Experimental Study and Finite Element Modeling of Workpiece Temperature in Finish Cylinder Boring

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Lei Chen ◽  
Bruce L. Tai ◽  
Juhchin A. Yang ◽  
Albert J. Shih
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Temperature Distribution ◽  
Heat Carrier ◽  
Machined Surface ◽  
Workpiece Temperature ◽  
Advantages And Disadvantages ◽  
Carrier Model ◽  
Inverse Heat Transfer ◽  
Cylindricity Error

Thermal expansion of the workpiece during cylinder boring process is one of the sources causing the bore cylindricity error. To study thermal expansion induced bore distortion, detailed workpiece temperature distribution in cylinder boring is required. Four finite element models, namely, the advection model, surface heat model, heat carrier model, and ring heat model, were developed to predict the workpiece temperature in cylinder boring. Cylinder boring experiments were conducted utilizing the tool–foil and embedded thermocouple experimental approaches to measure the workpiece temperature, predict the temperature distribution using the inverse heat transfer method, and evaluate the capability of the four models in terms of accuracy and efficiency. Results showed an accurate global temperature prediction for all models and a good correlation with the embedded thermocouple experimental measurements. Good correlation was also obtained between the tool–foil thermocouple measurement of machined surface temperature and model predictions. Advantages and disadvantages as well as applicable scenarios of each model were discussed. For studying detailed cylinder boring workpiece temperature, it is suggested to use the ring heat model to estimate the moving heat flux and the heat carrier model for local workpiece temperature calculation.

Finite Element Modeling of the Workpiece Thermal Distortion in MQL Deep-Hole Drilling

2011 ◽  
Author(s):  
Bruce L. Tai ◽  
Steven B. White ◽  
David A. Stephenson ◽  
Albert J. Shih
Keyword(s):  
Heat Flux ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Heat Carrier ◽  
Hole Drilling ◽  
Thermal Distortion ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Element Modeling ◽  
Carrier Model

This paper develops a three dimensional (3-D) finite element modeling (FEM) to predict the workpiece thermal distortion in minimum quantity lubrication (MQL) deep-hole drilling. Drilling-induced heat fluxes on the drilled hole bottom surface (HBS) and hole wall surface (HWS) are first determined by the inverse heat transfer method. The proposed 3-D heat carrier model consisting of shell elements to carry the HWS heat flux and solid elements to carry the HBS heat flux conducts the heat to the workpiece to mimic drilling process. A coupled thermal-elastic analysis is used to calculate the workpiece thermal distortion at each time step based on the temperature distribution. The heat carrier model is validated by comparing the temperature profiles at selected points with those from an existing 2-D axisymmetric advection model. The capability for modeling distortion in the case of drilling multiple deep-holes is also demonstrated.

Thermal Modeling of Workpiece Temperature in MQL Deep-Hole Drilling

2010 ◽  
Author(s):  
Bruce L. Tai ◽  
David A. Stephenson ◽  
Albert J. Shih
Keyword(s):  
Temperature Distribution ◽  
Minimum Quantity Lubrication ◽  
Hole Drilling ◽  
Bottom Surface ◽  
Transfer Model ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Workpiece Temperature ◽  
Inverse Heat Transfer ◽  
Inverse Solutions

This study investigates the workpiece temperature in minimum quantity lubrication (MQL) deep-hole drilling. An FEA-based inverse heat transfer model is developed to estimate the heat generation based on temperature inputs from embedded thermocouples. The temperature distribution in the workpiece is then calculated by the inverse solutions. The method is validated experimentally using a 10 mm carbide drill drilling cylindrical iron workpiece under both dry and MQL conditions. The calculated temperature distribution shows good agreement with experimental temperature measurements. This study demonstrates that the heat generated on the hole wall surface is as significant in workpiece temperature as that on the hole bottom surface in deep-hole drilling.

scholarly journals Heat Transfer Analysis in a Single Spool Gas Turbine by Using Calculated-Estimated Coefficients with the Finite Element Method

2020 ◽  
Vol 10 (23) ◽  
pp. 8328
Author(s):  
Geraldo Creci ◽  
Márcio Teixeira de Mendoça ◽  
João Carlos Menezes ◽  
João Roberto Barbosa
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Thermal Expansion ◽  
Temperature Distribution ◽  
Gas Turbine ◽  
The Finite Element Method ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Expansion Behavior

In this paper, a calculation procedure is presented to estimate the heat transfer coefficients of a single spool gas turbine designed to generate 5 kN of thrust. These heat transfer coefficients are the boundary conditions which govern the heat interaction between the solid parts and the working fluid in the gas turbine. However, the calculation of these heat transfer coefficients is not a trivial task, since it depends on complex fluid flow conditions. Empirical correlations and assumptions have been used to find convective heat transfer coefficients over most components, including stator vanes, rotor blades, disc faces, and disc platforms. After defining the heat transfer coefficients, the finite element method was used to determine the temperature distribution in one eighth section of the gas turbine making use of the problem cyclic symmetry. Both static and rotating assemblies have been modeled. The results allowed the prediction of the thermal expansion behavior of the whole single spool gas turbine with special attention to the safety margin of clearances. Furthermore, having the temperature distribution defined, it is possible to calculate the thermal stresses in any mechanical component. Additionally, it is possible to specify suitable metallic alloys for achieving appropriate performance in every case. The structural integrity of all components was then assured with the temperature distribution and thermal expansion behavior under knowledge. Thus, the mechanical drawings could be released to manufacturing.

A Finite Element Model for Temperature Prediction in Laser-Assisted Milling of AerMet100 Steel

2020 ◽  
Vol 977 ◽  
pp. 130-138
Author(s):  
Hao Hao Zeng ◽  
Rong Yan ◽  
Wei Wang ◽  
Peng Le Du ◽  
Tian Tian Hu ◽  
...  
Keyword(s):  
Finite Element ◽  
Surface Quality ◽  
Process Parameters ◽  
Incident Angle ◽  
Element Model ◽  
Fe Model ◽  
Temperature Prediction ◽  
Machined Surface ◽  
Workpiece Temperature ◽  
Machined Surface Quality

Laser-assisted milling (LAM) represents an innovative process to enhance productivity in comparison with conventional milling. The workpiece temperature in LAM not only affects the cutting performance of materials, but also the machined surface quality of the part. This paper presents a 3D transient finite element (FE) model for workpiece temperature prediction in LAM. A moving Gaussian laser heat source model is implemented as a user-defined subroutine and linked to ABAQUS. The thermal model is validated by machining AerMet100 steel under different process parameters (laser power, spindle speed and feed per tooth). Good agreement between predicted and measured workpiece temperatures indicates that the FE model is feasible. In addition, the effects of laser spot size and incident angle on workpiece temperature are analyzed based on the proposed model. This work can be further applied to optimize process parameters for controlling the machined surface quality in LAM.

Investigation of Finite Element Thermal Models for Workpiece Temperature in Cylinder Boring

2015 ◽  
Author(s):  
Lei Chen ◽  
Juhchin A. Yang ◽  
Albert J. Shih ◽  
Bruce L. Tai
Keyword(s):  
Finite Element ◽  
Heat Carrier ◽  
Computational Efficiency ◽  
Surface Heat ◽  
Computational Time ◽  
Depth Of Cut ◽  
Thermal Models ◽  
Workpiece Temperature ◽  
Fine Mesh ◽  
Computational Resources

The accuracy and computational efficiency of four finite element thermal models for workpiece temperature in cylinder boring are studied. High temperature in precision cylinder boring of automotive engine block can distort the workpiece, leading to thermally-induced dimensional and geometrical errors. In cylinder boring, the depth of cut is small compared to the bore diameter, so a fine mesh is usually needed to analyze the workpiece temperature distribution; however fine mesh on a relatively large workpiece also takes extensive computational resources. To understand the trade-off between accuracy and computational efficiency, the advection, surface heat, heat carrier, and ring heat finite element thermal models are introduced and compared quantitatively in a boring process. It is found comparable global temperature estimation from all four models. For the temperature near the cutting zone, the advection and surface heat models are more accurate to predict local temperatures but consume more computational resources. The heat carrier model predicts the surface temperature with reasonable accuracy and computational time. The ring heat model is the most computationally efficient but fails to accurately estimate local peak temperatures.

Spherical vs. Cylindrical Engine Bearings

2007 ◽  
Author(s):  
J. F. Booker ◽  
S. Boedo
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Temperature Distribution ◽  
Spherical Joint ◽  
Analysis Methods ◽  
Engine Design ◽  
Spherical Bearing

Spherical bearings have been used successfully in engines for some years. The spherical bearing geometry allows a simplified axisymmetric piston design; gradual rotation of the piston and rings results in axisymmetric sidewall wear, temperature distribution and thermal expansion. A previously-described concept engine design incorporating a spherical joint piston was based on an existing production engine with a conventional cylindrical piston pin. Previously-developed finite element lubrication analysis methods are applied to both designs and predictive comparisons made.

Bore Cylindricity in Finish Cylinder Boring

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Lei Chen ◽  
Juhchin A. Yang ◽  
Albert J. Shih
Keyword(s):  
Thermal Expansion ◽  
Fem Analysis ◽  
Machining Process ◽  
Error Sources ◽  
Workpiece Temperature ◽  
Coordinate Measurement ◽  
Radial Error ◽  
Cylinder Bore ◽  
Error Motion ◽  
Cylindricity Error

Finish boring is a machining process to achieve the cylinder bore dimensional and geometrical accuracy. The bore cylindricity error sources, including the workpiece thermal expansion and deformation due to cutting and clamping forces, and spindle radial error motion, in finish boring were identified using combined experimental and finite element method (FEM) analysis. Experiments were conducted to measure the workpiece temperature, cutting and clamping forces, spindle error, and bore shape. FEM analysis of the workpiece temperature, thermal expansion, and deformation due to cutting and clamping forces was performed. The coordinate measurement machine (CMM) measurements of the bore after finish boring showed the 5.6 μm cylindricity and a broad spectrum from the second to tenth harmonics. The FEM revealed the effects of workpiece thermal expansion (1.7 μm cylindricity), deformation due to cutting force (0.8 μm cylindricity), and clamping force (1.9 μm cylindricity) on the finished bore and the dominance by the first to third harmonics using the three-jaw fixture. The spindle synchronous radial error motion (3.2 μm cylindricity) was dominated by the fourth and higher order harmonics and matched well with the high (above the fourth) harmonics in CMM measurements (2.9 μm cylindricity). The spindle error was the dominant error source for bore cylindricity in this finish boring study, contributing to about half of the total cylindricity error.

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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