

This paper presents an experimental investigation for the characteristics of an energy harvesting device exploiting flow-induced vibration in a wind tunnel. A stationary bluff body is connected with a downstream tip body via an aluminium cantilever beam. Various lengths of aluminium cantilever beam and different shapes of downstream tip body are considered. The results show that the characteristics of the energy harvester’s vibration depend on both the length of the aluminium cantilever beam and the shape of the downstream tip body. The highest ratio between vibration amplitude and bluff body diameter was found to be 1.39 for an energy harvester with a symmetrical triangular tip body and L/D_{1} = 5 at 9.8 m/s of flow speed (Re = 20077). Using this configuration, the electrical energy was extracted with a polyvinylidene fluoride (PVDF) piezoelectric beam with different load resistances, of which the optimal value could be found on each Reynolds number. The highest power output was found to be 3.19 µW, at 9.8 m/s of flow speed (Re = 20077) and 27 MΩ of load resistance.

**Keywords:**
Downstream structures,
energy harvesting,
flow-induced vibration,
piezoelectric material,
wind tunnel.

##### 473 The Cracks Propagation Monitoring of a Cantilever Beam Using Modal Analysis

**Authors:**
Morteza Raki,
Abolghasem Zabihollah,
Omid Askari

**Abstract:**

**Keywords:**
Blade,
crack propagation,
health monitoring,
modal
analysis.

##### 472 An Approximate Lateral-Torsional Buckling Mode Function for Cantilever I-Beams

**Authors:**
H. Ozbasaran

**Abstract:**

**Keywords:**
Buckling mode,
cantilever,
lateral-torsional
buckling,
I-beam.

##### 471 Design and Development of Constant Stress Composite Cantilever Beam

**Authors:**
Vinod B. Suryawanshi,
Ajit D. Kelkar

**Abstract:**

Composite materials, due to their unique properties such as high strength to weight ratio, corrosion resistance, and impact resistance have huge potential as structural materials in automotive, construction and transportation applications. However, these properties often come at higher cost owing to complex design methods, difficult manufacturing processes and raw material cost. Traditionally, tapered laminated composite structures are manufactured using autoclave manufacturing process by ply drop off technique. Autoclave manufacturing though very powerful suffers from high capital investment and higher energy consumption. As per the current trends in composite manufacturing, Out of Autoclave (OoA) processes are looked as emerging technologies for manufacturing the structural composite components for aerospace and defense applications. However, there is a need for improvement among these processes to make them reliable and consistent. In this paper, feasibility of using out of autoclave process to manufacture the variable thickness cantilever beam is discussed. The minimum weight design for the composite beam is obtained using constant stress beam concept by tailoring the thickness of the beam. Ply drop off techniques was used to fabricate the variable thickness beam from glass/epoxy prepregs. Experiments were conducted to measure bending stresses along the span of the cantilever beam at different intervals by applying the concentrated load at the free end. Experimental results showed that the stresses in the bean at different intervals were constant. This proves the ability of OoA process to manufacture the constant stress beam. Finite element model for the constant stress beam was developed using commercial finite element simulation software. It was observed that the simulation results agreed very well with the experimental results and thus validated design and manufacturing approach used.

**Keywords:**
Beams,
Composites,
Constant Stress,
Structures.

##### 470 Vibration Control of a Functionally Graded Carbon Nanotube-Reinforced Composites Beam Resting on Elastic Foundation

**Authors:**
Gholamhosein Khosravi,
Mohammad Azadi,
Hamidreza Ghezavati

**Abstract:**

**Keywords:**
Carbon nanotubes,
vibration control,
piezoelectric layers,
elastic foundation.

##### 469 Improved Multi-Objective Particle Swarm Optimization Applied to Design Problem

**Authors:**
Kapse Swapnil,
K. Shankar

**Abstract:**

**Keywords:**
Utopia point,
multi-objective particle swarm optimization,
local search,
cantilever beam.

##### 468 Modal Analysis of a Cantilever Beam Using an Inexpensive Smartphone Camera: Motion Magnification Technique

**Authors:**
Hasan Hassoun,
Jaafar Hallal,
Denis Duhamel,
Mohammad Hammoud,
Ali Hage Diab

**Abstract:**

This paper aims to prove the accuracy of an inexpensive smartphone camera as a non-contact vibration sensor to recover the vibration modes of a vibrating structure such as a cantilever beam. A video of a vibrating beam is filmed using a smartphone camera and then processed by the motion magnification technique. Based on this method, the first two natural frequencies and their associated mode shapes are estimated experimentally and compared to the analytical ones. Results show a relative error of less than 4% between the experimental and analytical approaches for the first two natural frequencies of the beam. Also, for the first two-mode shapes, a Modal Assurance Criterion (MAC) value of above 0.9 between the two approaches is obtained. This slight error between the different techniques ensures the viability of a cheap smartphone camera as a non-contact vibration sensor, particularly for structures vibrating at relatively low natural frequencies.

**Keywords:**
Modal Analysis,
motion magnification,
smartphone camera,
structural vibration,
vibration modes.

##### 467 Simplified Equations for Rigidity and Lateral Deflection for Reinforced Concrete Cantilever Shear Walls

**Authors:**
Anas M. Fares

**Abstract:**

**Keywords:**
Cantilever shear walls,
flexural deformation,
lateral deflection,
lateral loads,
reinforced concrete shear walls,
rigidity,
shear deformation,
virtual work theorem.

##### 466 Active Control Improvement of Smart Cantilever Beam by Piezoelectric Materials and On-Line Differential Artificial Neural Networks

**Authors:**
P. Karimi,
A. H. Khedmati Bazkiaei

**Abstract:**

**Keywords:**
Smart material,
on-line differential artificial neural
network,
active control,
finite element method.

##### 465 Validity Domains of Beams Behavioural Models: Efficiency and Reduction with Artificial Neural Networks

**Authors:**
Keny Ordaz-Hernandez,
Xavier Fischer,
Fouad Bennis

**Abstract:**

In a particular case of behavioural model reduction by ANNs, a validity domain shortening has been found. In mechanics, as in other domains, the notion of validity domain allows the engineer to choose a valid model for a particular analysis or simulation. In the study of mechanical behaviour for a cantilever beam (using linear and non-linear models), Multi-Layer Perceptron (MLP) Backpropagation (BP) networks have been applied as model reduction technique. This reduced model is constructed to be more efficient than the non-reduced model. Within a less extended domain, the ANN reduced model estimates correctly the non-linear response, with a lower computational cost. It has been found that the neural network model is not able to approximate the linear behaviour while it does approximate the non-linear behaviour very well. The details of the case are provided with an example of the cantilever beam behaviour modelling.

**Keywords:**
artificial neural network,
validity domain,
cantileverbeam,
non-linear behaviour,
model reduction.

##### 464 Flexure of Cantilever Thick Beams Using Trigonometric Shear Deformation Theory

**Authors:**
Yuwaraj M. Ghugal,
Ajay G. Dahake

**Abstract:**

A trigonometric shear deformation theory for flexure of thick beams, taking into account transverse shear deformation effects, is developed. The number of variables in the present theory is same as that in the first order shear deformation theory. The sinusoidal function is used in displacement field in terms of thickness coordinate to represent the shear deformation effects. The noteworthy feature of this theory is that the transverse shear stresses can be obtained directly from the use of constitutive relations with excellent accuracy, satisfying the shear stress free conditions on the top and bottom surfaces of the beam. Hence, the theory obviates the need of shear correction factor. Governing differential equations and boundary conditions are obtained by using the principle of virtual work. The thick cantilever isotropic beams are considered for the numerical studies to demonstrate the efficiency of the. Results obtained are discussed critically with those of other theories.

**Keywords:**
Trigonometric shear deformation,
thick beam,
flexure,
principle of virtual work,
equilibrium equations,
stress.

##### 463 Development of a Sliding-tearing Mode Fracture Mechanical Tool for Laminated Composite Materials

**Authors:**
Andras Szekrenyes

**Abstract:**

This work presents the mixed-mode II/III prestressed split-cantilever beam specimen for the fracture testing of composite materials. In accordance with the concept of prestressed composite beams one of the two fracture modes is provided by the prestressed state of the specimen, and the other one is increased up to fracture initiation by using a testing machine. The novel beam-like specimen is able to provide any combination of the mode-II and mode-III energy release rates. A simple closed-form solution is developed using beam theory as a data reduction scheme and for the calculation of the energy release rates in the new configuration. The applicability and the limitations of the novel fracture mechanical test are demonstrated using unidirectional glass/polyester composite specimens. If only crack propagation onset is involved then the mixed-mode beam specimen can be used to obtain the fracture criterion of transparent composite materials in the GII - GIII plane in a relatively simple way.

**Keywords:**
Composite,
fracture mechanics,
toughness testing,
mixed-mode II/III fracture.

##### 462 Effect of Damping on Performance of Magnetostrictive Vibration Energy Harvester

**Authors:**
Mojtaba Ghodsi,
Hamidreza Ziaifar,
Morteza Mohammadzaheri,
Payam Soltani

**Abstract:**

This article presents an analytical model to estimate the harvested power from a Magnetostrictive cantilevered beam with tip excitation. Furthermore, the effects of internal and external damping on harvested power are investigated. The magnetostrictive material in this harvester is Galfenol. In comparison to other popular smart materials like Terfenol-D, Galfenol has higher strength and machinability. In this article, first, a mechanical model of the Euler-Bernoulli beam is employed to calculate the deflection of the harvester. Then, the magneto-mechanical equation of Galfenol is combined with Faraday's law to calculate the generated voltage of the Magnetostrictive cantilevered beam harvester. Finally, the beam model is incorporated in the aforementioned combination. The results show that a 30×8.5×1 mm Galfenol cantilever beam harvester with 80 turn pickup coil can generate up to 3.7 mV and 9 mW. Furthermore, sensitivity analysis made by Response Surface Method (RSM) shows that the harvested power is only sensitive to the internal damping coefficient.

**Keywords:**
Internal damping coefficient,
external damping coefficient,
Euler-Bernoulli,
energy harvester,
Galfenol,
magnetostrictive,
response surface method.

##### 461 Coupled Lateral-Torsional Free Vibrations Analysis of Laminated Composite Beam using Differential Quadrature Method

**Authors:**
S.H. Mirtalaie,
M. Mohammadi,
M.A. Hajabasi,
F.Hejripour

**Abstract:**

In this paper the Differential Quadrature Method (DQM) is employed to study the coupled lateral-torsional free vibration behavior of the laminated composite beams. In such structures due to the fiber orientations in various layers, the lateral displacement leads to a twisting moment. The coupling of lateral and torsional vibrations is modeled by the bending-twisting material coupling rigidity. In the present study, in addition to the material coupling, the effects of shear deformation and rotary inertia are taken into account in the definition of the potential and kinetic energies of the beam. The governing differential equations of motion which form a system of three coupled PDEs are solved numerically using DQ procedure under different boundary conditions consist of the combinations of simply, clamped, free and other end conditions. The resulting natural frequencies and mode shapes for cantilever beam are compared with similar results in the literature and good agreement is achieved.

**Keywords:**
Differential Quadrature Method,
Free vibration,
Laminated composite beam,
Material coupling.

##### 460 Modeling and FOS Feedback Based Control of SISO Intelligent Structures with Embedded Shear Sensors and Actuators

**Authors:**
T. C. Manjunath,
B. Bandyopadhyay

**Abstract:**

**Keywords:**
Smart structure,
Timoshenko beam theory,
Fast output sampling feedback control,
Finite Element Method,
State space model,
SISO,
Vibration control,
LMI

##### 459 Robust Adaptive Vibration Control with Application to a Robot Beam

**Authors:**
J. Fei

**Abstract:**

**Keywords:**
finite element model,
adaptive control,
sliding modecontrol,
vibration suppression

##### 458 Influence of Wall Stiffness and Embedment Depth on Excavations Supported by Cantilever Walls

**Authors:**
Muhammad Naseem Baig,
Abdul Qudoos Khan,
Jamal Ali

**Abstract:**

Ground deformations in deep excavations are affected by wall stiffness and pile embedment ratio. This paper presents the findings of a parametric study of a 64-ft deep excavation in mixed stiff soil conditions supported by cantilever pile wall. A series of finite element analysis has been carried out in Plaxis 2D by varying the pile embedment ratio and wall stiffness. It has been observed that maximum wall deflections decrease by increasing the embedment ratio up to 1.50; however, any further increase in pile length does not improve the performance of the wall. Similarly, increasing wall stiffness reduces the wall deformations and affects the deflection patterns of the wall. The finite element analysis results are compared with the field data of 25 case studies of cantilever walls. Analysis results fall within the range of normalized wall deflections of the 25 case studies. It has been concluded that deep excavations can be supported by cantilever walls provided the system stiffness is increased significantly.

**Keywords:**
Excavations,
support systems,
wall stiffness,
cantilever walls.

##### 457 Control of Vibrations in Flexible Smart Structures using Fast Output Sampling Feedback Technique

**Authors:**
T.C. Manjunath,
B. Bandyopadhyay

**Abstract:**

**Keywords:**
Smart structure,
Finite element method,
State spacemodel,
Euler-Bernoulli theory,
SISO model,
Fast output sampling,
Vibration control,
LMI

##### 456 Critical Analysis of Different Actuation Techniques for a Micro Cantilever

**Authors:**
B. G. Sheeparamatti,
Prashant Hanasi,
Vanita Abbigeri

**Abstract:**

**Keywords:**
Actuation techniques,
microswitch,
micro actuator,
microsystems.

##### 455 Nonlinear Simulation of Harmonically Coupled Two-Beam Free-Electron Laser

**Authors:**
M. Zahedian,
B. Maraghechi,
M. H. Rouhani

**Abstract:**

**Keywords:**
Free-electron laser,
Higher energy beam,
Lowerenergy beam,
Two-beam

##### 454 Multivariable Control of Smart Timoshenko Beam Structures Using POF Technique

**Authors:**
T.C. Manjunath,
B. Bandyopadhyay

**Abstract:**

**Keywords:**
Smart structure,
Timoshenko theory,
Euler-Bernoulli
theory,
Periodic output feedback control,
Finite Element Method,
State space model,
Vibration control,
Multivariable system,
Linear
Matrix Inequality

##### 453 Investigation on an Innovative Way to Connect RC Beam and Steel Column

**Authors:**
Ahmed H. El-Masry,
Mohamed A. Dabaon,
Tarek F. El-Shafiey,
Abd El-Hakim A. Khalil

**Abstract:**

An experimental study was performed to investigate the behavior and strength of proposed technique to connect reinforced concrete (RC) beam to steel or composite columns. This approach can practically be used in several types of building construction. In this technique, the main beam of the frame consists of a transfer part (part of beam; Tr.P) and a common reinforcement concrete beam. The transfer part of the beam is connected to the column, whereas the rest of the beam is connected to the transfer part from each side. Four full-scale beam-column connections were tested under static loading. The test parameters were the length of the transfer part and the column properties. The test results show that using of the transfer part technique leads to modify the deformation capabilities for the RC beam and hence it increases its resistance against failure. Increase in length of the transfer part did not necessarily indicate an enhanced behavior. The test results contribute to the characterization of the connection behavior between RC beam - steel column and can be used to calibrate numerical models for the simulation of this type of connection.

**Keywords:**
Composite column,
reinforced concrete beam,
Steel
Column,
Transfer Part.

##### 452 Propagation of Cos-Gaussian Beam in Photorefractive Crystal

**Authors:**
A. Keshavarz

**Abstract:**

**Keywords:**
Beam propagation,
cos-Gaussian beam,
Numerical
simulation,
Photorefractive crystal.

##### 451 Controller Design for Euler-Bernoulli Smart Structures Using Robust Decentralized FOS via Reduced Order Modeling

**Authors:**
T.C. Manjunath,
B. Bandyopadhyay

**Abstract:**

**Keywords:**
Smart structure,
Euler-Bernoulli beam theory,
Fastoutput sampling feedback control,
Finite Element Method,
Statespace model,
Vibration control,
LMI,
Model order Reduction.

##### 450 Effect of Impact Location upon Sub-Impacts between Beam and Block

**Authors:**
T. F. Jin,
X. C. Yin,
P. B. Qian

**Abstract:**

**Keywords:**
Beam,
sub-impact,
substructure,
elastic-plasticity.