FSI and non-FSI studies on a functionally graded temperature-responsive hydrogel bilayer in a micro-channel

2021 ◽  
Author(s):  
Hashem Mazaheri ◽  
Amin Khodabandehloo
Keyword(s):  
Fluid Flow ◽  
Fem Analysis ◽  
Functionally Graded ◽  
Cross Linking ◽  
Micro Channel ◽  
Thickness Direction ◽  
Structure Interaction ◽  
Temperature Responsive ◽  
The Right ◽  
Hydrogel Bilayer

Abstract Taking into account both fluid-structure interaction (FSI) and non-FSI simulations, the deformation of a bilayer is investigated in this paper. The bilayer, which is utilized in a micro-channel, consists of a Functionally-graded (FG) temperature-responsive hydrogel layer and an incompressible elastomeric one. Allocating two different positions to the elastomeric layer, we make two different bilayers where in one of them, the elastomer layer is located on the left (LSE) and on the right (RSE) in another one. Also, to see the effect of grading, two bilayers with homogenous hydrogel layers with different amounts of cross-linking density are considered. For FG cases in which the hydrogel layer's properties vary through thickness direction, both ascending and descending arrangements are analyzed. Each simulation, whether it is FSI or non-FSI, is conducted utilizing three software. FLUENT for fluid domain examinations, ABAQUS for FEM analysis, and MpCCI to couple two aforementioned simulation domains. By extracting and comparing both simulations results, it is observed that the influence of the fluid flow is very significant and should not be ignored. Moreover, it is discovered that the fluid flow affects more the RSE configuration and also the bilayers with lower amounts of cross-linking density. Finally, we investigate how some parameters, such as inlet pressure, can affect the behavior of the bilayer.

Study of Fluid–Structure Interaction in a Functionally Graded pH-Sensitive Hydrogel Micro-Valve

2020 ◽  
Vol 12 (05) ◽  
pp. 2050057 ◽  
Author(s):  
Hashem Mazaheri ◽  
Amir Ghasemkhani ◽  
Soroush Sabbaghi
Keyword(s):  
Fluid Structure Interaction ◽  
Fem Analysis ◽  
Ph Sensitive ◽  
Functionally Graded ◽  
Third Party ◽  
Smart Devices ◽  
Cross Linking ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Significant Difference

In this work, fluid–structure interaction (FSI) simulations, as well as non-FSI ones, are conducted to study the behavior of a functionally graded (FG) pH-sensitive micro-valve. The FEM analysis of the hydrogel is performed in ABAQUS while the fluid domain is analyzed in ANSYS fluent. To investigate the FSI and FG effects, both FSI and non-FSI simulations are performed for pH-sensitive micro-valve with homogeneous cross-linking distribution beside the FG cases. Two simulation domains are coupled by using a third-party software named MpCCI for both FSI and non-FSI simulations. For the FG hydrogel, linear and exponential property distributions are considered. The obtained results show a significant difference between the FG and homogeneous hydrogel behavior for both simulation methods. Additionally, the results emphasize that FSI consideration has a crucial role in the design of these smart devices. Especially, remarkable difference is observed for the closing pH of the micro-valve as well as the flow-rate diagrams. For example, a leakage is observed in FSI simulations for the closing pH of the non-FSI simulations that indicates the importance of the FSI effect. Finally, the effect of the cross-linking density distribution and the inlet pressure of micro-valve are studied and the results are analyzed.

Fluid-structure interaction simulations for a temperature-sensitive functionally graded hydrogel-based micro-channel

2020 ◽  
pp. 1045389X2096317
Author(s):  
Amir Ghasemkhani ◽  
Hashem Mazaheri ◽  
Arya Amiri
Keyword(s):  
Fluid Structure Interaction ◽  
Vital Role ◽  
Functionally Graded ◽  
Temperature Sensitive ◽  
Micro Channel ◽  
Exponential Form ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Number Of Layers ◽  
The Difference

The behavior of a temperature-sensitive micro-channel have been investigated in this study which mainly includes a functionally graded (FG) hydrogel as a sensor or an actuator. In order to achieve this goal, both fluid-structure interaction (FSI) and non-FSI simulations are conducted for hydrogel with homogeneous property distribution as well as FG hydrogels with different number of layers (2–16 layers). Moreover, this study investigates the FG hydrogel cross-linking density that obeys a general exponential form. In addition to all mentioned, the FG hydrogels are considered in both ascending and descending states with vertically and horizontally functionally graded property distributions (VFG and HFG hydrogels). Subsequently, the importance of the difference between the FG and homogenous hydrogels has been highlighted in the findings of the study. Besides, the FSI influence has a vital role in these structures especially once an FG material is utilized. According to the findings, the ascending and descending distributions of the hydrogel properties may significantly affect the micro-channel behavior, especially in horizontally graded type. This process can be done in a way that for descending distribution of HFG there exist no closing state for the micro-channel.

scholarly journals Numerical Analysis of the Bond Strength between Two Methacrylic Polymers by Surface Modification

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3927
Author(s):  
Joanna Taczała ◽  
Katarzyna Rak ◽  
Jacek Sawicki ◽  
Michał Krasowski
Keyword(s):  
Numerical Analysis ◽  
Bond Strength ◽  
Angular Position ◽  
Fem Analysis ◽  
Groove Depth ◽  
Chemical Reagent ◽  
Shear Process ◽  
3D Geometry ◽  
The Right ◽  
Artificial Teeth

The creation of acrylic dentures involves many stages. One of them is to prepare the surfaces of artificial teeth for connection with the denture plates. The teeth could be rubbed with a chemical reagent, the surface could be developed, or retention hooks could be created. Preparation of the surface is used to improve the bond between the teeth and the plate. Choosing the right combination affects the length of denture use. This work focuses on a numerical analysis of grooving. The purpose of this article is to select the shape and size of the grooves that would most affect the quality of the bond strength. Two types of grooves in different dimensional configurations were analyzed. The variables were groove depth and width, and the distance between the grooves. Finally, 24 configurations were obtained. Models were analyzed in terms of their angular position to the loading force. Finite element method (FEM) analysis was performed on the 3D geometry created, which consisted of two polymer bodies under the shear process. The smallest values of the stresses and strains were characterized by a sample with parallel grooves with the grooving dimensions width 0.20 mm, thickness 0.10 mm, and distance between the grooves 5.00 mm, placed at an angle of 90°. The best dimensions from the parallel (III) and cross (#) grooves were compared experimentally. Specimens with grooving III were not damaged in the shear test. The research shows that the shape of the groove affects the distribution of stresses and strains. Combining the selected method with an adequately selected chemical reagent can significantly increase the strength of the connection.

Fluid–Structure Interaction of High Aspect-Ratio Hair-Like Micro-Structures Through Dimensional Transformation Using Lattice Boltzmann Method

2016 ◽  
Vol 08 (08) ◽  
pp. 1650095 ◽  
Author(s):  
H. Devaraj ◽  
Kean C. Aw ◽  
E. Haemmerle ◽  
R. Sharma
Keyword(s):  
Fluid Flow ◽  
Drag Force ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Momentum Exchange ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Micro Structures

3D printed hair-like micro-structures have been previously demonstrated in a novel micro-fluidic flow sensor aimed at sensing air flows down to rates of a few milliliters per second. However, there is a lack of in-depth understanding of the structural response of these ‘micro-hairs' under a fluid flow field. This paper demonstrates the use of lattice Boltzmann methods (LBM) to understand this structural response towards a better optimization of the micro-hair flow sensors designed to suit the end applications' needs. The LBM approach was chosen as an efficient alternative to simulate Navier–Stokes equations for modeling fluid flow around complex geometries primarily for improved accuracy and simplicity with lesser computational costs. As the spatial dimensions of the sensor's flow channel are much larger in comparison to the actual micro-hairs (the sensing element), a multidimensional approach of combining two-dimensional (D2Q9) and three-dimensional (D3Q19) lattice configurations were implemented for improved computational speeds and efficiency. The drag force on the micro-hairs was estimated using the momentum-exchange method in the D3Q19 configuration and this drag force is transferred to the structural analysis model which determines the micro-hair deformation using Euler–Bernoulli beam theory. The entirety of the LBM Fluid–Structure Interaction (FSI) model was implemented within MATLAB and the obtained results are compared against the numerical model implemented on a commercially available software package.

Free Vibration and Thermal Fluid Structure Interaction Simulation of Functionally Graded Pipe by Modeling As Layered Structure

2020 ◽  
Author(s):  
Ziyi Su ◽  
Kazuaki Inaba ◽  
Amit Karmakar ◽  
Apurba Das
Keyword(s):  
Free Vibration ◽  
Layered Structure ◽  
Volume Fraction ◽  
Fluid Structure Interaction ◽  
Functionally Graded ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Layered Model ◽  
Piping Systems ◽  
Complex Phenomena

Abstract Functionally graded materials (FGMs) are advanced class of composite materials which can be used as the thermal barrier to protect inner components from the outside high temperature environment. In FGMs, the volume fraction of each constituent can be tailored made across the thickness for desired applications. In this work, the simulation of FGMs in pipes is considered. Despite the wide application of pipes in machinery, those pipes would suffer from many safety problems, such as thermal stress, cavitation, fracture etc. Application of FGMs to the piping systems could lead to some new solutions accounting for safety measures and higher service life. However, the complex phenomena within the fluid structure interaction are hard to describe with the theoretical solution. The visualization of results from simulation will be helpful in understanding the distribution of kinds of physical quantities within the concerned model. For the simulation, FGMs are modeled as the layered structure in the standard finite element method (FEM) package based on FGM constituent law. The free vibration of the FG pipe is simulated and the accuracy of layered model is verified by numerical calculations. Further, based on the layered model, conjugate heat transfer simulations in a heat exchanger with FGMs are conducted.

Fluid-Structure Interaction Approach for Numerical Investigation of a Flexible Hydrofoil Deformations in Turbulent Fluid Flow

2018 ◽  
Author(s):  
M. Benaouicha ◽  
S. Guillou ◽  
A. Santa Cruz ◽  
H. Trigui
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Time Step ◽  
Fluid Structure ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Structure Interaction ◽  
Ale Formulation

The study deals with a 3D Fluid-Structure Interaction (FSI) numerical model of a rectangular cantilevered flexible hydrofoil subjected to a turbulent fluid flow regime. The structural response and dynamic deformations are studied by analyzing the oscillations frequencies and amplitudes, under a hydrodynamics loads. The obtained numerical results are confronted with experimental ones, for validation. The numerical model is performed in the same geometric, physical and material conditions as the experimental set-up carried out in a hydrodynamic tunnel. A polyacetal (POM) flexible hydrofoil NACA0015 with an angle of attack of 8° is considered to be immersed in a fluid flow at a Reynold number of 3 × 105. The structure is initially at rest and then moved by the action of the fluid flow. The numerical model is based on a strong coupling procedure for solving the Fluid-Structure Interaction problem. The Arbitrary Lagrangian-Eulerian (ALE) formulation of the Navier-Stokes equations is used and an anisotropic diffusion equation is solved to compute the fluid mesh velocity and position at each time step. The finite volume method is used for the numerical resolution of the fluid dynamics equations. The structure deformations are described by the linear elasticity equation which is solved by the finite elements method. The Fluid-Structure coupled problem is solved by using the partitioned FSI implicit algorithm. A good agreement between numerical and experimental results for the hydrodynamics coefficients and hydrofoil deformations, maximum deflection and frequencies is obtained. The added mass and damping are analyzed and then the FSI effect on the dynamic deformations of the structure is highlighted.

Love Wave in an Isotropic Half-Space with a Graded Layer

2013 ◽  
Vol 325-326 ◽  
pp. 252-255
Author(s):  
Li Gang Zhang ◽  
Hong Zhu ◽  
Hong Biao Xie ◽  
Jian Wang
Keyword(s):  
Shear Modulus ◽  
Half Space ◽  
Analytical Solutions ◽  
Love Wave ◽  
Elastic Half Space ◽  
Functionally Graded ◽  
Thickness Direction ◽  
Vibration Model ◽  
General Dispersion ◽  
Functionally Graded Layer

This work addresses the dispersion of Love wave in an isotropic homogeneous elastic half-space covered with a functionally graded layer. First, the general dispersion equations are given. Then, the approximation analytical solutions of displacement, stress and the general dispersion relations of Love wave in both media are derived by the WKBJ approximation method. The solutions are checked against numerical calculations taking an example of functionally graded layer with exponentially varying shear modulus and density along the thickness direction. The dispersion curves obtained show that a cut-off frequency arises in the lowest order vibration model.

scholarly journals Study on the Effect of Heat-Input on the Thickness of the Heat-Affected Zone of the SUS316L Steel Welded Joint by Numerical Simulation

2021 ◽  
Vol 31 (5) ◽  
pp. 68-74
Keyword(s):  
Numerical Simulation ◽  
Heat Affected Zone ◽  
Heat Input ◽  
Welded Joint ◽  
Plate Thickness ◽  
Great Influence ◽  
Thickness Direction ◽  
Welding Joint ◽  
Simulation Results ◽  
The Right

The thickness of the heat-affected zone (HAZ) has a great influence on the strength of the welded joint, so one of the important tasks is to control the HAZ to a small enough level, through using the suitable heat-input (qd). In this study, the authors use SYSWELD software to compute and build a relationship between the heat-input and the thickness of the heat-affected zone in the plate thickness direction to find the right heat-input for researched welding joint. The simulation results show that when welding the root pass with qd > 552 J/mm and the cap pass with 754 J/mm < qd < 1066 J/mm, the thickness of HAZ were increased with a function almost linearly.

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