The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Srečko Glodež - One of the best experts on this subject based on the ideXlab platform.
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computational model for determination of dynamic Load Capacity of large three row roller slewing bearings
Engineering Failure Analysis, 2013Co-Authors: Pete Goncz, Matej Drobne, Srečko GlodežAbstract:Abstract In the presented paper a calculation procedure for determination of dynamic Load Capacity of large three-row roller slewing bearings is presented. The calculation procedure consists of three main parts: (i) determination of internal contact force distribution in a large three-row roller slewing bearing with consideration of bearing clearances and ring support deformations, (ii) determination of stress field in the contact area between raceway and rollers as a consequence of contact forces and (iii) determination of the bearing’s fatigue life due to contact fatigue of the raceway. The internal contact force distribution is determined numerically by using a symmetry 3D FEM-model of a large three-row roller slewing bearing. Another numerical procedure is used to determine the stress field in the contact area between rollers and raceway. This problem is studied on different roller types: cylindrical roller (without profile correction), fully crowned roller (logarithmic-profile) and partially crowned roller (ZB-profile). Numerically determined contact stresses then serve as a basis for fatigue analyses, where the bearing’s service life of the bearing is determined by using the stress-life approach, considering typical material parameters of the bearing’s raceway.
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computational model for determination of static Load Capacity of three row roller slewing bearings with arbitrary clearances and predefined raceway deformations
International Journal of Mechanical Sciences, 2013Co-Authors: Pete Goncz, Rok Potocnik, Srečko GlodežAbstract:Abstract A new computational model for determination of internal contact forces distribution and consequently the determination of acceptable Load curves for static Load Capacity in three-row roller slewing bearings is presented in this paper. The proposed model considers some typical characteristics of large slewing bearings (possible structural ring deformations, non-parallel ring displacements, clearances, surface quenching of the raceway raceways, etc.) and their influence on the bearing static Capacity. For practical applicability of the model, vector approach is used for mathematical description of the bearing geometry and relative ring movements, together with the static force and moment equilibrium calculation. The model has been implemented into a computer code and it serves as a convenient engineering tool especially suitable for early stages of slewing bearings’ design. The proposed computational model has been used to determine the static Load Capacity of an actual three-row roller slewing bearing, where different geometric parameters, such as different predefined ring deformations, rollers sizes, roller profile modifications and tilted contact of rollers have been additionally analyzed. Computational analyses have shown that some of the investigated parameters have a significant influence on the static Load Capacity of analyzed slewing bearing.
Pete Goncz - One of the best experts on this subject based on the ideXlab platform.
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computational model for determination of dynamic Load Capacity of large three row roller slewing bearings
Engineering Failure Analysis, 2013Co-Authors: Pete Goncz, Matej Drobne, Srečko GlodežAbstract:Abstract In the presented paper a calculation procedure for determination of dynamic Load Capacity of large three-row roller slewing bearings is presented. The calculation procedure consists of three main parts: (i) determination of internal contact force distribution in a large three-row roller slewing bearing with consideration of bearing clearances and ring support deformations, (ii) determination of stress field in the contact area between raceway and rollers as a consequence of contact forces and (iii) determination of the bearing’s fatigue life due to contact fatigue of the raceway. The internal contact force distribution is determined numerically by using a symmetry 3D FEM-model of a large three-row roller slewing bearing. Another numerical procedure is used to determine the stress field in the contact area between rollers and raceway. This problem is studied on different roller types: cylindrical roller (without profile correction), fully crowned roller (logarithmic-profile) and partially crowned roller (ZB-profile). Numerically determined contact stresses then serve as a basis for fatigue analyses, where the bearing’s service life of the bearing is determined by using the stress-life approach, considering typical material parameters of the bearing’s raceway.
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computational model for determination of static Load Capacity of three row roller slewing bearings with arbitrary clearances and predefined raceway deformations
International Journal of Mechanical Sciences, 2013Co-Authors: Pete Goncz, Rok Potocnik, Srečko GlodežAbstract:Abstract A new computational model for determination of internal contact forces distribution and consequently the determination of acceptable Load curves for static Load Capacity in three-row roller slewing bearings is presented in this paper. The proposed model considers some typical characteristics of large slewing bearings (possible structural ring deformations, non-parallel ring displacements, clearances, surface quenching of the raceway raceways, etc.) and their influence on the bearing static Capacity. For practical applicability of the model, vector approach is used for mathematical description of the bearing geometry and relative ring movements, together with the static force and moment equilibrium calculation. The model has been implemented into a computer code and it serves as a convenient engineering tool especially suitable for early stages of slewing bearings’ design. The proposed computational model has been used to determine the static Load Capacity of an actual three-row roller slewing bearing, where different geometric parameters, such as different predefined ring deformations, rollers sizes, roller profile modifications and tilted contact of rollers have been additionally analyzed. Computational analyses have shown that some of the investigated parameters have a significant influence on the static Load Capacity of analyzed slewing bearing.
T Shitara - One of the best experts on this subject based on the ideXlab platform.
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axial Load Capacity of water lubricated hydrostatic conical bearings with spiral grooves for high speed spindles
Tribology International, 1998Co-Authors: Shigeka Yoshimoto, T Kume, T ShitaraAbstract:In this paper, two types of water-lubricated hydrostatic conical bearings with spiral grooves for high-speed spindles are investigated. One has a rigid bearing surface and the other has a compliant one. In these bearings, pressurized water is first fed to the inside of the rotating shaft and then introduced into spiral grooves through feeding holes. Therefore, water pressure is increased due to the effect of the centrifugal force at the outlets of the feeding holes by shaft rotation and, furthermore, water pressure is also increased by the viscous pump effect of spiral grooves. The static characteristics of these bearings are theoretically predicted and calculated results are compared with experimental results. It was found that the compliant surface bearing had a larger Load Capacity in a relatively large bearing clearance than the rigid surface bearing, and lower bearing power consumption in a small bearing clearance although the Load Capacity is reduced.
Leonardo M Massone - One of the best experts on this subject based on the ideXlab platform.
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investigation of the axial Load Capacity for lightly reinforced wall piers
Journal of Structural Engineering-asce, 2008Co-Authors: John W Wallace, Kenneth J Elwood, Leonardo M MassoneAbstract:A large number of reinforced concrete buildings constructed prior to the mid-1970s in western North America rely on lightly reinforced, perforated, perimeter shear walls to resist earthquake-induced lateral forces. Although a substantial number of piers may exist, deformation demands can significantly exceed acceptable levels for plastic deformations published in common acceptance criteria such as FEMA 356. A shear-friction model is used to establish the ability of wall piers to support vertical Loads after substantial loss of pier lateral-Load Capacity. The model results indicate that typical wall piers are capable of sustaining relatively large lateral drift ratios prior to loss of vertical Load-carrying Capacity, which is consistent with postearthquake observations. However, preliminary test results indicate that the drift Capacity may be substantially less for poorly detailed walls, where axial failure occurred at a lateral drift ratio of approximately one percent.
Li Tan - One of the best experts on this subject based on the ideXlab platform.
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approaching the upper bound of Load Capacity functional grading with interpenetrating polymer networks
Materials & Design, 2018Co-Authors: Zhong Chen, Mehrdad Negahban, Jean Marc Saiter, Nicolas Delpouve, Li TanAbstract:Abstract Functional grading is used to push the Load Capacity of parts to within the upper bound of what is theoretically possible. Using interpenetrating polymer networks (IPNs), a material system used to achieve grading during printing, the possibility of producing realistic grading of acrylate/epoxy IPNs is studied with the goal of increasing Load Capacity to within the limit of what is possible, and substantially beyond the Load Capacity possible with any uniform mixture of this IPN system. In the process, an upper bound of possible improvement is established for a plate with a circular hole in tensions, and the grading for this plate is adjusted to give an optimal Load Capacity near this upper bound. The optimal grading proposed is different from that shown in previous work due to the simultaneous consideration of both the effect of grading on elastic moduli and on the ultimate stress. A similar study was done for an L-shaped bracket indicating similar improvements over uniform brackets.
