scholarly journals Comparative numerical studies of electromechanical finite element vibration power harvester approaches of a piezoelectric unimorph

Author(s):  
Ezi Warman ◽  
Mikail F. Lumentut ◽  
Ian M. Howard
2019 ◽  
Vol 221 ◽  
pp. 01003
Author(s):  
Pavel Radchenko ◽  
Stanislav Batuev ◽  
Andrey Radchenko

The paper presents results of applying approach to simulation of contact surfaces fracture under high velocity interaction of solid bodies. The algorithm of erosion -the algorithm of elements removing, of new surface building and of mass distribution after elements fracture at contact boundaries is consider. The results of coordinated experimental and numerical studies of fracture of materials under impact are given. Authors own finite element computer software program EFES, allowing to simulate a three-dimensional setting behavior of complex structures under dynamic loads, has been used for the calculations.


2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.


2018 ◽  
Vol 251 ◽  
pp. 04007 ◽  
Author(s):  
Vadim Alpatov ◽  
Alexey Lukin ◽  
Irina Laguta

The program «Gofro» is intended for the automated generation of data on the geometrical scheme of the beam with corrugated or plane web for further use in design complexes. The program has got a window interface, and it consists of one module for the input of feed da-ta, for calculation and for the display of its results in txt file format. The program offers a possibility to choose the outline of the structure, the profile of the web, the type of cross-section, and to set other parameters of the structure. When building up the model with the help of the author program «Gofro» and GMSH preprocessor for the automatic genera-tion of finite element mesh, the correctness of geometrical shape of elements is monitored by the algorithms that are input in the preprocessor. The author compares the time re-quired to create the models using the author program and GMSH preprocessor and using the standard resources of «Lira» software system. The authors performed numerical studies of various I-beams created in the program «GOPRO».


Biology ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 224
Author(s):  
María Prados-Privado ◽  
Carlos Martínez-Martínez ◽  
Sergio A. Gehrke ◽  
Juan Carlos Prados-Frutos

Bone plays an important role in dental implant treatment success. The goal of this literature review is to analyze the influence of bone definition and finite element parameters on stress in dental implants and bone in numerical studies. A search was conducted of Pubmed, Science Direct and LILACS, and two independent reviewers performed the data extraction. The quality of the selected studies was assessed using the Cochrane Handbook tool for clinical trials. Seventeen studies were included. Titanium was the most commonly-used material in dental implants. The magnitude of the applied loads varied from 15 to 300 N with a mean of 182 N. Complete osseointegration was the most common boundary condition. Evidence from this review suggests that bone is commonly defined as an isotropic material, despite being an anisotropic tissue, and that it is analyzed as a ductile material, instead of as a fragile material. In addition, and in view of the data analyzed in this review, it can be concluded that there is no standardization for conducting finite element studies in the field of dentistry. Convergence criteria are only detailed in two of the studies included in this review, although they are a key factor in obtaining accurate results in numerical studies. It is therefore necessary to implement a methodology that indicates which parameters a numerical simulation must include, as well as how the results should be analyzed.


2008 ◽  
Vol 583 ◽  
pp. 257-275 ◽  
Author(s):  
Ferdinando Auricchio ◽  
Alessandro Reali

The use of shape memory alloys (SMA) in an increasing number of applications in many ¯elds of engineering, such as biomedical engineering, is leading to a growing interest toward an exhaustive modeling of their macroscopic behavior in order to construct reliable simulation tools for SMA devices. In this paper we review a robust three-dimensional model able to reproduce both pseudo-elastic and shape-memory behaviors and we report numerical studies where it is used for the simulation of SMA-based biomedical devices.


2014 ◽  
Vol 599-601 ◽  
pp. 992-996
Author(s):  
Guo Jun Liu ◽  
Xue Lu Yang ◽  
Xu Hao Yang ◽  
Tian Zhao ◽  
Zhi Gang Yang ◽  
...  

The finite element model of a circular piezoelectric (PZT) unimorph actuator is set up, the static and dynamic characteristic of the circular PZT actuator are analyzed. For the investigated PZT actuator, comprehensive performance testing is carried out. Compared the simulation results of finite element method with experimental data, the central deflections of PZT actuator under the DC condition are same basically, the testing results show that the actual edge condition lies between clamped and pinned support. The impedance testing results of PZT actuators agree well with FEM analyses. Under AC condition, the central displacement which involves part of resonant component increases greatly by several times more than that under DC condition. While the displacement of actuator with resistance decreases greatly, and is slightly lower than that under DC condition. The relevant research methods lay foundation for the further study of PZT actuator under multi-field coupling condition. Key words: PZT actuator; Circular PZT unimorph; FEM; Static; Dynamic


1999 ◽  
Vol 10 (02n03) ◽  
pp. 485-500
Author(s):  
R. BARBERI ◽  
M. IOVANE ◽  
C. FERRERO ◽  
V. MOCELLA

This paper is devoted to numerical studies of two-dimensional problems concerning surface properties of nematic liquid crystals. We use a finite element method, based essentially on the classic variational approach, to find an approximate solution minimizing the Gibbs free energy of the nematic material under given boundary conditions. Three examples illustrate the performance and versatility of this analysis. Two cases are related to the macroscopic orientation induced by periodic boundary conditions: the first is a saw-toothed substrate in the micrometric range and the second is a microtextured surface. We analyze the bulk planar–homeotropic transition conditions for both of them. In the third case, we study the coupling between the spatial variation of the nematic director and that of the order parameter in the presence of surface-induced distortion.


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