The development of a material model for cast iron that can be used for brake system analysis

2002 ◽  
Vol 216 (5) ◽  
pp. 349-362 ◽  
Author(s):  
S Koetniyom ◽  
P C Brooks ◽  
D C Barton
Keyword(s):  
Finite Element ◽  
Cast Iron ◽  
System Analysis ◽  
Preliminary Investigation ◽  
Material Model ◽  
Mechanical Tests ◽  
Brake Disc ◽  
Tension And Compression ◽  
High Plastic Strain ◽  
Iron Material

This paper describes the methodology and reports the results of detailed thermomechanical finite element analyses of cast iron brake discs under repeated high g braking conditions. The thermal analysis allows for heat loss from the vanes in a back-ventilated disc design as well as heat transfer to other parts of the brake assembly. The cast iron material properties required for the non-linear structural analysis are generated by mechanical tests on samples cut from the brake disc. The material model developed by the authors allows for the variation of flow stress with temperature and for the different yield properties of cast iron in tension and compression. The finite element results, derived from a preliminary investigation, indicate regions of high plastic strain accumulation which may lead to disc crazing and/or cracking and enable comparisons to be made between back- and front-vented rotor designs.

Modelling of grey cast iron for application to brake discs for heavy vehicles

2016 ◽  
Vol 231 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Gaël Le Gigan ◽  
Magnus Ekh ◽  
Tore Vernersson ◽  
Roger Lundén
Keyword(s):  
Cast Iron ◽  
Elevated Temperatures ◽  
Kinematic Hardening ◽  
Frictional Heating ◽  
Material Model ◽  
Tensile Tests ◽  
Brake Disc ◽  
Brake Discs ◽  
Different Temperatures ◽  
Tension And Compression

Cast iron brake discs are commonly used in the automotive industry, and efforts are being made to gain a better understanding of the thermal and mechanical phenomena occurring at braking. The high thermomechanical loading at braking arises from interaction between the brake disc and the brake pads. Frictional heating generates elevated temperatures with a non-uniform spatial distribution often in the form of banding or hot spotting. These phenomena contribute to material fatigue and wear and possibly also to cracking. The use of advanced calibrated material models is one important step towards a reliable analysis of the mechanical behaviour and the life of brake discs. In the present study, a material model of the Gurson–Tvergaard–Needleman type is adopted, which accounts for asymmetric yielding in tension and compression, kinematic hardening effects, viscoplastic response and temperature dependence. The material model is calibrated using specimens tested in uniaxial cyclic loading for six different temperatures ranging from room temperature to 650 °C. A special testing protocol is followed which is intended to activate the different features of the material model. Validation of the model is performed by using tensile tests and thermomechanical experiments. An application example is given where a 10° sector of a brake disc is analysed using the commercial finitie element code Abaqus under a uniformly applied heat flux on the two friction surfaces. The results indicate that the friction surface of the hat side and the neck can be critical areas with respect to fatigue for the uniform heating studied.

Evolution of Pipe Properties During Reel-Lay Process: Experimental Characterisation and Finite Element Modelling

2005 ◽  
Author(s):  
Michae¨l Martinez ◽  
George Brown
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Computation Time ◽  
Material Model ◽  
Point Of View ◽  
Fatigue Properties ◽  
Geometrical Shape ◽  
Element Analysis ◽  
New Model ◽  
Tension And Compression

The development of finite element analysis, in terms of simulation power and theoretical model accuracy, enables one to understand and simulate industrial processes more precisely, especially those involving non linear behaviour and analysis. Reeled pipe technology is one of these, and has a lot to gain from this increasing efficiency. In the reel-lay process the pipe is first reeled onto a drum on a vessel for transportation. During offshore installation the pipe is unreeled, straightened and deployed into the sea. During the process, the pipe is fully and cyclically plastified. Plastification modifies the pipe properties, which is not by itself detrimental but should be understood by the designer. Pipe properties are affected in three ways: geometrical shape – reeling and straightening induce some residual ovalisation; mechanical properties – yield stress, hardening slope, isotropy are modified; and fatigue properties. Technip and IFP have studied these property evolutions for many years, both from an experimental and a numerical point of view. The present paper discusses the first two points. A wide experimental programme has been performed. Full scale pipes were reeled and straightened on a bending rig device especially built for that purpose. Pipe ovalisation was monitored through the whole process. Pipe mechanical properties were also fully characterised in the pipe axial, hoop and thickness directions, both in tension and compression, before and after reeling process. Extruded and UOE pipes were tested and characterised. Pipe initial properties are dependent on the manufacturing process but they are modified by the reeling process. Reeling induces some anisotropy that cannot be properly accounted for by usual plasticity models. Finite element simulations with Abaqus software, using the material behaviour of unreeled pipe, underestimate stiffness evolution in the hoop direction and overestimate ovalisation induced by the reeling process. Anisotropy has indeed a great effect on ovalisation that results from an interaction between axial and hoop loading. Hardening is also a key parameter. A new plasticity model has been written in an Abaqus User Material Model, known as UMAT. The new model is based on an anisotropic Hill criterion and special attention is paid to the hardening. This new model reduces by more than two the error on ovality estimation, and gives a realistic prediction of material anisotropy evolution through the process. Although, the tuning of the model coefficients is more complex than for usual models, its use is quite straightforward and does not increase computation time.

scholarly journals Determination of Braking Speed of Developed Hybrid Particle Reinforced Aluminium Alloy

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Justine O Bucham ◽  
Baba A Aliyu ◽  
Abubakar Muhammad
Keyword(s):  
Silicon Carbide ◽  
Cast Iron ◽  
Aluminium Alloy ◽  
Nodular Cast Iron ◽  
Mechanical Tests ◽  
Coconut Shell ◽  
Brake Disc ◽  
Alloy Sample ◽  
Alloy Matrix ◽  
Coconut Shell Ash

Abstract- This paper is aimed at comparing the braking speed of the developed Composite Brake Disc (CBD) with that of a nodular cast iron Honda Accord (2000) Model Brake Disc (HABD). The test samples were produced from Aluminium alloy (Al6061), Coconut Shell Ash (CSA) and Silicon Carbide (SiC) by Stir casting and machined into standard specimens for microstructure analysis, density test, mechanical tests (hardness, tensile and impact), wear test and thermal test. The characterization of coconut shell ash particle was carried out using X-ray Flourescent equipment. Six samples were produced, four composite samples; C1 (70% Al, 5% SiC, 20% CSA), C2 (70% Al, 10% SiC, 15% CSA), C3 (70% Al, 15% SiC, 10% CSA) and C4 (70% Al, 20% SiC, 5% CSA), aluminium alloy sample (A1) and as-cast nodular cast iron sample (N1) obtained from HABD. Sample ‘C4’ had the best physical, mechanical, wear and thermal properties (Densty: 3.15 g/cm3, Hardness: 68 kg/mm2, Tensile Strength:  196.12 N/mm2, Impact Energy: 8.05 J, Wear rate: 0.0002328 g/m, Thermal Conductivity: 72.57 W/m-K) and was used to produce the CBD. From the values of coefficient of frictions obtained for CBD and HABD, the braking speeds were calculated and HABD was seen to have a lower braking speed (56.65 m/s) than the CBD (94.42 m/s) because of its higher coefficient of friction. The higher braking speed of the composite brake disc (CBD) as compared to the Honda Accord Brake Disc (HABD) could be as a result of inadequate reinforcements in the aluminium alloy matrix. Hence,  the produced CBD cannot be used as an alternative for the nodular cast iron Honda accord brake disc (HABD) even as problems of heavy weight and breakage that may occur due to heavy impact associated with cast iron brake disc have been addressed using the developed composite.Keywords,- Aluminium Alloy, Braking Speed, Coconut Shell, Composite, Silicon Carbide

scholarly journals Structural and Thermal Analysis of Brake Drum

2020 ◽  
Vol 6 (12) ◽  
pp. 8-15
Author(s):  
Shaik Chand Mabhu Subhani A.Pavan Kumar and Dr.D Venkata Rao
Keyword(s):  
Thermal Analysis ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Cast Iron ◽  
Thermal Stresses ◽  
Carbon Composite ◽  
Brake Disc ◽  
Element Analysis ◽  
Drum Brake ◽  
Brake Drum

The brake drum is a specialized brake that uses the concept of friction to decelerate or to stop the vehicle. The deceleration is achieved by the assistance of the friction generated by a set of brake shoes or pads. During the brake operation heat is ejected out this causes damage to the brake. Disc (Rotor) brakes are exposed to large thermal stresses during routine braking and extraordinary thermal stresses during hard braking. To satisfy this condition the drum material should possess a high thermal conductivity, thermal capacity and high strength .The common material used for construction of brake drum is cast iron. The aim of the project is to design, model a disc. Modeling is done using catia. Structural and Thermal analysis is to be done on the drum brakes using four materials Stainless Steel, gray Cast iron, carbon carbon composite & aluminum metal matrix. The shoes of this kind of brake are contained within the drum and expand outwards when the brake is applied. Such kind of brakes is used in medium heavy-duty vehicles. Structural analysis is done on the drum brake to validate the strength of the drum brake and thermal analysis is done to analyze the thermal properties. Comparison can be done for deformation; stresses, temperature etc. form the three materials to check which material is best. Catia is a 3d modeling software widely used in the design process. ANSYS is general-purpose finite element analysis (FEA) software package. Finite Element Analysis is a numerical method of deconstructing a complex system into very small pieces (of user-designated size) called elements.

Yield Strength of Line Pipe: Analysis of Forming Operations and Flattened Straps

2010 ◽  
Author(s):  
William J. Walsh ◽  
David Preston
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Bauschinger Effect ◽  
Material Model ◽  
Mechanical Tests ◽  
Specimen Preparation ◽  
Line Pipe ◽  
Apparent Modulus ◽  
Roll Bending ◽  
Tension And Compression

The effects of line pipe forming processes (Spiral, UOE, JCE, 3 Roll Bending, ERW) on steel yield strength are investigated by material modeling and mechanical testing. A model is developed for predicting the performance of a flattened transverse-body-tensile sample as typically performed by pipe mills for yield strength determination. Consideration is given to the Bauschinger effect, and hardening behavior to examine the resulting residual stress patterns through the wall thickness and the effect on measured yield strength. The pipe forming processes are modeled as pure bending and analyses are performed to determine how well this assumption simulates the actual operations. Tensile and compression testing is performed to establish the Bauschinger effect in both the tension and compression initial loading directions. The tensile data is incorporated into the material model. The model illustrates the progressive evolution of the residual stress pattern throughout the sequence of forming operations and specimen preparation. In addition, the residual curvature remaining in flattened tensile samples is analyzed and correlated with mechanical tests. The apparent modulus caused by curvature is shown to cause significant variation in the reported yield strength of linepipe.

Design of a lightweight automotive brake disc using finite element and Taguchi techniques

1998 ◽  
Vol 212 (4) ◽  
pp. 245-254 ◽  
Author(s):  
D. G. Grieve ◽  
D. C. Barton ◽  
D. A. Crolla ◽  
J. T. Buckingham
Keyword(s):  
Finite Element ◽  
Cast Iron ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Element Model ◽  
Sensitivity Study ◽  
Brake Disc ◽  
Lower Maximum ◽  
Aluminium Metal

Aluminium metal matrix composite brake discs offer significant weight advantages compared with the traditional cast iron rotor but have a much lower maximum operating temperature. In this study, a finite element model of an existing brake design is firstly used to predict the peak disc temperatures during two critical brake tests for both cast iron and an aluminium metal matrix composite alternative. A Taguchi analysis is then applied, enabling all the critical design and material factors of an aluminium metal matrix composite rotor to be considered collectively. Based on the results of this exercise, a parametric sensitivity study is carried out to define suitable design-material combinations for a prototype lightweight front brake disc to be used on small to medium passenger vehicles.

Mechanical Properties Identification of Viscoelastic/Hyperplastic Materials Using Haptic Device Based Experimental Setup

2011 ◽  
Vol 486 ◽  
pp. 115-118
Author(s):  
Alican Tabakci ◽  
Erhan Ilhan Konukseven
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Material Model ◽  
Force Sensor ◽  
Mechanical Tests ◽  
Haptic Device ◽  
Viscoelastic Materials ◽  
Test Setup ◽  
Element Modeling

Mechanical behavior simulation of viscoelastic materials is a difficult task. In order to obtain accurate simulations, material model should be well chosen and hyperelastic characteristics of the viscoelastic materials should also be incorporated in the model. Once the material model is selected the coefficients can be identified with the help of mechanical tests/experiments. The main goal of this study is to optimize material model’s coefficients by using the designed indenter test setup results and inverse finite element modeling. Indenter test setup was designed by using a haptic device, force sensor and data acquisition card to test the mechanical properties of the viscoelastic/hyperelastic materials. Inverse finite element modeling method is used in order to model the materials according to their material characteristics. The model obtained from the analysis was optimized by using the data obtained from indenter tests. The conformity of the chosen model and the tested materials is shown by inverse finite element modeling and the material model coefficients are proved to be identified correctly.

Study on “Single Factor” Material Model Used in Finite Element Simulation of High Speed Cutting of Mo-Cr Cast Iron

2010 ◽  
Vol 29-32 ◽  
pp. 365-369
Author(s):  
Yong Yang ◽  
Cheng Jun Chen ◽  
Chang He Li
Keyword(s):  
Finite Element ◽  
Cast Iron ◽  
Finite Element Simulation ◽  
High Speed ◽  
Factor Model ◽  
Material Model ◽  
Single Factor ◽  
High Speed Cutting ◽  
Material Parameters ◽  
Element Simulation

Theoretical analysis and material experiment are employed to study the “single factor” material model. Based on the dislocation theory, an analysis shows that material model is deeply affected by temperature. By the least squares best fit to experimental data, material parameters are found. Experiment curves analysis and material parameters comparison show that the material parameters of “single factor” model of Mo-Cr cast iron are temperature dependent. Using the mathematical mapping between material parameters and temperature, the “single factor” material model of Mo-Cr cast iron is established, which is proven to be right by comparing with experimental measurements. This work provides a useful insight for understanding the material model and helps to develop further finite element simulation of high speed cutting process of Mo-Cr cast iron.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

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.

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