scholarly journals Thermal Analysis and Impart of Temperature Distribution on the Performance of Additive Manufactured Titanium Alloy Based Composite Coatings

2021 ◽  
Vol 309 ◽  
pp. 01152
Author(s):  
O.S. Fatoba ◽  
S.A. Akinlabi ◽  
E.A. Mekonen ◽  
B.A. Tadesse ◽  
E.T. Akinlabi

Finite element numerical analysis can be used to solve problems of boundary values. The accuracy of model is depended on the meshing refinement. In aerospace industry, finite element analysis has been used by several researchers to know the influence of temperature distribution on the performance of additive manufactured component parts. Accuracy is better with finer mesh. Complex nature of the additive manufacturing process due to rapid heating and cooling made many researchers to adopt numerical investigation which is made easier than the experimental method. Proper modelling of the process must be thoroughly done for the numerical modelling results to be analyzed. The experiment of ternary titanium alloy of Ti-Al-Si-Cu was carried out with cladding machine of 3000 Watts (CW) Ytterbium Laser System (YLS-2000-TR). This machine is situated at the National Laser Centre in the Council of Scientific and Industrial Research (NLC-CSIR). The characterization was done using the standardization ASTM E3-11 procedure. The results shiw the impart of temperature distribution on the dendritic arm spacing in the microstructures. The rate of cooling imparts on the space between the dendritic arms. The more the space, the more the influence on the coating’s properties

1971 ◽  
Vol 6 (2) ◽  
pp. 89-98 ◽  
Author(s):  
T R Gurney

By means of a form of finite-element analysis and use of a theoretical, radially symmetrical, temperature distribution, the residual stresses resulting from spot heating at the centre of a large circular plate have been calculated. The investigation was concerned in particular with defining the effect of variations in material yield stress, rate of heat input, and peak temperature on the residual-stress distribution.


2008 ◽  
Vol 36 (1) ◽  
pp. 63-79 ◽  
Author(s):  
L. Nasdala ◽  
Y. Wei ◽  
H. Rothert ◽  
M. Kaliske

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.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2760
Author(s):  
Ruiye Li ◽  
Peng Cheng ◽  
Hai Lan ◽  
Weili Li ◽  
David Gerada ◽  
...  

Within large turboalternators, the excessive local temperatures and spatially distributed temperature differences can accelerate the deterioration of electrical insulation as well as lead to deformation of components, which may cause major machine malfunctions. In order to homogenise the stator axial temperature distribution whilst reducing the maximum stator temperature, this paper presents a novel non-uniform radial ventilation ducts design methodology. To reduce the huge computational costs resulting from the large-scale model, the stator is decomposed into several single ventilation duct subsystems (SVDSs) along the axial direction, with each SVDS connected in series with the medium of the air gap flow rate. The calculation of electromagnetic and thermal performances within SVDS are completed by finite element method (FEM) and computational fluid dynamics (CFD), respectively. To improve the optimization efficiency, the radial basis function neural network (RBFNN) model is employed to approximate the finite element analysis, while the novel isometric sampling method (ISM) is designed to trade off the cost and accuracy of the process. It is found that the proposed methodology can provide optimal design schemes of SVDS with uniform axial temperature distribution, and the needed computation cost is markedly reduced. Finally, results based on a 15 MW turboalternator show that the peak temperature can be reduced by 7.3 ∘C (6.4%). The proposed methodology can be applied for the design and optimisation of electromagnetic-thermal coupling of other electrical machines with long axial dimensions.


Author(s):  
Oscar O. Rodriguez ◽  
Arturo A. Fuentes ◽  
Constantine Tarawneh ◽  
Robert E. Jones

Thermoplastic elastomers (TPE’s) are increasingly being used in rail service in load damping applications. They are superior to traditional elastomers primarily in their ease of fabrication. Like traditional elastomers they offer benefits including reduction in noise emissions and improved wear resistance in metal components that are in contact with such parts in the railcar suspension system. However, viscoelastic materials, such as the railroad bearing thermoplastic elastomer suspension element (or elastomeric pad), are known to develop self-heating (hysteresis) under cyclic loading, which can lead to undesirable consequences. Quantifying the hysteresis heating of the pad during operation is therefore essential to predict its dynamic response and structural integrity, as well as, to predict and understand the heat transfer paths from bearings into the truck assembly and other contacting components. This study investigates the internal heat generation in the suspension pad and its impact on the complete bearing assembly dynamics and thermal profile. Specifically, this paper presents an experimentally validated finite element thermal model of the elastomeric pad and its internal heat generation. The steady-state and transient-state temperature profiles produced by hysteresis heating of the elastomer pad are developed through a series of experiments and finite element analysis. The hysteresis heating is induced by the internal heat generation, which is a function of the loss modulus, strain, and frequency. Based on previous experimental studies, estimations of internally generated heat were obtained. The calculations show that the internal heat generation is impacted by temperature and frequency. At higher frequencies, the internally generated heat is significantly greater compared to lower frequencies, and at higher temperatures, the internally generated heat is significantly less compared to lower temperatures. However, during service operation, exposure of the suspension pad to higher loading frequencies above 10 Hz is less likely to occur. Therefore, internal heat generation values that have a significant impact on the suspension pad steady-state temperature are less likely to be reached. The commercial software package ALGOR 20.3TM is used to conduct the thermal finite element analysis. Different internal heating scenarios are simulated with the purpose of obtaining the bearing suspension element temperature distribution during normal and abnormal conditions. The results presented in this paper can be used in the future to acquire temperature distribution maps of complete bearing assemblies in service conditions and enable a refined model for the evolution of bearing temperature during operation.


2017 ◽  
Vol 4 (2) ◽  
pp. 957-965
Author(s):  
Chadaram Srinivasu ◽  
Swadesh Kumar Singh ◽  
Gangadhar Jella ◽  
Lade Jayahari ◽  
Nitin Kotkunde

2012 ◽  
Vol 522 ◽  
pp. 245-248 ◽  
Author(s):  
Hai Tao Liu ◽  
Ya Zhou Sun ◽  
De Bin Shan ◽  
Yan Quan Geng

There are lots of titanium alloy parts which have large-scale micro-structures in astronautic structure and medical implants, so the micro milling becomes one of the effective processing methods in getting the surface micro-structure. Because the titanium alloy has high caking property in processing, it needs a research on the cutting heat and force in order to get better machining precision and surface quality. According to the finite element theory in elastic and plasticity, the influence of cutting speed to the cutting heat and force is got by finite element simulation analysis to the titanium material TC4 in cutting process. It can get the simulation results of cutting heat and force in the micro milling processing by finite element analysis, and then compared, the basic influence which the cutting speed to the cutting heat and force is got. The correctness of the result is checked through cutting experiments.


2020 ◽  
Vol 111 (7-8) ◽  
pp. 1929-1940 ◽  
Author(s):  
Zhongyuan Feng ◽  
Ninshu Ma ◽  
Wangnan Li ◽  
Kunio Narasaki ◽  
Fenggui Lu

AbstractFinite element analysis is commonly used to investigate the thermal-mechanical phenomena during welding. To improve the computing efficiency of finite element analysis for welding thermal conduction, a novel Newton–Raphson method (NRM) without the computation of inverse matrix and a hybrid method combing the NRM and conventional implicit method (IMP) were developed. Comparison of computing time between the hybrid method implemented in an in-house software JWRIAN and the IMP used in a commercial software ABAQUS indicated that the computing speed of the former was about 4.5 times faster than that of the latter. Additionally, compared to the conventional IMP, the NRM exhibited higher computing efficiency in the analysis of transient thermal conduction during the welding heating process. Meanwhile, a combined hybrid method of the NRM and IMP was verified to be more efficient in analyzing the welding thermal conduction throughout the heating and cooling processes. Moreover, the thermal cycles computed by the hybrid method were consistent with those from experimental measurement, indicating the high accuracy of the hybrid method. Furthermore, the hybrid method was used to predict the temperature field of the corner boxing fillet joint welded by a low transformation temperature weld metal for generation of compressive residual stress.


2019 ◽  
Vol 22 (3) ◽  
pp. 324-330 ◽  
Author(s):  
Prashant Jindal ◽  
Frank Worcester ◽  
Kartikeya Walia ◽  
Anand Gupta ◽  
Philip Breedon

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