Numerical simulation of thermal properties at Cu/Al interfaces based on hybrid model

2015 ◽  
Vol 32 (3) ◽  
pp. 574-584
Author(s):  
Yunqing Tang ◽  
Liqiang Zhang ◽  
Haiying Yang ◽  
Juan Guo ◽  
Ningbo Liao ◽  
...  

Purpose – The purpose of this paper is to investigate thermal properties at Cu/Al interfaces. Design/methodology/approach – A hybrid (molecular dynamics-interface stress element-finite element model (MD-ISE-FE) model is constructed to describe thermal behaviors at Cu/Al interfaces. The heat transfer simulation is performed after the non-ideal Cu/Al interface is constructed by diffusion bonding. Findings – The simulation shows that the interfacial thermal resistance is decreasing with the increase of bonding temperature; while the interfacial region thickness and interfacial thermal conductivity are increasing with similar trends when the bonding temperature is increasing. It indicates that the higher bonding temperature can improve thermal properties of the interface structure. Originality/value – The MD-ISE-FE model proposed in this paper is computationally efficient for interfacial heat transfer problems, and could be used in investigations of other interfacial behaviors of dissimilar materials. All these are helpful for the understanding of thermal properties of wire bonding interface structures. It implies that the MD-ISE-FE multiscale modeling approach would be a potential method for design and analysis of interfacial characteristics in micro/nano assembly.

2014 ◽  
Vol 24 (7) ◽  
pp. 1553-1569 ◽  
Author(s):  
H.G. Rábade ◽  
P. Vellando ◽  
F. Padilla ◽  
R. Juncosa

Purpose – A new coupled finite element model has been developed for the joint resolution of both the shallow water equations, that governs the free surface flow, and the groundwater flow equation that governs the motion of water through a porous media. The paper aims to discuss these issues. Design/methodology/approach – The model is based upon two different modules (surface and ground water) previously developed by the authors, that have been validated separately. Findings – The newly developed software allows for the assessment of the fluid flow in natural watersheds taking into account both the surface and the underground flow in the way it really takes place in nature. Originality/value – The main achievement of this work has dealt with the coupling of both models, allowing for a proper moving interface treatment that simulates the actual interaction that takes place between surface and groundwater in natural watersheds.


2020 ◽  
Vol 72 (5) ◽  
pp. 687-693
Author(s):  
Liuqing Yang ◽  
Ming Hu ◽  
Deming Zhao ◽  
Jing Yang ◽  
Xun Zhou

Purpose The purpose of this paper is to develop a novel method for analyzing wheel-rail (W-R) contact using thermo-mechanical measurements and study the effects of heating on the characteristics of W-R contact under different creepages. Design/methodology/approach This study developed an implicit-explicit finite element (FE) model which could solve both partial slip and full sliding problems by setting different angular velocities on the wheels. Based on the model, four material types under six different creepages were simulated. Findings The results showed that frictional heating significantly affected the residual stress distribution under large creepage conditions. As creepage increased, the temperature of the wheel tread and rail head rose and the peak value was located at the trailing edge of the contact patch. Originality/value The proposed FE model could reduce computational time and thus cost to about one-third of the amount commonly found in previous literature. Compared to other studies, these results are in good agreement and offer a reasonable alternative method for analyzing W-R contact under various conditions. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0298


2020 ◽  
Vol 26 (9) ◽  
pp. 1627-1635
Author(s):  
Dongqing Yang ◽  
Jun Xiong ◽  
Rong Li

Purpose This paper aims to fabricate inclined thin-walled components using positional wire and arc additive manufacturing (WAAM) and investigate the heat transfer characteristics of inclined thin-walled parts via finite element analysis method. Design/methodology/approach An inclined thin-walled part is fabricated in gas metal arc (GMA)-based additive manufacturing using a positional deposition approach in which the torch is set to be inclined with respect to the substrate surface. A three-dimensional finite element model is established to simulate the thermal process of the inclined component based on a general Goldak double ellipsoidal heat source and a combined heat dissipation model. Verification tests are performed based on thermal cycles of locations on the substrate and the molten pool size. Findings The simulated results are in agreement with experimental tests. It is shown that the dwell time between two adjacent layers greatly influences the number of the re-melting layers. The temperature distribution on both sides of the substrate is asymmetric, and the temperature peaks and temperature gradients of points in the same distance from the first deposition layer are different. Along the deposition path, the temperature distribution of the previous layer has a significant influence on the heat dissipation condition of the next layer. Originality/value The established finite element model is helpful to simulate and understand the heat transfer process of geometrical thin-walled components in WAAM.


2020 ◽  
Vol 17 (6) ◽  
pp. 761-784
Author(s):  
Ali Belhocine ◽  
Oday Ibraheem Abdullah

Purpose This study aims to investigate numerically a thermomechanical behavior of disc brake using ANSYS 11.0 which applies the finite element method (FEM) to solve the transient thermal analysis and the static structural sequentially with the coupled method. Computational fluid dynamics analysis will help the authors in the calculation of the values of the heat transfer (h) that will be exploited in the transient evolution of the brake disc temperatures. Finally, the model resolution allows the authors to visualize other important results of this research such as the deformations and the Von Mises stress on the disc, as well as the contact pressure of the brake pads. Design/methodology/approach A transient finite element analysis (FEA) model was developed to calculate the temperature distribution of the brake rotor with respect to time. A steady-state CFD model was created to obtain convective heat transfer coefficients (HTC) that were used in the FE model. Because HTCs are dependent on temperature, it was necessary to couple the CFD and FEA solutions. A comparison was made between the temperature of full and ventilated brake disc showing the importance of cooling mode in the design of automobile discs. Findings These results are quite in good agreement with those found in reality in the brake discs in service and those that may be encountered before in literature research investigations of which these will be very useful for engineers and in the design field in the vehicle brake system industry. These are then compared to experimental results obtained from literatures that measured ventilated discs surface temperatures to validate the accuracy of the results from this simulation model. Originality/value The novelty of the work is the application of the FEM to solve the thermomechanical problem in which the results of this analysis are in accordance with the realized and in the current life of the braking phenomenon and in the brake discs in service thus with the thermal gradients and the phenomena of damage observed on used discs brake.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Cletus Matthew Magoda ◽  
Jasson Gryzagoridis ◽  
Kant Kanyarusoke

Purpose The purpose of this paper is to validate an assumption of what to use as an effective (steady state) heat transfer coefficient of thermal conductivity for the honeycomb core sandwiched by Fiberglass face sheets composite. A one-dimensional model based on Fourier law is developed. The results are validated experimentally. Design/methodology/approach The results were obtained from the one-dimensional mathematical model of an overall or effective heat conductivity of the Honeycomb composite panel. These results were validated experimentally by applying heat flux on the specimen under controlled environment. The surface temperatures at different voltages were recorded and analysed. The skin of the sandwich composite material used in the investigation was Fiberglass sheet with a thickness of 0.5 mm at the bottom and 1.0 mm at the top surface. Both skins have a stacking sequence of zero degrees. Due to the presence of air cells in the core (Honeycomb), the model considers the conduction, convection and radiation heat transfer, across the thickness of the panel, combined as an effective conduction mode, whose value may be predicted by using the coefficient of thermal conductivity of the air based on the average temperature difference between the two skins. The experimental results for the heat transfer through the thickness of the panel provide validation of this assumption/prediction. Both infrared thermography and conventional temperature measurement techniques (thermocouples) were used to collect the data. Findings The heat transfer experiment and mathematical modeling were conducted. The data obtained were analyzed, and it was found that the effective thermal conductivity was temperature-dependent as expected. The effective thermal conductivity of the honeycomb panel was close to that of air, and its value could be predicted if the panel surface temperatures were known. It was also found that as temperature raised the variation between experimental and predicted effective air conduction raised up. This is because there was an increase in molecular diffusion and vibration. Therefore, the convection heat transfer increased at high temperatures and the air became an insulator. Originality/value Honeycomb composite panels have excellent physical and thermal properties that influence their performance. This study provides an appropriate method in determining thermal conductivity, which is one of the critical thermal properties of porous composite material. This paper also gives useful and practical data to industries that use or manufacture honeycomb composite panels.


Author(s):  
Amir Khalilollahi ◽  
Russell L. Warley ◽  
Oladipo Onipede

Boards made of composites are susceptible of structural failure or irreversible damage under thermally raised stresses. A thermal/structural finite element model is integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board is modeled as a thin plate containing four heated flush rectangular areas that represent the electronic modules. The finite element model should be to able to accept the convection heat transfer on the board surface, heat generation in the modules, and directional conduction inside the board. A detailed 3-D CFD model is incorporated to predict the conjugate heat transfer coefficients that strongly affect the temperature distribution in the board and modules. Structural analyses are performed by a FE model that uses the heat transfer coefficients mentioned above, and structural elements capable of handling orthotropic material properties. The stress fields are obtained and studied for the models possessing two and there laminates with different fiber orientations, and inter-fiber angles. Appreciable differences in values of max stress intensity were observed as the fiber orientation and inter-fiber angle changed. The angular parameters in this study were guided by experimental design (DOE) concepts leading to a metamodel of the stress intensity in the board. The optimum design variables found by the equations of the metamodel.


Author(s):  
E. Hachem ◽  
H. Digonnet ◽  
E. Massoni ◽  
T. Coupez

PurposeThe purpose of this paper is to present an immersed volume method that accounts for solid conductive bodies (hat‐shaped disk) in calculation of time‐dependent, three‐dimensional, conjugate heat transfer and fluid flow.Design/methodology/approachThe incompressible Navier‐Stokes equations and the heat transfer equations are discretized using a stabilized finite element method. The interface of the immersed disk is defined and rendered by the zero isovalues of a level set function. This signed distance function allows turning different thermal properties of each component into homogeneous parameters and it is coupled to a direct anisotropic mesh adaptation process enhancing the interface representation. A monolithic approach is used to solve a single set of equations for both fluid and solid with different thermal properties.FindingsIn the proposed immersion technique, only a single grid for both air and solid is considered, thus, only one equation with different thermal properties is solved. The sharp discontinuity of the material properties was captured by an anisotropic refined solid‐fluid interface. The robustness of the method to compute the flow and heat transfer with large materials properties differences is demonstrated using stabilized finite element formulations. Results are assessed by comparing the predictions with the experimental data.Originality/valueThe proposed method demonstrates the capability of the model to simulate an unsteady three‐dimensional heat transfer flow of natural convection, conduction and radiation in a cubic enclosure with the presence of a conduction body. A previous knowledge of the heat transfer coefficients between the disk and the fluid is no longer required. The heat exchange at the interface is solved and dealt with naturally.


2010 ◽  
Vol 27 (5) ◽  
pp. 658-673 ◽  
Author(s):  
M.Q. Al‐Odat

PurposeThe purpose of this paper is to conduct a full three‐dimensional numerical analysis to simulate the thermal behavior of high speed steel (HSS) cutting tool, with temperature dependent thermal properties, in dry machining with embedded heat pipe (HP), and investigate the effects of HP installation, variable thermal properties, generated heat flux and cutting speed.Design/methodology/approachThe heat transfer equation used to predict cutting tool temperature is parabolic partial differential equation. Grid points including independent variables are initially formed in solution of partial differential equation by finite element method (FEM). In this paper, one‐dimensional heat transfer equation with variable thermophysical properties is solved by FEM.FindingsIn this paper, the heat transfer equation in cutting tool is solved for variable thermophysical properties and the temperature field and temperature history are obtained. Variable thermophysical properties are considered to display the temperature fields in the cutting tool.Originality/valueA full three‐dimensional numerical analysis is conducted to simulate the thermal behavior of HSS cutting tool, with temperature dependent thermal properties, in dry machining with embedded HP. The heat conduction equation is solved by FEM analysis.


Author(s):  
Amir Khalilollahi ◽  
Russell L. Warley

Composite printed electronic boards are susceptible of structural failure or irreversible damage under thermally raised stresses. A thermal/structural finite element model is integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board is modeled as a thin plate containing four heated flush rectangular areas that represent the electronic modules. The finite element model should be to able to accept the convection heat transfer on the board surface, heat generation in the modules, and directional conduction inside the board. A detailed 3-D CFD model is incorporated to predict the conjugate heat transfer coefficients that strongly affect the temperature distribution in the board and modules. Structural analyses are performed by a FE model that uses the heat transfer coefficients mentioned above, and structural elements capable of handling orthotropic material properties. The stress fields are obtained and compared for the models possessing different fiber orientations and fiber volume fractions. Appreciable differences in stress and thermal gradient fields were observed. The values of fiber volume fraction and fiber orientation at which to conduct analyses was guided by experimental design (DOE) ideas leading to a metamodel of the stress intensity and temperature gradient in the board which was used to represent the complied results of this study.


2016 ◽  
Vol 1138 ◽  
pp. 113-118
Author(s):  
Monica Iordache ◽  
Eduard Nitu ◽  
Claudiu Badulescu ◽  
Doina Iacomi ◽  
Lia Nicoleta Boţilă ◽  
...  

Friction Stir Welding (FSW) is a solid state joining process realized by the interaction between a non-consumable welding tool that rotates on the contact surfaces of the combined parts. Welding dissimilar materials aluminum and copper by FSW are of great interest because Al and Cu are two most common engineering materials widely used in many industries. This paper presents an investigation concerning the influence of the rotation of the tool on temperatures during the welding process. Also, the welding of copper and aluminum materials by FSW process was simulated using a finite element model. Three-dimensional FE model has been developed in ABAQUS/Explicit using the Coupled Eulerian Lagrangian method, the Johnson–Cook material law and the Coulomb’s Law of friction and was validated by infrared thermography method and thermocouple measurement.


Sign in / Sign up

Export Citation Format

Share Document