scholarly journals Simulation of an Adaptive Fluid-Membrane Piezoelectric Lens

Author(s):  
Hitesh Gowda Bettaswamy Gowda ◽  
Ulrike Wallrabe

In this paper, we present a finite element simulation of an adaptive piezoelectric fluid-membrane lens modeled in COMSOL Multiphysics. The simulation couples the piezoelectric effect with the fluid dynamics to model the interaction between piezoelectric forces and fluid forces. Also, the simulation is extended to model the thermal expansion of the fluid. Finally, we compare the simulation and experimental results of the adaptive lens refractive power at different actuation levels and temperatures.

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 797
Author(s):  
Hitesh Gowda Bettaswamy Bettaswamy Gowda ◽  
Ulrike Wallrabe

In this paper, we present a finite-element simulation of an adaptive piezoelectric fluid-membrane lens for which we modelled the fluid-structure interaction and resulting membrane deformation in COMSOL Multiphysics®. Our model shows the explicit coupling of the piezoelectric physics with the fluid dynamics physics to simulate the interaction between the piezoelectric and the fluid forces that contribute to the deformation of a flexible membrane in the adaptive lens. Furthermore, the simulation model is extended to describe the membrane deformation by additional fluid forces from the fluid thermal expansion. Subsequently, the simulation model is used to study the refractive power of the adaptive lens as a function of internal fluid pressure and analyze the effect of the fluid thermal expansion on the refractive power. Finally, the simulation results of the refractive power are compared to the experimental results at different actuation levels and temperatures validating the coupled COMSOL model very well. This is explicitly proven by explaining an observed positive drift of the refractive power at higher temperatures.


2014 ◽  
Vol 945-949 ◽  
pp. 1987-1990
Author(s):  
Si Quan Zhang ◽  
Yu Liu ◽  
Hao Jun Xu ◽  
Chang Yin

The structure of conventional bobbin probe was modified to improve the detection sensitivity of defects in metal tube. Based on the results of finite element simulation, several types of modified probes are fabricated and used to detect artificial defects in tube and the defect signals are acquired and analyzed. The simulation and experimental results verified that the modified eddy current probes are more sensitive to non-axial defects than conventional bobbin probe and can improve the reliability of tube inspection.


2007 ◽  
Vol 339 ◽  
pp. 276-280
Author(s):  
Y.T. Yu ◽  
Wei Zheng Yuan ◽  
D.Y. Qiao

Bifurcation of multi-layer microstructures subjected to thermal loading can be harmful for reliability and stability of MEMS structures. In this paper, three imperfections of geometry, coefficient of thermal expansion and thermal loading were introduced to investigate their effects on structural bifurcation by finite element simulation. Results show that bifurcation is strongly influenced by the imperfections. With larger deviation of imperfections, it results in a decreasing temperature to trigger the bifurcation and a gradual beginning of it.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3841 ◽  
Author(s):  
Zhang ◽  
Xiang ◽  
Wu ◽  
Feng ◽  
Shi ◽  
...  

Silicon carbide particle-reinforced aluminum matrix composite (SiCp/Al) has been widely used in the military and aerospace industry due to its special performance; however, there remain many problems in the processing. The present paper introduces an ultrasonic vibration tensile apparatus and a composite tensile specimen and performs Abaqus finite element simulation on high-volume SiCp/Al. The results show that the stress-strain curve increases linearly during conventional tensile strength; the intermittent vibration tensile strength is similar to the full course vibration tensile strength: The magnitude of the stress reduction increases as the amplitude of the ultrasound increases and the vibration frequency increases. The tensile rate is inversely proportional to the magnitude of the stress reduction, and in the ultrasonic parameters, the amplitude has the greatest influence on the magnitude of the stress reduction, followed by the tensile rate; additionally, the frequency has the least influence on the magnitude of the stress reduction. The experimental results show that the simulation results are consistent with the experimental results.


Author(s):  
J. Jerold John Britto ◽  
R. Venkatesh ◽  
K. Amudhan ◽  
A. Vasanthanathan ◽  
N. Gokulakrishnan ◽  
...  

2020 ◽  
Vol 90 (15-16) ◽  
pp. 1837-1850 ◽  
Author(s):  
Rimantas Barauskas ◽  
Audrone Sankauskaite ◽  
Vitalija Rubeziene ◽  
Ausra Gadeikyte ◽  
Virginija Skurkyte-Papieviene ◽  
...  

This study presents the developed computational finite element models for transient heat transfer analysis in fabrics enriched by phase change materials along with efforts to provide validation on the basis of obtained experimental results. The environment-friendly butyl stearate is used as a phase change material. Its melting/heating absorption takes place in temperature range from 19℃ to 34℃, and the solidification/heat release occurs from 34℃ to 19℃. An important aspect in this analysis is the investigation of appropriateness of the material samples dimensions selected for effective heat capacity against temperature measurements. For this purpose, we used the combined experimental and finite element simulation-based analysis. A similar computational procedure enabled us to estimate the effective latent specific heat relationship of the fabric with phase change materials coating. The direct usage of differential scanning calorimetry (DSC) measurement-based specific heat relationships against temperature in the finite element models ensured good compliance of the computed results with the experiment. For validation of the developed computational models the infrared radiation heating-cooling experiments on fabrics with different deposits of a phase change material were performed. The noticeable influence of content of phase change materials for transient thermal behavior during heating-cooling cycles was determined. The experimental results have been compared against the finite element simulation results.


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