Heat Built-Up of Industrial Solid Tires in Thailand

2013 ◽  
Vol 844 ◽  
pp. 445-449
Author(s):  
Sanae Rukkur ◽  
Charoenyut Dechwayukul ◽  
Wiriya Thongruang ◽  
Orasa Patarapaiboolchai
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Heat Generation ◽  
Strain Energy ◽  
High Speed ◽  
Cyclic Load ◽  
Hysteresis Loops ◽  
Heavy Load ◽  
Heat Build Up ◽  
Temperature Work

Solid tires made of natural rubber, manufactured and used for forklift trucks in Thailand, have quality problems involving blow out [. Failure of solid tires may occur from excessive loads and or heat generation inducing loss of mechanical properties. The failure of solid tires relating to heat generation is considered. Solid tires under severe conditions, such as overloading, high speed, or high temperature work places often leading to fail and blowout. When these are continuously rolled and loaded, the rubber is stressed and deformed leading to heat generation [. The hysteresis loss storage in form of strain energy due to internal friction in the rubber converts to the heat source transfer to the section of tire. During carrying heavy load, solid tire is subjected to the repeat compressed cyclic loading. Since rubber has the visco-hyperelastic property, cyclic load deformation causes hysteresis loop when tire is performed under cyclic load. Hysteresis loops area indicates the amount of energy turn into heat and it is difficult transferring to the surface of the tire due to insulation itself. As the results, there is heat build-up as shown in term of temperature rising differs in each tire and finally causes blowout or explosion.

scholarly journals Multiscale Collaborative Optimization of Processing Parameters for Carbon Fiber/Epoxy Laminates Fabricated by High-Speed Automated Fiber Placement

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenyu Han ◽  
Shouzheng Sun ◽  
Zhongxi Shao ◽  
Hongya Fu
Keyword(s):  
Mechanical Properties ◽  
Strain Energy ◽  
High Speed ◽  
Processing Parameters ◽  
Collaborative Optimization ◽  
Manufacturing Defects ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Processing Optimization ◽  
Carbon Fiber Epoxy

Processing optimization is an important means to inhibit manufacturing defects efficiently. However, processing optimization used by experiments or macroscopic theories in high-speed automated fiber placement (AFP) suffers from some restrictions, because multiscale effect of laying tows and their manufacturing defects could not be considered. In this paper, processing parameters, including compaction force, laying speed, and preheating temperature, are optimized by multiscale collaborative optimization in AFP process. Firstly, rational model between cracks and strain energy is revealed in order that the formative possibility of cracks could be assessed by using strain energy or its density. Following that, an antisequential hierarchical multiscale collaborative optimization method is presented to resolve multiscale effect of structure and mechanical properties for laying tows or cracks in high-speed automated fiber placement process. According to the above method and taking carbon fiber/epoxy tow as an example, multiscale mechanical properties of laying tow under different processing parameters are investigated through simulation, which includes recoverable strain energy (ALLSE) of macroscale, strain energy density (SED) of mesoscale, and interface absorbability and matrix fluidity of microscale. Finally, response surface method (RSM) is used to optimize the processing parameters. Two groups of processing parameters, which have higher desirability, are obtained to achieve the purpose of multiscale collaborative optimization.

Study on rheological properties of aviation lubricating oil under conditions of heavy load, high speed, and high temperature

2019 ◽  
Vol 71 (4) ◽  
pp. 525-531 ◽  
Author(s):  
Zhen Li ◽  
Xiaoli Zhao ◽  
Dezhi Zheng ◽  
Tingjian Wang ◽  
Le Gu ◽  
...  
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Rheological Model ◽  
High Speed ◽  
Traction Force ◽  
Lubricating Oil ◽  
Rheological Parameters ◽  
Heavy Load ◽  
Content Type ◽  
Loop Control

Purpose This study aims to evaluate the rheological properties of aviation lubricating oil under conditions of heavy load, high speed and high temperature and the applicability of the classical rheological model under severe conditions. Design/methodology/approach A Chinese aviation lubricating oil was used and its traction curves were obtained using a new two-disk tribotester. Its rheological parameters were calculated based on empirical formulae. Moreover, the traction force was calculated based on the classical Eyring rheological model. Findings The traction curves are obtained with respect to contact pressure, temperature and rolling speed. The rheological parameters are significantly influenced by environmental factors, especially viscosity. The traction force calculated using the Eyring model is consistent with the experimental results. Originality/value A novel two-disk tribotester was designed using a gas bearing and speed–force closed-loop control to ensure measurement accuracy. The mechanism of rheological properties was analyzed and the applicability of the classical rheological model under severe conditions was verified. It provided an experimental and theoretical basis for expanding the application of classical rheological models under extreme conditions.

Centrifugal Internal Grinding by Assembled Wheel with Radially Mobile Segments

2016 ◽  
Vol 874 ◽  
pp. 85-90 ◽  
Author(s):  
David Blurtsyan
Keyword(s):  
High Temperature ◽  
Heat Generation ◽  
Contact Area ◽  
High Speed ◽  
Air Flow ◽  
Grinding Wheel ◽  
Generation Zone ◽  
Internal Grinding ◽  
Turbulent Air Flow ◽  
Evacuation System

Productivity of internal grinding processes is limited by wheel-workpiece contact area and high temperature generated during grinding. Existing internal grinding methods do not guarantee presence of coolant liquid in the heat generation zone. Usually coolant liquid from external nozzles could not penetrate turbulent air flow around grinding wheel. Assembled wheel with radially mobile segments allows increasing contact area but needs to be supported by more efficient heat evacuation system. New grinding wheel and method of internal grinding are developed and evaluated. New tool generates high speed hydrodynamic circular flow and dynamic wedges of coolant liquid in the cutting zones.

Performance and Failure Modes of Grease Lubricated Hybrid Ceramic Bearing in High Speed and High Temperature Condition

2012 ◽  
Author(s):  
Dezhi Zheng ◽  
Le Gu ◽  
Tingjian Wang ◽  
Liqin Wang
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Failure Modes ◽  
Operating Conditions ◽  
Grease Lubrication ◽  
Operation Performance ◽  
Heavy Load ◽  
Ceramic Bearing ◽  
Rolling Element ◽  
Hybrid Silicon

Ceramic rolling element bearings have promising applications in extreme operating conditions such as high speed, high temperature, and heavy load. In this study, a hybrid silicon nitride ceramic ball bearing lubricated with high temperature grease is presented. The structure and parameters of the bearing are specially designed to satisfy the requirement of grease lubrication, high temperature and high speed conditions. A test rig was developed for the experiments of ceramic bearing performance. The experimental results show that grease lubricated ceramic bearings with fine design have excellent high speed and high temperature performance. By analyzing the operation performance and failure bearing inspection, the failure modes of grease lubricated ceramic bearings is analyzed. Thermal instability caused by the grease insufficient supply is the main factor of failure.

Effect of Mechanical Properties of Al2O3/(W,Ti)C Ceramic Tool Material on Its Tribological Characterization

2021 ◽  
Author(s):  
Limei Wang ◽  
Xiaorui Shi ◽  
Bo Wang ◽  
Hanlian Liu ◽  
Chuanzhen Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Friction Coefficient ◽  
High Speed ◽  
Cutting Tools ◽  
Tool Material ◽  
Ceramic Tool ◽  
Tool Materials ◽  
Ceramic Tool Material ◽  
Different Temperatures

Abstract Ceramic cutting tools are mainly used in high-speed dry machining, thus the tool material is in high temperature friction state with the workpiece material during cutting. The tribological characterizations have a direct impact on the cutting performance of the tool. Therefore, tribological characterizations of two kinds of ceramic tool materials with different mechanical properties against hardened steel H13 were compared at the same temperature, one material is Al2O3/(W,Ti)C/Ni with Ni(marked as AWTN), another is Al2O3/(W,Ti)C without Ni(marked as AWT). Also, the variation of tribological characterizations of AWT ceramic tool material with different temperatures was emphatically investigated. The results showed that the average friction coefficients of AWT and AWTN decreased with the increase of sliding speed under the same load, and the friction coefficient of AWT was lower than that of AWTN. Although AWTN material had better flexural strength and fracture toughness than AWT at ambient temperature, yet better hardness of AWT material both at room temperature and high temperature led to the lower friction coefficient and lower wear rate, indicating that the hardness had a greater impact on the wear of ceramic tool materials. The friction coefficient of AWT decreased with the increase of load and increased with the increase of temperature. The wear mechanism of Al2O3/(W,Ti)C ceramic tool material was different at different temperatures. The conclusion of this research had important guiding significance for the selection of cutting tools and cutting parameters in order to improve the machining quality.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

TEM Studies of Grain Boundary Films in Si3N4 Ceramics

1991 ◽  
Vol 49 ◽  
pp. 930-931
Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
Amorphous Film ◽  
Liquid Phase Sintering ◽  
Second Phase ◽  
High Temperature Mechanical Properties ◽  
Triple Points ◽  
Boundary Films

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.

AEM of reaction-bonded SiC

1992 ◽  
Vol 50 (1) ◽  
pp. 344-345
Author(s):  
K Das Chowdhury ◽  
R. W. Carpenter ◽  
W. Braue
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
High Temperature ◽  
Epitaxial Growth ◽  
Liquid Silicon ◽  
Structural Ceramic ◽  
Few Data

Research on reaction-bonded SiC (RBSiC) is aimed at developing a reliable structural ceramic with improved mechanical properties. The starting materials for RBSiC were Si,C and α-SiC powder. The formation of the complex microstructure of RBSiC involves (i) solution of carbon in liquid silicon, (ii) nucleation and epitaxial growth of secondary β-SiC on the original α-SiC grains followed by (iii) β>α-SiC phase transformation of newly formed SiC. Due to their coherent nature, epitaxial SiC/SiC interfaces are considered to be segregation-free and “strong” with respect to their effect on the mechanical properties of RBSiC. But the “weak” Si/SiC interface limits its use in high temperature situations. However, few data exist on the structure and chemistry of these interfaces. Microanalytical results obtained by parallel EELS and HREM imaging are reported here.

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