scholarly journals Temperature evolution of the train brake disc during high-speed braking

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881956
Author(s):  
Zhizhong Wang ◽  
Jianmin Han ◽  
Xiaolong Liu ◽  
Zhiqiang Li ◽  
Zhiyong Yang ◽  
...  
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Temperature Variation ◽  
Friction Surface ◽  
High Speed ◽  
Experimental Results ◽  
Temperature Evolution ◽  
Maximum Temperature ◽  
Brake Disc ◽  
In Situ Experiments

Temperature evolution of the train brake disc during high-speed braking was investigated using in situ experiments, theoretical analysis, and finite element modeling. The experimental results show that the temperature distribution on the friction surface experienced the formation of a hot ring first, then expansion and duration of the hot ring. Alternative hot spot and cold zone were observed on the friction surface, which is attributed to the local contact in the friction couple and heterogeneous heat dissipation condition in the disc. The corresponding maximum temperature in the disc increased rapidly first, kept stable then, and decrease slowly in the end. The one-dimensional heat conduction equation was applied to predict the maximum temperature variation and was found to be in agreement with the experimental results. Furthermore, the maximum temperature evolution and the temperature distribution of the disc at the braking time of 45 s were simulated by the finite element method, which is satisfactory. In additional, the temperature variation caused the corresponding fluctuation of instantaneous frictional coefficient and thermal stress distribution in the disc, which results in the thermal damages.

Three-Dimensional Finite Element Analysis in Cutting Temperature for High Speed Milling of Titanium Alloys

2011 ◽  
Vol 189-193 ◽  
pp. 2259-2263
Author(s):  
You Xi Lin ◽  
Cong Ming Yan
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Titanium Alloys ◽  
High Speed ◽  
Three Dimensional ◽  
Cutting Temperature ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth

A three dimensional fully thermal-mechanical coupled finite element model had been presented to simulate and analyze the cutting temperature for high speed milling of TiAl6V4 titanium alloy. The temperature distribution induced in the tool and the workpiece was predicted. The effects of the milling speed and radial depth of cut on the maximum cutting temperature in the tool was investigated. The results show that only a rising of temperature in the lamella of the machined surface is influenced by the milling heat. The maximum temperature in the tool increases with increasing radial depth of cut and milling speed which value is 310°C at a speed of 60 m/min and increases to 740°C at 400m/min. The maximum temperature is only effective on a concentrated area at the cutting edge and the location of the maximum temperature moves away from the tool tip for higher radial depths of milling. The predicted temperature distribution during the cutting process is consistent with the experimental results given in the literature. The results obtained from this study provide a fundamental understanding the process mechanics of HSM of titanium alloys.

EXPERIMENTAL AND NUMERICAL STUDY OF THERMAL ANALYSIS OF HIGH-SPEED FRICTION BRAKING SYSTEM

2011 ◽  
Vol 10 (01) ◽  
pp. 135-142
Author(s):  
CHUNMEI ZHANG ◽  
YONGFENG LI
Keyword(s):  
Thermal Analysis ◽  
Friction Surface ◽  
High Speed ◽  
Material Selection ◽  
Numerical Study ◽  
Friction Pair ◽  
Maximum Temperature ◽  
Dimensionless Time ◽  
Braking System ◽  
Friction Braking System

Thermal analysis can be used as one of the basis for the friction pair material selection in high-speed friction braking system. In this study, the experimental results showed that surface temperature could be reduced by increasing the radius of the friction disk or thermal conductivity coefficient of disk material with stable braking; In the early stage of long braking, the temperature on the friction surface rises rapidly, but further braking does not lead to a significant rise in temperature; In the case of short braking, there is not enough time for the friction surface to reach the critical temperature, and the disk surface reaches the maximum temperature at the end of braking. During long braking, the dimensionless time capacity of the friction surface reaching the highest temperature is F0 ≈ 0.1F0s.

scholarly journals Thermal distribution analysis of inner defects in TSV

2018 ◽  
Vol 38 ◽  
pp. 04026
Author(s):  
Chuan Kai Jiang ◽  
Lei Nie ◽  
Wen Jia ◽  
Yu Ning Zhong
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Temperature Distribution ◽  
Temperature Variation ◽  
Finite Element Models ◽  
Distribution Analysis ◽  
Internal Defects ◽  
External Temperature ◽  
Thermal Distribution ◽  
Distinct Temperature

In order to uncover the external manifestations of TSV internal defects, the finite element models of typical internal defects, which were filling missing, axial cavity and end cavity, were established. The thermal analysis was carried out using thermoelectric coupling method. The temperature distribution of TSV with and without defects were obtained. And the temperature variation profiles on the defined paths of TSV layer were also analyzed. The analysis indicated that all the defective TSV showed distinct temperature distribution with the defect-free TSV. Among three typical defects, TSV with filling missing showed the most obvious difference on the temperature distribution and path variation. TSV with end cavity has relatively weak affect and the slightest defect was TSV with axial cavity. Therefore, it could be seen that the external temperature difference caused by the internal defects of TSV could provide effective information for the identification and detection in TSV with internal defects.

Effects of radial aerodynamic forces on rotor-bearing dynamics of high-speed turbochargers

2014 ◽  
Vol 228 (14) ◽  
pp. 2503-2519 ◽  
Author(s):  
A Alsaeed ◽  
G Kirk ◽  
S Bashmal
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Element Model ◽  
Pressure Variation ◽  
Experimental Results ◽  
Aerodynamic Forces ◽  
Aerodynamic Loads ◽  
Numerical Predictions ◽  
Reaction Forces ◽  
Bearing Dynamics

This study investigates the radial aerodynamic forces that may develop inside the centrifugal compressor and the turbine volutes due to pressure variation of the circulating gas. The forces are numerically predicted for magnitudes, directions, and locations. The radial aerodynamic forces are numerically simulated as static forces in the turbocharger finite element model with floating ring bearings and solved for nonlinear time-transient response. The numerical predictions of the radial aerodynamic forces are computed with correlation to earlier experimental results of the same turbocharger. The outcomes of the investigation demonstrate a significant influence of the radial aerodynamic loads on the turbocharger dynamic stability and the bearing reaction forces. The numerical predictions are also compared with experimental results for validation.

scholarly journals Experiment and Analysis of Cord Stress on High-Speed Radial Tire Standing Waves

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Peng-Fei Sun ◽  
Hong-Wu Huang ◽  
Shui-Ting Zhou ◽  
Yi-Jui Chiu ◽  
Meng Du ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Standing Waves ◽  
Element Model ◽  
Experimental Results ◽  
Radial Tire ◽  
Oblique Wave ◽  
Vehicle Velocity ◽  
The Finite Element Model

This paper elaborates on the production mechanisms of standing waves during high-speed tire rolling and analyzes the relationship between the change of wavelength of sidewall waves and the vehicle velocity, from an oblique wave point of view. A finite element model for a 195/65R15 radial tire is established with the nonlinear analysis software ABAQUS, based on the tire structure and cord parameters. This paper comparatively analyzes the finite element simulation results and experimental results of the tire load-sinkage relation and the load vs inflatable section width relation and finds little difference between the simulation and experimental results. A similar analysis studies the change in the wavelength of sidewall standing waves at different vehicle velocities during high-speed tire rolling. The calculated value by the oblique wave approach, the value by simulation, and the experimental results demonstrate high consistency, concluding that during high-speed tire rolling, the wavelength of sidewall standing waves increases with vehicle velocity. Thus, the accuracy of the finite element model is verified under both static and dynamic conditions. Under a constant tire pressure and load, the impact of velocity change on tire-cord stress during high-speed tire rolling is studied based on the finite element model so as to identity the relation between the cord stress and standing waves.

A New Method for Temperature Measurement to Determine the Temperature Variation in Cylindrical Grinding Contact Arc

2010 ◽  
Vol 139-141 ◽  
pp. 762-767
Author(s):  
Bei Zhi Li ◽  
Da Hu Zhu ◽  
Jing Zhu Pang ◽  
Zhen Xin Zhou ◽  
Jian Guo Yang
Keyword(s):  
Temperature Measurement ◽  
Temperature Variation ◽  
High Speed ◽  
New Method ◽  
Maximum Temperature ◽  
Depth Of Cut ◽  
Measured Temperature ◽  
Plunge Grinding ◽  
Temperature Signal ◽  
Contact Arc

Due to the difficulty in arrangement of thermocouples, temperature measurement in grinding presents a number of challenges, particularly in high speed cylindrical-plunge grinding. Based on existing literature, only single thermocouple is considered for measuring the maximum temperature in the grinding contact arc, without considering the overall temperature variation. In this paper, a new method for temperature measurement, named four K-type thermocouples, is proposed aslant along the direction of the width of workpiece which is developed for measuring the overall contact arc in high speed cylindrical-plunge grinding. It is shown that the temperature increases to the maximum with a sharp gradient, then decreases due to the strengthening of cooling effect and the decrease of depth of cut, which is consistent with previous study. The measured temperature signal reveals the generation rule and dissipation rule of grinding heat.

Bearing Loads Study for High-Speed Motorized Spindle

2011 ◽  
Vol 480-481 ◽  
pp. 1511-1515
Author(s):  
Dong Man Yu ◽  
Chang Pei Shang ◽  
Di Wang ◽  
Zhi Hua Gao
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Dynamic Stiffness ◽  
Element Model ◽  
Basic Structure ◽  
Maximum Temperature ◽  
Motorized Spindle ◽  
Finite Element Software ◽  
Bearing Loads ◽  
Precision Machine Tools

Due to high rotation accuracy, high dynamic stiffness, high vibration damping and long life, high-speed spindles supported by hydrodynamic and hydrostatic hybrid bearings are widely applied in the field of high-speed precision machine tools. The basic structure and working principal was detailed introduced, and then demonstrated a series of models and specifications of motorized spindle manufactured by FISCHER company in Switzerland. The finite element model of high-speed motorized spindle was built up and carried out thermal analysis to study the heat generation and heat transfer. With the help of ANSYS finite element software, the temperature field distribution and the temperature rise condition for motorized spindle were analyzed. The result indicates that the front bearing has a higher temperature than that of back bearing. The maximum temperature of inner ring is bigger than that of outer ring.

scholarly journals Numerical Thermal Analysis of a T Jump System Used for Studying Polymer Behaviour

2019 ◽  
Vol 890 ◽  
pp. 155-161
Author(s):  
Sara Gomes ◽  
Paula Pascoal-Faria ◽  
Geoffrey R. Mitchell ◽  
Thomas Gkourmpis ◽  
Tristan Youngs
Keyword(s):  
Thermal Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Temperature Variation ◽  
Element Model ◽  
Maximum Temperature ◽  
Molecular Organisation

The processing of polymers is highly complex. The study of their crystallisation assumes an important role and needs to be carefully detailed. Scattering experiments can be used to study polymer molecular organisation. However these procedures are still very multifaceted leading to the need for planning all the details in the experiments that are to be performed. This manuscript presents a finite element model developed to study the temperature variation of a T Jump System, which has been used for studying polymer behaviour with the NIMROD instrument at the ISIS Neutron and Muon Source, UK. Results show that the variation across the sample was 2oC at a maximum temperature of 70oC and 1oC at a maximum temperature of 50oC.

scholarly journals Design Synchronous Generator Using Taguchi-Based Multi-Objective Optimization

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3337
Author(s):  
Ruiye Li ◽  
Peng Cheng ◽  
Yingyi Hong ◽  
Hai Lan ◽  
He Yin
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Optimization Algorithm ◽  
Continuous Optimization ◽  
Element Model ◽  
Optimization Method ◽  
Geometric Parameters ◽  
Maximum Temperature ◽  
Design Decision ◽  
Multi Objective

The extensive use of finite element models accurately simulates the temperature distribution of electrical machines. The simulation model can be quickly modified to reflect changes in design. However, the long runtime of the simulation prevents any direct application of the optimization algorithm. In this paper, research focused on improving efficiency with which expensive analysis (finite element method) is used in generator temperature distribution. A novel surrogate model based optimization method is presented. First, the Taguchi orthogonal array relates a series of stator geometric parameters as input and the temperatures of a generator as output by sampling the design decision space. A number of stator temperature designs were generated and analyzed using 3-D multi-physical field collaborative finite element model. A suitable shallow neural network was then selected and fitted to the available data to obtain a continuous optimization objective function. The accuracy of the function was verified using randomly generated geometric parameters to the extent that they were feasible. Finally, a multi-objective genetic optimization algorithm was applied in the function to reduce the average and maximum temperature of the machine simultaneously. As a result, when the Pareto front was compared with the initial data, these temperatures showed a significant decrease.

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