VIBRATIONS ANALYSIS UNCOUPLED AND COUPLED FLUID-STRUCTURE BETWEEN SHELL AND ACOUSTIC CAVITY CYLINDRICAL FOR VARIOUS BOUNDARY CONDITIONS

2021 ◽  
pp. 399-409
Author(s):  
Davidson de Oliveira França Júnior ◽  
Lineu José Pedroso
Keyword(s):  
Boundary Conditions ◽  
Fluid Structure ◽  
Various Boundary Conditions ◽  
Acoustic Cavity

Fluid-Structure Interaction Simulation of Lactating Human Breast

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Jamasp Azarnoosh ◽  
Fatemeh Hassanipour
Keyword(s):  
Boundary Conditions ◽  
Flow Behavior ◽  
Fluid Structure Interaction ◽  
Ultrasound Images ◽  
Human Breast ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Various Boundary Conditions ◽  
Milk Flow ◽  
Maxilla And Mandible

Abstract This study presents a 3-D Fluid-Structure Interaction (FSI) simulation of breastfeeding mechanism to provide a better understanding of the milk flow behavior in the ductal system of the human breast as the breast interacts with the infant's oral cavity. The breast geometry consists of one lobe with three-bifurcation levels. The boundary conditions include: (1) The intraoral vacuum pressure, obtained from the clinical measurements, (2) Dynamic motion of the tongue, nipple, and jaw (maxilla and mandible) motion captured by ultrasound images. Simulation is conducted from the instance of latching and continues for two cycles of periodic tongue motion and in various boundary conditions and mouthing positions. The results from the simulation show that milk removal is not only due to the negative pressure applied by the infant sucking, but also the tongue movement and mouthing and squeezing of nipple and breast, i.e. a positive force deforming the nipple is responsible for the expression of milk. The developed model can contribute to a better understanding of breastfeeding complications due to physical infant and/or breast abnormalities and the design of medical devices such as artificial teats and breast pumps.

A simplified numerical and analytical study for assessing the seismic response of a gravity concrete lock

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Neander Berto Mendes ◽  
Lineu José Pedroso ◽  
Paulo Marcelo Vieira Ribeiro
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Study ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Fluid Structure ◽  
Analytical Formulation ◽  
Acoustic Cavity ◽  
Water Chamber ◽  
Structure Problem

ABSTRACT: This work presents the dynamic response of a lock subjected to the horizontal S0E component of the El Centro earthquake for empty and completely filled water chamber cases, by coupled fluid-structure analysis. Initially, the lock was studied by approximation, considering it similar to the case of a double piston coupled to a two-dimensional acoustic cavity (tank), representing a simplified analytical model of the fluid-structure problem. This analytical formulation can be compared with numerical results, in order to qualify the responses of the ultimate problem to be investigated. In all the analyses performed, modeling and numerical simulations were done using the finite element method (FEM), supported by the commercial software ANSYS.

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

Electro-osmotic chemical behavior of clayey soil under various boundary conditions

2021 ◽  
Vol 28 (5) ◽  
pp. 1493-1504
Author(s):  
Zhi-jia Xue ◽  
Qi Xiong
Keyword(s):  
Boundary Conditions ◽  
Clayey Soil ◽  
Chemical Behavior ◽  
Various Boundary Conditions

The Quasi-Static Analysis for Two-Dimensional Thin Plates

2011 ◽  
Vol 255-260 ◽  
pp. 166-169
Author(s):  
Li Chen ◽  
Yang Bai
Keyword(s):  
Boundary Conditions ◽  
Eigenfunction Expansion ◽  
Solution Space ◽  
Expansion Method ◽  
Fundamental Solutions ◽  
Thin Plates ◽  
Elastic Plates ◽  
Various Boundary Conditions ◽  
Eigenfunction Expansion Method ◽  
Concentration Phenomena

The eigenfunction expansion method is introduced into the numerical calculations of elastic plates. Based on the variational method, all the fundamental solutions of the governing equations are obtained directly. Using eigenfunction expansion method, various boundary conditions can be conveniently described by the combination of the eigenfunctions due to the completeness of the solution space. The coefficients of the combination are determined by the boundary conditions. In the numerical example, the stress concentration phenomena produced by the restriction of displacement conditions is discussed in detail.

Development of load-temporal model to predict the further mechanical behaviors of tunnel structure under various boundary conditions

2021 ◽  
Vol 116 ◽  
pp. 104077
Author(s):  
Bowen Du ◽  
Wentao Li ◽  
Xuyan Tan ◽  
Junchen Ye ◽  
Weizhong Chen ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Tunnel Structure ◽  
Mechanical Behaviors ◽  
Various Boundary Conditions ◽  
Temporal Model

Experimental and Theoretical Nonlinear Dynamic Response of Intact and Cracked Bone-Like Specimens With Various Boundary Conditions

2007 ◽  
Vol 129 (5) ◽  
pp. 541-549 ◽  
Author(s):  
Erick Ogam ◽  
Armand Wirgin ◽  
Z. E. A. Fellah ◽  
Yongzhi Xu
Keyword(s):  
Boundary Conditions ◽  
Duffing Oscillator ◽  
Contact Friction ◽  
Nonlinear Dynamic Response ◽  
Various Boundary Conditions ◽  
Vibration Data ◽  
Element Simulation ◽  
Resonance Frequencies ◽  
Vibration Experiment ◽  
Freely Suspended

The potentiality of employing nonlinear vibrations as a method for the detection of osteoporosis in human bones is assessed. We show that if the boundary conditions (BC), relative to the connection of the specimen to its surroundings, are not taken into account, the method is apparently unable to differentiate between defects (whose detection is the purpose of the method) and nonrelevant features (related to the boundary conditions). A simple nonlinear vibration experiment is described which employs piezoelectric transducers (PZT) and two idealized long bones in the form of nominally-identical drinking glasses, one intact, but in friction contact with a support, and the second cracked, but freely-suspended in air. The nonlinear dynamics of these specimens is described by the Duffing oscillator model. The nonlinear parameters recovered from vibration data coupled to the linear phenomena of mode splitting and shifting of resonance frequencies, show that, despite the similar soft spring behavior of the two dynamic systems, a crack is distinguishable from a contact friction BC. The frequency response of the intact glass with contact friction BC is modeled using a direct steady state finite element simulation with contact friction.

Green’s functions for plane problem under various boundary conditions and applications

2003 ◽  
Vol 40 (19) ◽  
pp. 5037-5049 ◽  
Author(s):  
Norio Hasebe ◽  
XianFeng Wang ◽  
Masao Kondo
Keyword(s):  
Boundary Conditions ◽  
Plane Problem ◽  
Green's Functions ◽  
Green’S Functions ◽  
Various Boundary Conditions
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