A numerical illustration of the fusion bonding process

2016 ◽  
Vol 231 (1-2) ◽  
pp. 224-236
Author(s):  
Levent Jusufi ◽  
Roland Körber ◽  
Julia Weimer ◽  
Kristian Lippky ◽  
Stefan Kreling ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Process Parameters ◽  
Bonding Strength ◽  
Material Model ◽  
Bonding Process ◽  
Numerical Illustration ◽  
Fusion Bonding ◽  
Hybrid Joint ◽  
Rate Dependent ◽  
Complex Procedure

Fusion bonding is an innovative joining technology which enables connecting load-adapted material combinations, such as metals with thermoplastic polymers or fibre-reinforced polymers. The bonding process is facilitated by inductively or conductively heating the metallic joining partner and pressing it onto the plastic joining partner. Due to heat conduction, the plastic melts and wets the metallic joining partner, so that after a holding and cooling phase a bonding results without applying additional joining technologies. The connection quality and bonding strength are linked to the selected process parameters and to achieve the desired outcome, it is crucial to choose the appropriate bonding process parameters. The experimental determination of such is an intricate and complex procedure in terms of costs and time efficiency, and hence simulations have become the preferred method for the dimensioning of joints. This paper discusses the numerical illustration of the fusion bonding process between a metal and a pure plastic hybrid joint. The temperature distribution in the joining partners is a significant process parameter that affects the connection quality and bonding strength. Simulations already exist that can predict such temperature distributions.4,5 This paper builds upon a fully coupled thermal-stress analysis of the fusion bonding process and examines a possible numerical illustration of temperature distribution and mechanical displacements to make predictions about the geometric quality of the joints. For this purpose, the paper sets out to characterize the material behaviour of the polymer and hence generates material core values for the implemented material model in the simulation. The primary focus in this paper is on the temperature and shear rate-dependent viscoelastic behaviour of the plastic throughout the entire joining process temperature range. For the validation of the simulation, a real experiment has been carried out under ideal conditions.

scholarly journals Single Process Production of 3D Nonwoven Shell Structures: Part 2 — CFD Modeling of Thermal Bonding Process

2001 ◽  
Vol os-10 (1) ◽  
pp. 1558925001os-10
Author(s):  
R.H. Gong ◽  
Z. Dong ◽  
I. Porat
Keyword(s):  
Temperature Distribution ◽  
Process Parameters ◽  
3D Structure ◽  
Bonding Process ◽  
Shell Structures ◽  
Cfd Modeling ◽  
Thermal Bonding ◽  
Hot Air ◽  
Single Process ◽  
Laboratory Prototype

The design and modeling of a thermal bonding process for the consolidation of 3D nonwoven shell structures is described. The process is modeled using CFD technology to optimize the temperature, velocity and pressure distribution of the hot air flow around the 3D structure. The relationships between the temperature distribution and various process parameters are investigated. The modeling results are experimentally evaluated on a laboratory prototype.

Optimization of Diffusion Bonding Process Parameters of Aluminium AA6061-Fly Ash Composites using Taguchi Method

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
A. Sittaramane ◽  
G. Mahendran
Keyword(s):  
Fly Ash ◽  
Taguchi Method ◽  
Process Parameters ◽  
Diffusion Bonding ◽  
Bonding Strength ◽  
Bonding Temperature ◽  
Bonding Process ◽  
Bonding Pressure ◽  
Bonding Parameters ◽  
Response Table

This paper focused to determine optimal bonding parameters based on Taguchi method for maximizing bonding strength. The experiments were conducted on diffusion bonding machine using aluminium fly ash (AFA) composites. Three bonding parameters such as temperature, pressure and time, each at three levels were examined. Taguchi L27 orthogonal array was used as a design of experiment. The response table and the analysis of variance (ANOVA) were calculated to determine which process parameters significantly affect the bonding strength and also the % contribution of each parameter. The results show that the combination of factors and their levels of A2B3C3 i.e. the bonding done at a temperature of 475°C with a pressure of 10 MPa and time for 20 minutes yielded the optimum i.e. maximum bonding strength. Finally, ANOVA results indicated that all three process parameters significantly affected the bonding strength with a maximum contribution from the bonding temperature (85.93%), followed by bonding time (12.6%) and bonding pressure (1.48%). It is also observed that the bonding strength of the diffusion bonding process can be improved effectively through this approach.

Gold Ball Wire Bonding Energy Transfer Mechanism and Experimental Studies

2014 ◽  
Vol 565 ◽  
pp. 20-24
Author(s):  
Qian Qian Wu ◽  
Li Guo Chen ◽  
Ming Qiang Pan ◽  
Lin Sen Chen
Keyword(s):  
Energy Transfer ◽  
Process Parameters ◽  
Bond Energy ◽  
Bonding Strength ◽  
Experimental Studies ◽  
Bonding Process ◽  
Transfer Model ◽  
Energy Transfer Mechanism ◽  
Gold Ball ◽  
Energy Transfer Model

Because of the complexity of bonding process, the mechanism of bonding has been unable to agree. Accoding to previous research, a new bond energy transfer model is established: bond energy equals to energy caused by temperature rising and the friction energy.Then do experiment on bonding time, bonding stress and ultrasonic energy.Experimental results show that as the increase of process parameters, the bonding strength first increases then decrease, which consistent with the hypothesis.

Modeling of Tread Block Contact Mechanics Using Linear Viscoelastic Theory3

2008 ◽  
Vol 36 (3) ◽  
pp. 211-226 ◽  
Author(s):  
F. Liu ◽  
M. P. F. Sutcliffe ◽  
W. R. Graham
Keyword(s):  
High Speed ◽  
Slip Rate ◽  
Material Model ◽  
Contact Forces ◽  
Block Modeling ◽  
Rate Dependent ◽  
Linear Viscoelastic Material ◽  
Linear Viscoelastic ◽  
The Impact ◽  
Good Agreement

Abstract In an effort to understand the dynamic hub forces on road vehicles, an advanced free-rolling tire-model is being developed in which the tread blocks and tire belt are modeled separately. This paper presents the interim results for the tread block modeling. The finite element code ABAQUS/Explicit is used to predict the contact forces on the tread blocks based on a linear viscoelastic material model. Special attention is paid to investigating the forces on the tread blocks during the impact and release motions. A pressure and slip-rate-dependent frictional law is applied in the analysis. A simplified numerical model is also proposed where the tread blocks are discretized into linear viscoelastic spring elements. The results from both models are validated via experiments in a high-speed rolling test rig and found to be in good agreement.

Lifetime Prediction of Tires with Regard to Oxidative Aging5

2008 ◽  
Vol 36 (1) ◽  
pp. 63-79 ◽  
Author(s):  
L. Nasdala ◽  
Y. Wei ◽  
H. Rothert ◽  
M. Kaliske
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Distribution ◽  
Superposition Principle ◽  
Accelerated Aging ◽  
Material Model ◽  
Aging Behavior ◽  
Element Analysis ◽  
Material Parameters ◽  
Reaction Processes

Abstract It is a challenging task in the design of automobile tires to predict lifetime and performance on the basis of numerical simulations. Several factors have to be taken into account to correctly estimate the aging behavior. This paper focuses on oxygen reaction processes which, apart from mechanical and thermal aspects, effect the tire durability. The material parameters needed to describe the temperature-dependent oxygen diffusion and reaction processes are derived by means of the time–temperature–superposition principle from modulus profiling tests. These experiments are designed to examine the diffusion-limited oxidation (DLO) effect which occurs when accelerated aging tests are performed. For the cord-reinforced rubber composites, homogenization techniques are adopted to obtain effective material parameters (diffusivities and reaction constants). The selection and arrangement of rubber components influence the temperature distribution and the oxygen penetration depth which impact tire durability. The goal of this paper is to establish a finite element analysis based criterion to predict lifetime with respect to oxidative aging. The finite element analysis is carried out in three stages. First the heat generation rate distribution is calculated using a viscoelastic material model. Then the temperature distribution can be determined. In the third step we evaluate the oxygen distribution or rather the oxygen consumption rate, which is a measure for the tire lifetime. Thus, the aging behavior of different kinds of tires can be compared. Numerical examples show how diffusivities, reaction coefficients, and temperature influence the durability of different tire parts. It is found that due to the DLO effect, some interior parts may age slower even if the temperature is increased.

scholarly journals Identification of the LLDPE Constitutive Material Model for Energy Absorption in Impact Applications

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1537
Author(s):  
Luděk Hynčík ◽  
Petra Kochová ◽  
Jan Špička ◽  
Tomasz Bońkowski ◽  
Robert Cimrman ◽  
...  
Keyword(s):  
Strain Rate ◽  
Material Model ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Stress Strain ◽  
Rate Dependent ◽  
Constitutive Material Model ◽  
Principal Directions ◽  
Constitutive Material

Current industrial trends bring new challenges in energy absorbing systems. Polymer materials as the traditional packaging materials seem to be promising due to their low weight, structure, and production price. Based on the review, the linear low-density polyethylene (LLDPE) material was identified as the most promising material for absorbing impact energy. The current paper addresses the identification of the material parameters and the development of a constitutive material model to be used in future designs by virtual prototyping. The paper deals with the experimental measurement of the stress-strain relations of linear low-density polyethylene under static and dynamic loading. The quasi-static measurement was realized in two perpendicular principal directions and was supplemented by a test measurement in the 45° direction, i.e., exactly between the principal directions. The quasi-static stress-strain curves were analyzed as an initial step for dynamic strain rate-dependent material behavior. The dynamic response was tested in a drop tower using a spherical impactor hitting a flat material multi-layered specimen at two different energy levels. The strain rate-dependent material model was identified by optimizing the static material response obtained in the dynamic experiments. The material model was validated by the virtual reconstruction of the experiments and by comparing the numerical results to the experimental ones.

scholarly journals A Material Model for the Orthotropic and Viscous Behavior of Separators in Lithium-Ion Batteries under High Mechanical Loads

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4585
Author(s):  
Marian Bulla ◽  
Stefan Kolling ◽  
Elham Sahraei
Keyword(s):  
Mechanical Behavior ◽  
Lithium Ion ◽  
Material Model ◽  
Tensile Tests ◽  
Element Analysis ◽  
Rate Dependent ◽  
Novel Material ◽  
Li Ion ◽  
Role Based ◽  
Drive Systems

The present study is focused on the development of a material model where the orthotropic-visco-elastic and orthotropic-visco-plastic mechanical behavior of a polymeric material is considered. The increasing need to reduce the climate-damaging exhaust gases in the automotive industry leads to an increasing usage of electric powered drive systems using Lithium-ion (Li-ion) batteries. For the safety and crashworthiness investigations, a deeper understanding of the mechanical behavior under high and dynamic loads is needed. In order to prevent internal short circuits and thermal runaways within a Li-ion battery, the separator plays a crucial role. Based on results of material tests, a novel material model for finite element analysis (FEA) is developed using the explicit solver Altair Radioss. Based on this model, the visco-elastic-orthotropic, as well as the visco-plastic-orthotropic, behavior until failure can be modeled. Finally, a FE simulation model of the separator material is performed, using the results of different tensile tests conducted at three different velocities, 0.1 mm·s−1, 1.0 mm·s−1 and 10.0 mm·s−1 and different orientations of the specimen. The purpose is to predict the anisotropic, rate-dependent stiffness behavior of separator materials in order to improve FE simulations of the mechanical behavior of batteries and therefore reduce the development time of electrically powered vehicles and consumer goods. The present novel material model in combination with a well-suited failure criterion, which considers the different states of stress and anisotropic-visco-dependent failure limits, can be applied for crashworthiness FE analysis. The model succeeded in predicting anisotropic, visco-elastic orthotropic and visco-plastic orthotropic stiffness behavior up to failure.

Computational Modeling of Combat Helmet Performance Analysis Integrating Blunt and Blast Loadings

2020 ◽  
Author(s):  
X. Gary Tan ◽  
Amit Bagchi
Keyword(s):  
System Analysis ◽  
Plastic Material ◽  
Human Head ◽  
Material Model ◽  
Head Model ◽  
Ballistic Impacts ◽  
Rate Dependent ◽  
Brain Responses ◽  
Suspension Geometry ◽  
System Configurations

Abstract Combat helmets have gone through many changes, from shells made of metal to advanced composites using Kevlar and Dyneema, along with introduction of pad suspensions to provide comfort and protection. Helmets have been designed to perform against ballistic and blunt impact threats. But, in today’s warfare, combat helmets are expected to protect against all three threats, blunt, ballistic impacts and blast effects to minimize traumatic brain injury (TBI) and provide a better thermal comfort. We are developing a helmet system analysis methodology integrating the effect of multiple threats, i.e., blast and blunt impacts, to achieve an optimal helmet system design, by utilizing multi-physics computational tools. We used a validated human head model to represent the warfighter’s head. The helmet composite shell was represented by an orthotropic elasto-plastic material model. A strain rate dependent model was employed for pad suspension material. Available dynamic loading data was used to calibrate the material parameters. Multiple helmet system configurations subjected to blast and blunt loadings were considered to quantify their influence on brain biomechanical response. Parametric studies were carried out to assess energy absorption for different suspension geometry and material morphology for different loadings. The resulting brain responses were used with published injury criteria to characterize the helmet system performance through a single metric for each threat type. Approaches to combine single-threat metrics to allow aggregating performance against multiple threats were discussed.

Experimental and Numerical Characterisation of the Cyclic Thermo-Mechanical Behaviour of a High Temperature Forming Tool Alloy

2009 ◽  
Author(s):  
Aditya Deshpande ◽  
Sean B. Leen ◽  
Thomas H. Hyde
Keyword(s):  
High Temperature ◽  
Life Prediction ◽  
Creep Behaviour ◽  
Material Constant ◽  
Superplastic Forming ◽  
Material Model ◽  
Future Application ◽  
Temperature Dependent ◽  
Rate Dependent ◽  
Nickel Chromium

This paper describes high temperature cyclic and creep relaxation testing and modelling of a high nickel-chromium material (XN40F) for application to the life prediction of superplastic forming (SPF) tools. An experimental test programme to characterise the high temperature cyclic elastic-plastic-creep behaviour of the material over a range of temperatures between 20°C and 900°C is described. The objective of the material testing is the development of a high temperature material model for cyclic analyses and life prediction of superplastic forming (SPF) dies for SPF of titanium aerospace components. A two-layer visco-plasticity model which combines both creep and combined isotropic-kinematic plasticity is chosen to represent the material behaviour. The process of material constant identification for this model is presented and the predicted results are compared with the rate-dependent (isothermal) experimental results. The temperature-dependent material model is furthermore applied to simulative thermo-mechanical fatigue (TMF) tests, designed to represent the temperature and stress-strain cycling associated with the most damaging phase of the die cycle. The model is shown to give good correlation with the test data, thus vindicating future application of the material model in thermo-mechanical analyses of SPF dies, for distortion and life prediction.

Influence of strain rate, temperature and fatigue on the radial compression behaviour of Norway spruce

Holzforschung ◽  
2017 ◽  
Vol 71 (6) ◽  
pp. 505-514 ◽  
Author(s):  
Carolina Moilanen ◽  
Tomas Björkqvist ◽  
Markus Ovaska ◽  
Juha Koivisto ◽  
Amandine Miksic ◽  
...  
Keyword(s):  
Strain Rate ◽  
Linear Model ◽  
Norway Spruce ◽  
Material Model ◽  
Radial Compression ◽  
Compression Tests ◽  
Static Compression ◽  
Rate Dependent ◽  
Compression Model ◽  
Wood Compression

Abstract A dynamic elastoplastic compression model of Norway spruce for virtual computer optimization of mechanical pulping processes was developed. The empirical wood behaviour was fitted to a Voigt-Kelvin material model, which is based on quasi static compression and high strain rate compression tests (QSCT and HSRT, respectively) of wood at room temperature and at high temperature (80–100°C). The effect of wood fatigue was also included in the model. Wood compression stress-strain curves have an initial linear elastic region, a plateau region and a densification region. The latter was not reached in the HSRT. Earlywood (EW) and latewood (LW) contributions were considered separately. In the radial direction, the wood structure is layered and can well be modelled by serially loaded layers. The EW model was a two part linear model and the LW was modelled by a linear model, both with a strain rate dependent term. The model corresponds well to the measured values and this is the first compression model for EW and LW that is based on experiments under conditions close to those used in mechanical pulping.

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