Finite Element Numerical Analysis of Deflection Behavior in Photostrictive Actuators on Overhanging and Propped Cantilever Beam Models

2017 ◽  
Author(s):  
Mosfequr Rahman ◽  
Hunter Taylor ◽  
Abdur Rahman ◽  
Gustavo Molina
Keyword(s):  
Finite Element ◽  
Light Intensity ◽  
Cantilever Beam ◽  
Photovoltaic Effect ◽  
Ferroelectric Ceramics ◽  
Beam Model ◽  
Element Analysis ◽  
Mems Technology ◽  
Converse Piezoelectric Effect ◽  
Transverse Deflection

Photostriction is best defined as the generation of strain in a material via light irradiation. In essence the photostrictive effect is a result of the combination of the photovoltaic and converse-piezoelectric effects. When light comes into contact with the surface of a photostrictive material, the photovoltaic effect causes the generation of a large amount of voltage. The converse-piezoelectric effect in turn converts the produced voltage into mechanical motion, which induces strain in the material. Photostrictive ceramics are considered excellent materials for use in advanced actuation technologies. This is due to their ability to be activated through irradiation of light, which provides advantages over conventional actuators, which include remote control capability, freedom from physical actuation, and reduced electromagnetic (EM) interference. Conversely conventional actuators require hard wired connections to transmit control signals that can produce EM interference, creating signal noise. Photostrictive ceramics have also found use in the manufacturing of micro electromechanical systems, also known as MEMS technology, mostly due to their wireless capabilities. Photostrictive materials are ferroelectric ceramics that exhibit the photostrictive effect. PLZT, (Pb, La)(Zr, Ti) O3 ceramics doped with WO3, exhibit large photostriction deflection under uniform illumination of light, and have potential uses in numerous micro-electro-mechanical systems as a result of this property. The objective of this research is to numerically investigate the effect of light intensity on transverse deflection of an overhanging beam model, and to assess the effect actuator size has on deflection for a propped cantilever beam model using finite element analysis technique. The current research results is then compared with the validated results of other studies on PLZT using other model types. From this numerical investigation it has been observed that for an overhanging beam model, the transverse deflection of PLZT actuators has a direct relationship to the intensity of the light applied in order to induce photostriction. It has also been observed that this relationship applies over a large range of light intensity upwards of 4000 mW/cm2, boosting maximum deflection into the micron range (1E−6 – 1E−7 m). With regard to the propped cantilever beam model, it has been observed that incomplete PLZT coverage of the cantilever beam portion of the model caused upwards transverse deflection. However, as the amount of PLZT actuator was increased, the deflection behavior exponentially approached negative values. By comparing these results with similar studies on alternate model types, it was confirmed that for beams deposited with PLZT actuator, light intensity and actuator size and surface coverage will affect the transverse deflection of the beam in the same manner regardless of the beam model.

Double Cantilever Beam Measurement and Finite Element Analysis of Cryogenic Mode I Interlaminar Fracture Toughness of Glass-Cloth/Epoxy Laminates

2000 ◽  
Vol 123 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Y. Shindo ◽  
K. Horiguchi ◽  
R. Wang ◽  
H. Kudo
Keyword(s):  
Fracture Toughness ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Cantilever Beam ◽  
Double Cantilever Beam ◽  
Mode I ◽  
Interlaminar Fracture Toughness ◽  
Element Analysis ◽  
Interlaminar Fracture ◽  
Delamination Crack

An experimental and analytical investigation in cryogenic Mode I interlaminar fracture behavior and toughness of SL-E woven glass-epoxy laminates was conducted. Double cantilever beam (DCB) tests were performed at room temperature (R.T.), liquid nitrogen temperature (77 K), and liquid helium temperature (4 K) to evaluate the effect of temperature and geometrical variations on the interlaminar fracture toughness. The fracture surfaces were examined by scanning electron microscopy to verify the fracture mechanisms. A finite element model was used to perform the delamination crack analysis. Critical load levels and the geometric and material properties of the test specimens were input data for the analysis which evaluated the Mode I energy release rate at the onset of delamination crack propagation. The results of the finite element analysis are utilized to supplement the experimental data.

Study on Flexibility of Intracranial Vascular Stents Based on the Finite Element Method

2018 ◽  
Vol 35 (4) ◽  
pp. 465-474 ◽  
Author(s):  
L. Liu ◽  
H. Jiang ◽  
Y. Dong ◽  
L. Quan ◽  
Y. Tong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cantilever Beam ◽  
Beam Model ◽  
The Finite Element Method ◽  
Simply Supported Beam ◽  
Bending Deformation ◽  
Vascular Stents ◽  
Simply Supported ◽  
Loading Method

ABSTRACTFlexibility is a particularly important biomechanical property for intracranial vascular stents. To study the flexibility of stent, the following work was carried out by using the finite element method: Four mechanical models were adopted to simulate the bending deformation of stents, and comparative studies were conducted about the distinction between cantilever beam and simply supported beam, as well as the distinction between moment-loading method and displacement-loading method. A complete process as implanting a stent including compressing, expanding and bending was also simulated, for analyzing the effects of compressing and expanding deformation on stent flexibility. At the same time, the effects of the arrangement and the number of bridges on stent flexibility were researched. The results show that: 1. A same flexibility index was obtained from cantilever beam model and simply supported beam model; displacement-loading method is better than moment-loading for simulating the bending deformation of stents. 2. The flexibility of stent with compressing and expanding deformation is lower than that in the initial form. 3. Crossly arranging the neighboring bridges in axial direction, can effectively improve the stent flexibility and reduce the flexibility difference in various bending directions; the bridge number, has proportional non-linear correlation with the stent rigidity as well as the maximum moment required for bending the stent.

scholarly journals Rapid Design and Analysis of Microtube Pneumatic Actuators Using Line-Segment and Multi-Segment Euler–Bernoulli Beam Models

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 780 ◽  
Author(s):  
Myunggi Ji ◽  
Qiang Li ◽  
In Ho Cho ◽  
Jaeyoun Kim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Line Segment ◽  
Beam Model ◽  
Element Analysis ◽  
Pneumatic Actuators ◽  
Design And Optimization ◽  
Rapid Design ◽  
The Finite Element Analysis ◽  
Soft Actuators

Soft material-based pneumatic microtube actuators are attracting intense interest, since their bending motion is potentially useful for the safe manipulation of delicate biological objects. To increase their utility in biomedicine, researchers have begun to apply shape-engineering to the microtubes to diversify their bending patterns. However, design and analysis of such microtube actuators are challenging in general, due to their continuum natures and small dimensions. In this paper, we establish two methods for rapid design, analysis, and optimization of such complex, shape-engineered microtube actuators that are based on the line-segment model and the multi-segment Euler–Bernoulli’s beam model, respectively, and are less computation-intensive than the more conventional method based on finite element analysis. To validate the models, we first realized multi-segment microtube actuators physically, then compared their experimentally observed motions against those obtained from the models. We obtained good agreements between the three sets of results with their maximum bending-angle errors falling within ±11%. In terms of computational efficiency, our models decreased the simulation time significantly, down to a few seconds, in contrast with the finite element analysis that sometimes can take hours. The models reported in this paper exhibit great potential for rapid and facile design and optimization of shape-engineered soft actuators.

Finite Element Analysis of Beam-Column Connection with Cantilever Beam Splicing

2013 ◽  
Vol 838-841 ◽  
pp. 540-544 ◽  
Author(s):  
Jian Rong Pan ◽  
Zhan Wang ◽  
Lin Qiang Zheng ◽  
Zheng Ting Yang
Keyword(s):  
Finite Element ◽  
Cantilever Beam ◽  
Welded Joint ◽  
Three Dimensional ◽  
Element Model ◽  
Rotational Stiffness ◽  
Element Analysis ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Three Dimensional Finite Element

Beam-column connection with cantilever beam bolted-splicing is also known as the joint of column-tree moment-resisting frame. The study is still relatively small for the semi-rigid behavior and rotational stiffness of the joint. This paper deal with four specimens of the joints with cantilever beam splicing and four specimens of the welded joints by using three dimensional finite element model analysis. The strain, stress, yield and ultimate loads, yield and ultimate deformations had been compared between the joint with cantilever beam splicing and the welded joint. The analysis results show that, when the splicing area of the joint with cantilever beam splicing was designed more strongly, the stress distribution, the load-displacement curves in elastic working stage, and the initial rotational stiffness are good agreement between the joint with cantilever beam splicing and the welded joint. The hysteresis curves of the joint with cantilever beam splicing were inverse S-shaped, indicating that there was greater slipping deformation because of bolt splicing. The welded joint had no slipping phenomenon.

Fabrication and Characteristics of Silicon Bridge Magnetic Sensor Based on Cantilever Beam

2014 ◽  
Vol 609-610 ◽  
pp. 1088-1093
Author(s):  
Lei Li ◽  
Xiao Feng Zhao ◽  
Yang Yu ◽  
Dian Zhong Wen ◽  
Jing Ya Cao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cantilever Beam ◽  
Thin Film Transistors ◽  
Wheatstone Bridge ◽  
Magnetic Sensor ◽  
Element Analysis ◽  
Microelectromechanical System ◽  
The Finite Element Analysis ◽  
Mems Technology ◽  
Simulation Results

A silicon bridge magnetic sensor based on cantilever beam is presented in this paper. Thesensor is composed of the Wheatstone bridge that made up of nano-polysilicon thin-film transistors(TFTs) and a ferromagnetic magnet adhered to the free end of cantilever beam. Through building thesimulation model, the finite element analysis of the sensor is carried out by using ANSYS software.The results show that this sensor can realize the measurement to the external magnetic field. Accordingto the simulation results, fabrication and packaging of the sensor chip are achieved by using the microelectromechanical system (MEMS) technology. Experiment result shows that when the supply voltageis 3.0 V, the sensitivity of the sensor is 94 mV/T.

Stiffness Analysis of Spot-Weld Specimen in Finite Element and Experimental Comparison

2011 ◽  
Vol 337 ◽  
pp. 564-569
Author(s):  
Hai Tao Yin ◽  
Tao Zhu ◽  
Bing Rong Miao
Keyword(s):  
Finite Element ◽  
Tensile Test ◽  
Simulation Models ◽  
Test Methods ◽  
Experimental Comparison ◽  
Beam Model ◽  
Element Analysis ◽  
Sus301l Stainless Steel ◽  
Finite Element Analysis Simulation ◽  
Tensile Forces

Three typical finite element models (FEM) of spot-welds have been created as analysis objects, and the relationship between force and displacement of the specimens were obtained under shear and tensile forces through the elastic-plastic finite element analysis. Simulation results and the shear-tensile test curves of TG301L and SUS301L stainless steel specimens which were obtained based on JIS Z 3136 shear-tensile test methods were compared. The results showed that: No matter what type of nuclear simulation, stiffness of simulation models are less than the actual stiffness of the specimen; and when the specimen was stretched and sheared, with solid element to simulate the nugget can get maximum stiffness, it is most close to the actual stiffness, umbrella model is followed, and a stiff beam model is the worst.

Experimental Investigation on the Use of Photostrictive Optical Actuator for MEMS Devices and Verification With the FEA Modeling Results

2011 ◽  
Author(s):  
Mosfequr Rahman ◽  
Masud Nawaz ◽  
John E. Jackson
Keyword(s):  
Thin Film ◽  
Lead Zirconate Titanate ◽  
Piezoelectric Effect ◽  
Photovoltaic Effect ◽  
Research Work ◽  
High Energy ◽  
Ferroelectric Ceramics ◽  
Control Signals ◽  
Fea Modeling ◽  
Converse Piezoelectric Effect

Photostrictive materials are lanthanum-modified lead zirconate titanate (Pb, La)(Zr, Ti) O3 ceramics doped with WO3, called PLZT, exhibit large photostriction under uniform illumination of high-energy light. Photostrictive materials are ferrodielectric ceramics that have a photostrictive effect. Photostriction arises from a superposition of the photovoltaic effect, i.e. the generation of large voltage from the irradiation of light, and the converse-piezoelectric effect, i.e. expansion or contraction under the voltage applied. When non-centrosymmetric materials, such as ferroelectric single crystals or polarized ferroelectric ceramics, are uniformly illuminated, a high voltage, considerably exceeding the band gap energy, is generated. Along with this photovoltage, mechanical strain is also induced due to the converse piezoelectric effect. Photostrictive materials offer the potential for actuators with many advantages over traditional transducing electromechanical actuators made of shape memory alloys and electroceramics (piezoelectric and electrostrictive). Drawback of traditional actuators is that they require hard-wired connections to transmit the control signals which introduce electrical noise into the control signals; on the other hand PLZT actuators offer non-contact actuation, remote control, and immune from electric/magnetic disturbances. Some experimental research has been conducted on the use of PLZT materials, such as optical motor as an electromechanical device suitable for miniaturization, micro-waking machine, photo driven relay device using PLZT bimorphs and high speed (less than 10 ns), low-voltage, low power consumption optical switch. Authors have developed a computational method and implemented in an in-house finite element code which will be useful for designing systems incorporating thin film photostrictive actuators. The purpose of this current research work is to design and develop an experimental test set-up for photostriction effect measurement of PLZT thin film of different thickness, size and location on silicon wafer as smart beams, which may be useful for various MEMS device as optical actuator. The experimental results will be verified by comparing with the FEA modeling results.

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