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Papers by hod mech
Automation and Autonomous System, 2011
Rolling bearings are used in great utility of machine elements such as rolling mill, textile mach... more Rolling bearings are used in great utility of machine elements such as rolling mill, textile machinery and air conditioner. Ball bearing stiffness is an important parameter in the design of machine components because of its effect on the performance of the system. The analysis of ball bearing is a complex process. The ball bearings are associated with nonlinearities such as mechanical gaps and the hertzian contacts between the rolling balls and the races. In this paper, an attempt is made to calculate the nonlinear stiffness of the outer raceway-rolling element- inner raceway system of standard ball bearing SKF 7305 BEP using FE techniques. The FE results are compared with the experimental and analytical results and are graphically represented. The results show a good agreement with the values calculated using Hertz relation.
Mechanics of Advanced Materials and Structures
In upset cold forging the existence of frictional constraints between the dies and the work piece... more In upset cold forging the existence of frictional constraints between the dies and the work piece directly affect the plastic deformation of the latter. The friction at the contact faces retards the plastic flow of metals and the surfaces and in its vicinity. A conical wedge of a relatively undeformed metal is formed suffers high strain hardening and bulges out in the form of barrel. This work has been taken up to generate data on the cold upset forging of square billets of annealed aluminium under dissimilar frictional conditions. Experiments were conducted by applying lubricant at one end of the square specimen and the other end with dry friction (with no lubrication). By the application of differential lubrication, a barrel and a truncated part near the unlubricated surfaces have been developed. The measured radius of curvature of the barrel was found to confirm with the calculated value. The calculations were made on the assumption that the curvature of the barrel followed the g...
Sadhana, 2015
This paper deals with simplified 3D finite element (FE) analysis on the effect of manufacturing t... more This paper deals with simplified 3D finite element (FE) analysis on the effect of manufacturing tolerances on the load carrying capacity of large diameter bearings based on Hertz theory. The nonlinear connector elements are used to model the rolling elements. This model enables us to evaluate the contact load on the rolling elements with relatively reduced calculation time. FE study has been carried out by allocating tolerance on balls and raceways using Monte Carlo simulation technique. The variation in dimension on balls is taken as per IS 2898-1976. A coding has been developed and employed for Monte Carlo simulation. Using the results of Monte Carlo simulation, tolerance has been assigned to the elements of large diameter bearing. From the results of finite element analysis, it is identified that analysis of large diameter bearing with tolerance on ball and raceway will lead to safe design.
Thermal analysis of ball bearings ought to be of core importance as the heat generated is dissipa... more Thermal analysis of ball bearings ought to be of core importance as the heat generated is dissipated by the slewing ring bearing. In this connection the thermal contact resistance (TCR) an important phenomenon that determines the heat dissipation of big bearings. The TCR values were collected by varying the applied loads, geometry, surface roughness and also the static friction coefficients were predicted by using conventional experiment. The above TCR and static coefficient of frictions experimental values were used to analyze the heat generation and heat distribution of big bearings by FLOTHERM software. The scope of this analysis relies in investigating the fatal effects of heat distribution and also relies in concepts on thermal analysis of big bearings for large scale applications like nuclear reactors, turbine and space vehicles.
Automation and Autonomous System, 2011
Rolling bearings are used in great utility of machine elements such as rolling mill, textile mach... more Rolling bearings are used in great utility of machine elements such as rolling mill, textile machinery and air conditioner. Ball bearing stiffness is an important parameter in the design of machine components because of its effect on the performance of the system. The analysis of ball bearing is a complex process. The ball bearings are associated with nonlinearities such as mechanical gaps and the hertzian contacts between the rolling balls and the races. In this paper, an attempt is made to calculate the nonlinear stiffness of the outer raceway-rolling element- inner raceway system of standard ball bearing SKF 7305 BEP using FE techniques. The FE results are compared with the experimental and analytical results and are graphically represented. The results show a good agreement with the values calculated using Hertz relation.
Mechanics of Advanced Materials and Structures
In upset cold forging the existence of frictional constraints between the dies and the work piece... more In upset cold forging the existence of frictional constraints between the dies and the work piece directly affect the plastic deformation of the latter. The friction at the contact faces retards the plastic flow of metals and the surfaces and in its vicinity. A conical wedge of a relatively undeformed metal is formed suffers high strain hardening and bulges out in the form of barrel. This work has been taken up to generate data on the cold upset forging of square billets of annealed aluminium under dissimilar frictional conditions. Experiments were conducted by applying lubricant at one end of the square specimen and the other end with dry friction (with no lubrication). By the application of differential lubrication, a barrel and a truncated part near the unlubricated surfaces have been developed. The measured radius of curvature of the barrel was found to confirm with the calculated value. The calculations were made on the assumption that the curvature of the barrel followed the g...
Sadhana, 2015
This paper deals with simplified 3D finite element (FE) analysis on the effect of manufacturing t... more This paper deals with simplified 3D finite element (FE) analysis on the effect of manufacturing tolerances on the load carrying capacity of large diameter bearings based on Hertz theory. The nonlinear connector elements are used to model the rolling elements. This model enables us to evaluate the contact load on the rolling elements with relatively reduced calculation time. FE study has been carried out by allocating tolerance on balls and raceways using Monte Carlo simulation technique. The variation in dimension on balls is taken as per IS 2898-1976. A coding has been developed and employed for Monte Carlo simulation. Using the results of Monte Carlo simulation, tolerance has been assigned to the elements of large diameter bearing. From the results of finite element analysis, it is identified that analysis of large diameter bearing with tolerance on ball and raceway will lead to safe design.
Thermal analysis of ball bearings ought to be of core importance as the heat generated is dissipa... more Thermal analysis of ball bearings ought to be of core importance as the heat generated is dissipated by the slewing ring bearing. In this connection the thermal contact resistance (TCR) an important phenomenon that determines the heat dissipation of big bearings. The TCR values were collected by varying the applied loads, geometry, surface roughness and also the static friction coefficients were predicted by using conventional experiment. The above TCR and static coefficient of frictions experimental values were used to analyze the heat generation and heat distribution of big bearings by FLOTHERM software. The scope of this analysis relies in investigating the fatal effects of heat distribution and also relies in concepts on thermal analysis of big bearings for large scale applications like nuclear reactors, turbine and space vehicles.