Cantilevered Beams

2000 ◽  
pp. 163-207
Author(s):  
Marcio S. de Queiroz ◽  
Darren M. Dawson ◽  
Siddharth P. Nagarkatti ◽  
Fumin Zhang
Keyword(s):  
Cantilevered Beams

Mode coupling and locking of a Π-shaped cantilever resonator using laser-induced asymmetric modulation

2021 ◽  
Author(s):  
Wenyao Luo ◽  
Naikun Gao ◽  
Yanyan Li ◽  
Zhixin Zhao ◽  
Duo Liu
Keyword(s):  
Information Technology ◽  
Quality Factor ◽  
Mode Coupling ◽  
Microelectromechanical Systems ◽  
Mechanical Resonators ◽  
Signal To Noise ◽  
Resonant Frequencies ◽  
Asymmetric Modulation ◽  
Specific Geometry ◽  
Cantilevered Beams

Abstract Mechanical resonators, such as microcantilevers, demonstrate significant potential for use in information technology. Cantilevered beams of various geometries clamped at one end form the most ubiquitous structures in microelectromechanical systems (MEMSs) that support multimode vibration for the detection, conversion, and processing of small signals. In this study, we demonstrate that the potential of these devices can be further extended by utilizing a strategy based on mode coupling and locking induced by asymmetric photothermal modulation. A cantilever was designed to have a Π-shape with a specific geometry such that the resonant frequencies of the two orthogonal modes are close to one another. Additionally, we show that mode coupling between the two modes, which are originally orthogonal to one another, can be achieved through laser-induced photothermal modulation. In particular, the two modes can be parametrically tuned to become degenerate through mode coupling with a significant increase in the quality factor from 112 to 839. This approach is universal and can be extended to improve the detection limits of microresonators in high-dissipation environments with enhanced signal-to-noise ratios.

Influence of Adhesive Dimensions on the Transverse Free Vibration of Single-Lap Adhesive Cantilevered Beams

2011 ◽  
Vol 393-395 ◽  
pp. 149-152
Author(s):  
Bao Ying Xing ◽  
Xiao Cong He ◽  
Mo Sheng Feng
Keyword(s):  
Stress Concentration ◽  
Free Vibration ◽  
Dynamic Response ◽  
Significant Influence ◽  
Mode Shape ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Lap Joint ◽  
Adhesive Layers ◽  
Cantilevered Beams

This paper studies the influence of adhesive dimensions on the transverse free vibration of the single-lap adhesive cantilevered beams. The researches are performed by employing software ansys .Efficient analytic results of natural frequencies and mode shapes of transverse free vibration of the beams are provided, corresponding to different adhesive dimensions of bonded thicknesses and bondlines length. Bondlines length has more significant influence on the transverse natural frequencies and the lap joint’s mode shapes of the beams than bonded thickness. The transverse natural frequencies decrease with a decrease in the bondlines length of adhesive, but do not appear to variation observably with a decrease in the bonded thickness. Bondlines length shorting, the lap joint has a sharper mode shape. Simultaneously, the lap joint of even mode shapes influences the dynamic response of the beams significantly. These results indicate a local crack in adhesive layers because of the existence of stress concentration.

Bending of Iron-Gallium (Galfenol) Alloys for Sensor Applications

2005 ◽  
Vol 888 ◽  
Author(s):  
Patrick R. Downey ◽  
Alison B. Flatau
Keyword(s):  
Magnetic Signal ◽  
Sensor Applications ◽  
Bending Loads ◽  
Applied Forces ◽  
Gallium Alloys ◽  
Series Of Experiments ◽  
Magnetostrictive Sensor ◽  
Cantilevered Beams ◽  
Analytic Models ◽  
Iron Gallium

ABSTRACTThis project investigates the magnetomechanical sensing behavior of iron-gallium alloys in response to applied bending loads to identify the relevant design criteria for novel magnetostrictive sensor applications. A series of experiments are conducted on the magnetic induction response of cantilevered beams to dynamic bending loads. Analytic models of the system are formulated from both the constitutive magnetostriction equations and a free energy derivation. Both the experimental and analytical results show a change of as much as 0.3 T of induction can be measured in the samples in response to relatively small applied forces, with the output magnetic signal appearing at twice the frequency of beam vibration.

A Method for the Generation of Assumed Modes in Vibration Analysis

1970 ◽  
Vol 21 (3) ◽  
pp. 280-290 ◽  
Author(s):  
E. Nissim
Keyword(s):  
Boundary Conditions ◽  
Excellent Agreement ◽  
Vibration Analysis ◽  
Exact Methods ◽  
Arbitrary Boundary ◽  
Arbitrary Boundary Conditions ◽  
Methods Of Analysis ◽  
Cantilevered Beams

SummaryA method for the generation of assumed modes in beams with arbitrary boundary conditions is described. The method is applied to two cantilevered beams using a modified Rayleigh-Ritz vibration analysis. The results obtained show excellent agreement with those obtained by exact methods of analysis.

Influence of Mechanical Properties of Adhesives on Stress Distributions in Lap Joints

Volume 1 ◽  
2004 ◽  
Author(s):  
Xiaocong He ◽  
S. Olutunde Oyadiji
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Lap Joints ◽  
Stress Distributions ◽  
Element Analysis ◽  
Linear Elastic ◽  
Cantilevered Beam ◽  
Cantilevered Beams ◽  
Different Characteristics

This paper deals with stress analysis of a single lap-jointed cantilevered beam using the three dimensional linear elastic finite element analysis (FEA) technique. Numerical examples are provided to show the influence on the stresses of the single lap-jointed cantilevered beams using adhesives of different characteristics which encompass the entire spectrum of viscoelastic behaviour. The results indicate that the stress distributions of a single-lap jointed cantilevered beam are strongly affected by both Young’s modulus and Poisson’s ratios. The maximum stress ratio was used to determine maximum values of Young’s Modulus required in order that the static stresses of an adhesively bonded cantilevered beam will not be more than given value of that of the equivalent homogeneous structure, that is a geometrically similar beam but without a joint. The analysis results also show that by choosing suitable adhesives, the maximum stresses can be reduced and the strength can be improved.

scholarly journals A Broadband Vibration-Based Energy Harvester Using an Array of Piezoelectric Beams Connected by Springs

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
V. Meruane ◽  
K. Pichara
Keyword(s):  
Frequency Band ◽  
Energy Harvester ◽  
Experimental Measurements ◽  
Bernoulli Beam ◽  
Significant Drop ◽  
Energy Harvesters ◽  
Advantages And Disadvantages ◽  
Narrow Frequency Band ◽  
Cantilevered Beams ◽  
Euler Bernoulli Beam

Piezoelectric cantilevered beams have been widely used as vibration-based energy harvesters. Nevertheless, these devices have a narrow frequency band and if the excitation is slightly different there is a significant drop in the level of power generated. To handle this problem, the present investigation proposes the use of an array of piezoelectric cantilevered beams connected by springs as a broadband vibration-based energy harvester. The equations for the voltage and power output of the system are derived based on the analytical solution of the piezoelectric cantilevered energy harvester with Euler-Bernoulli beam assumptions. To study the advantages and disadvantages of the proposed system, the results are compared with those of an array of disconnected beams (with no springs). The analytical model is validated with experimental measurements of three bimorph beams with and without springs. The results show that connecting the array of beams with springs allows increasing the frequency band of operation and increasing the amount of power generated.

Electro-Rheological-Fluid-Based Articulating Robotic Systems

1989 ◽  
Vol 111 (3) ◽  
pp. 328-336 ◽  
Author(s):  
M. V. Gandhi ◽  
B. S. Thompson ◽  
S. B. Choi ◽  
S. Shakir
Keyword(s):  
High Strength ◽  
Theoretical Work ◽  
Robotic Systems ◽  
Advanced Materials ◽  
Superior Performance ◽  
Fluid Systems ◽  
Elastodynamic Response ◽  
Multiphase Fluid ◽  
Cantilevered Beams ◽  
New Research

The limitations of the current generation of robotic systems has triggered a new research thrust for predicting the elastodynamic response of assemblages of articulating flexible-bodied systems. This research thrust is extended herein by proposing the fabrication of robotic systems in either monolithic or ultra-advanced composite laminated high-strength, high-stiffness materials in which are incorporated electro-rheological fluids. These multiphase fluid systems, which change their rheological behavior instantaneously when subjected to an externally applied electrical field, provide a potential for tailoring the vibrational characteristics of these hybrid materials from which the structural members of the proposed robotic systems are fabricated. This paper is focused on developing the necessary design tools for predicting the vibrational response of flexible multibodied articulating systems fabricated with this new class of advanced materials. A variational theorem is developed herein as a basis for finite element formulations which can be employed to predict the elastodynamic response of these systems. A coherent combination of experimental and theoretical work on cantilevered beams is presented to demonstrate the viability of the proposed design methodology. In addition, computer simulation results are presented to demonstrate the potential payoffs in terms of superior performance characteristics of a new generation of robotic systems capitalizing on this innovative and revolutionary design philosophy.

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