620 High-Speed Deformation and Heat Generation of Metallic Materials

Purpose Thermal performances are key factors impacting the operation of angular contact ball bearings. Heat generation and transfer about angular contact ball bearings, however, have not been addressed thoroughly. So far, most researchers only considered the convection effect between bearing housings and air, whereas the cooling/lubrication operation parameters and configuration effect were not taken into account when analyzing the thermal behaviors of bearings. This paper aims to analyze the structural constraints of high-speed spindle, structural features of bearing, heat conduction and convection to study the heat generation and transfer of high-speed angular contact ball bearings. Design/methodology/approach Based on the generalized Ohm’s law, the thermal grid model of angular contact ball bearing of high-speed spindle was first established. Next Gauss–Seidel method was used to solve the equations group by Matlab, and the nodes temperature was calculated. Finally, the bearing temperature rise was tested, and the comparative analysis was made with the simulation results. Findings The results indicate that the simulation results of bearing temperature rise for the proposed model are in better agreement with the test values. So, the thermal grid model established is verified. Originality/value This paper shows an improved model on forecasting temperature rise of high-speed angular contact ball bearings. In modeling, the cooling/lubrication operation parameters and structural constraints are integrated. As a result, the bearing temperature variation can be forecasted more accurately, which may be beneficial to improve bearing operating accuracy and bearing service life.

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High-speed deformation and fracture of the dioxide-zirconium ceramics and zirconium alumina concrete

EPJ Web of Conferences ◽

10.1051/epjconf/20122601055 ◽

2012 ◽

Vol 26 ◽

pp. 01055 ◽

Cited By ~ 1

Author(s):

A. Bragov ◽

L. Kruszka ◽

A. Lomunov ◽

A. Konstantinov ◽

D. Lamzin ◽

...

Keyword(s):

High Speed ◽

Deformation And Fracture ◽

Zirconium Ceramics ◽

High Speed Deformation

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High-Speed Deformation of a High-Strength Coated Thin Plate

Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines ◽

10.20998/2078-9130.2015.57.72568 ◽

2015 ◽

Vol 1 (57) ◽

pp. 8-10

Author(s):

Lyudmila Vladimirovna Avtonomova ◽

Sergej Vladimirovich Bondar ◽

Aleksandr Vladimirovich Stepuk ◽

Valerij Lvovich Khavin

Keyword(s):

Thin Plate ◽

High Speed ◽

High Strength ◽

High Speed Deformation

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Analysis of Metallic Materials Behavior during Severe Loadings Using a FE Modeling of the SHPB Test Based on a Numerical Calibration of Elastic Strains with Respect to the Raw Measurements and on the Inverse Analysis Principle

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.554-557.1133 ◽

2013 ◽

Vol 554-557 ◽

pp. 1133-1146 ◽

Cited By ~ 1

Author(s):

Adinel Gavrus ◽

Florina Bucur ◽

Adrian Rotariu ◽

Sorin Cănănău

Keyword(s):

Finite Element ◽

Inverse Analysis ◽

High Speed ◽

Constitutive Behavior ◽

Metallic Materials ◽

Strain And Strain Rate ◽

Analysis Strategy ◽

Shpb Test ◽

Materials Behavior ◽

Elastic Strains

The complex loading paths of non-conventional or rapid forging processes, especially as regards the important gradients of the plastic strain and strain rate characterizing the material deformation, require a reliable knowledge of the rheological constitutive equations. Some recent studies propose adequate phenomenological formulations taking into account the corresponding local physical mechanisms and the sensitivity of the true stress with respect to all mechanical variables. At the same time important scientific efforts have been focused in order to identify correctly all the constitutive law parameters, using adequate mechanical tests and robust numerical tools based generally on the inverse analysis principle. It is known that this new method requires building of a rigorous and adequate experimental space, using data obtained from loading conditions close to the industrial forming process. Then to explore high variations of plastic strain and strain rate, one of the most suitable tests are based on high speed hydraulically press and on the Split Hopkinson Pressure Bars test (SHPB). Consequently this paper propose to improve the experimental data accuracy obtained from the SHPB device by using finite element simulations of the entire high speed mechanical experiment together with the description of the inverse analysis strategy applied in order to analyze the thermo-mechanical constitutive behavior of metallic materials behavior and to identify the corresponding rheological parameters. The first part of this study will be dedicated to a short description of the experimental SHPB test analysis and to the analysis of the measurement data which can be used to describe the real mechanical loadings of the specimen. A new experimental calibration method of the acquisition signals, based on the finite element modeling of the elastic bars deformation during an impact without specimen, will be detailed. Using ABAQUS and CAST3M software, this method is validated from the comparison of the elastic strains variation obtained by the numerical simulations. In a second part will be detailed the inverse analysis strategy together with a real application concerning the rheological behavior of an aluminum alloy using a “dumbbell” specimen during a high speed upsetting test starting from a proposed constitutive relationship. Finally, special “cap” geometries of the material sample will be analyzed during a SHPB compression test in order to understand the feasibility of the proposed method to expand the material constitutive behavior identification to severe loadings. It is then shown the capacity to describe deformation path close to the rapid manufacturing processes and high speed machining.

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Dynamics of Machine Tool Spindle/Bearing Systems Under Thermal Growth

Journal of Tribology ◽

10.1115/1.2833899 ◽

1997 ◽

Vol 119 (4) ◽

pp. 875-882 ◽

Cited By ~ 57

Author(s):

Bert R. Jorgensen ◽

Yung C. Shin

Keyword(s):

Thermal Expansion ◽

Dynamic Response ◽

Heat Generation ◽

High Speed ◽

Transfer Model ◽

Good Prediction ◽

High Speeds ◽

Spindle Bearing ◽

Thermal Growth ◽

Bearing Stiffness

Increased use of high-speed machining creates the need to predict spindle/bearing performance at high speeds. Spindle dynamic response is a function of the nonlinear bearing stiffness. At high speeds, thermal expansion can play an important role in bearing stiffness. A complete bearing load-deflection analysis including thermal expansion is derived and is coupled with an analysis of spindle dynamic response. Steady-state temperature distribution is found from heat generation at the contact point and from a quasi three-dimensional heat transfer model. Numerical solutions give a good prediction of thermal growth and heat generation in the bearing. Predicted high-speed spindle frequencies show good agreement with experimentation. The effects of loading condition and bearing material type on bearing stiffness are also shown.

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Investigation of Carbon Dioxide Based Blasting Technologies as Cryogenic Deburring Method for Titanium Alloy and Stainless Steel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.882.142 ◽

2018 ◽

Vol 882 ◽

pp. 142-153

Author(s):

Daniel Gross ◽

Andrea Heinz ◽

Sven Amon ◽

Trixi Meier ◽

Ralf Schmand ◽

...

Keyword(s):

Carbon Dioxide ◽

Stainless Steel ◽

Titanium Alloy ◽

High Speed ◽

Metallic Materials ◽

High Speed Video

This paper aims to expand the use of CO2blasting by investigating a cryogenic deburring method for machined metallic materials. In advance to the actual deburring experiments, a streaming analysis based on high-speed video records was conducted for different blasting technologies, in order to gain deeper knowledge about their underlying active principles. For the titanium alloy Ti-6Al-4V and the stainless steel X6CrNiMoTi17-12-2, deburring experiments with three different blasting techniques were conducted and evaluated. It has been shown that cryogenic deburring has the potential to represent an alternative deburring solution for metals.

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