Forces and Energy in Circular Sawing and Grinding of Granite

2000 ◽  
Vol 123 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Xipeng Xu ◽  
Yuan Li ◽  
Stephen Malkin
Keyword(s):  
Normal Force ◽  
Tangential Force ◽  
Chip Thickness ◽  
Undeformed Chip Thickness ◽  
Unit Width ◽  
Wide Range ◽  
Grinding Conditions ◽  
Cutting Zone ◽  
Circular Sawing ◽  
Force Components

An investigation is reported of the forces and energy in circular sawing and grinding of gray granite. Measurements were made of the forces and power over a wide range of sawing and grinding conditions. Calculated tangential force components were found to be much different than the measured horizontal force components for sawing, but the two forces were almost identical for grinding. The location of the resultant force was proportionally further away from the bottom of the cutting zone with longer contact lengths. For sawing, the normal force per grain was nearly proportional to the calculated undeformed chip thickness. The G-ratios at different sawing rates reached a maximum value at the same intermediate undeformed chip thickness, which was attributed to a transition in the diamond wear mechanism from attrition to fracture at a critical normal force per grain. SEM observations indicated material removal mainly by brittle fracture, with some evidence of ductile plowing especially for grinding and to a lesser extent for sawing. The corresponding fracture energy was estimated to constitute a negligible portion of the total energy expenditure. About 30 percent of the sawing energy might be due to the interaction of the swarf with the applied fluid and bond matrix. Most of the energy for sawing and grinding is attributed to ductile plowing. Analogous to recent studies on grinding of ceramics and glass, the power per unit width was found to increase linearly with the generation of plowed surface area per unit width.

Sawing of Granite with Side-Slotted Diamond Segments

2006 ◽  
Vol 315-316 ◽  
pp. 103-107
Author(s):  
Yi Qing Yu ◽  
Y.F. Zhang ◽  
Yuan Li ◽  
Xi Peng Xu
Keyword(s):  
Normal Force ◽  
Tangential Force ◽  
Operating Parameters ◽  
Vertical Force ◽  
Cutting Zone ◽  
Circular Sawing ◽  
Diamond Saw ◽  
Force Components ◽  
Saw Blade ◽  
Resultant Forces

The present study was undertaken to examine the feasibility of circular sawing of granite with a newly shaped diamond saw blade. Three slots were formed on each side of each segment of the saw blade. Side-slotted segments and traditional segments were compared under same operating parameters. Measurements were made of the horizontal and vertical force components and the consumed power in order to obtain the tangential and normal force components. The surfaces of worn blade segments were examined by a scanning electron microscope. The consumed powers, normal and tangential force components for the side-slotted segments were found to be lower than those of the traditional segments. The position of resultant forces for the side-slotted segments is a little further away from the bottom of the cutting zone than the traditional segments. SEM observations indicated that the wear of the side-slotted segments was similar to sawing with traditional segments.

The Role of Grain Tip Radius in Fine Grinding

1975 ◽  
Vol 97 (3) ◽  
pp. 1119-1125 ◽  
Author(s):  
G. K. Lal ◽  
M. C. Shaw
Keyword(s):  
Grain Size ◽  
Surface Finish ◽  
Chip Thickness ◽  
Radius Of Curvature ◽  
Undeformed Chip Thickness ◽  
Fine Grinding ◽  
Abrasive Grains ◽  
Grinding Conditions ◽  
Tip Radius

The scratches produced by single abrasive grains in overcut fly milling show that the transverse shape of a grain is closely approximated by an arc of a circle. This radius of curvature is found to be independent of grain type and grinding conditions but varies with the grain size. The equation for undeformed chip thickness for surface grinding is rederived in terms of this radius. The important role that the transverse curvature of the grain plays relative to surface finish is also discussed.

Machining Forces: Some Effects of Removing a Wavy Surface

1966 ◽  
Vol 8 (2) ◽  
pp. 129-140 ◽  
Author(s):  
P. W. Wallace ◽  
C. Andrew
Keyword(s):  
Chip Thickness ◽  
Shear Plane ◽  
Shear Angle ◽  
Surface Slope ◽  
Experimental Conditions ◽  
Undeformed Chip Thickness ◽  
Cutting Force Components ◽  
The Mean ◽  
Force Components ◽  
Made In

Previous work has shown that during the removal of a surface waveform oscillating cutting force components arise which may have a phase difference with respect to the oscillating component of undeformed chip thickness; it has also shown that the shear angle is affected by the slopes of the surface waveform. However, no attempt to predict the oscillating force behaviour from the geometry of cutting has been reported. The present work attempts to achieve such a prediction by means of an analysis of the phase and magnitude of the oscillating force components acting in two directions; in the directions of the mean shear plane and of the tool rake face. In the analysis it is assumed that the shear angle oscillates in phase with and proportionally to the surface slope, and that the curvature of the chip varies with the undeformed chip thickness. An experimental technique for cutting with variable undeformed chip thickness is described, together with a method for recording and measuring the oscillating components of force and undeformed chip thickness. Experimental results are presented which show the assumptions made in the analysis to be substantially valid; the predicted oscillating forces are shown to be in adequate agreement with experiment over a range of experimental conditions. It is shown that the oscillation of the shear angle is primarily dependent on the surface slope and that the frictional force behaviour is consistent with the characteristics of the two regions of friction, sticking and sliding, as found in work on cutting with constant undeformed chip thickness.

A New Approach to Development of a Grinding Force Model

1987 ◽  
Vol 109 (4) ◽  
pp. 306-313 ◽  
Author(s):  
M. Younis ◽  
M. M. Sadek ◽  
T. El-Wardani
Keyword(s):  
Fiber Optics ◽  
Tangential Force ◽  
Chip Thickness ◽  
Grinding Wheel ◽  
Force Model ◽  
Stress Coefficient ◽  
Tangential Forces ◽  
Force Components ◽  
A New Technique ◽  
Loaded Area

A theoretical model has been developed for representing the grinding forces. This is based on the fact that the chip formation during grinding consists of three states: ploughing, cutting, and rubbing. Expressions for the total normal and tangential force components during these three stages were established. These components were expressed in terms of the chip thickness coefficient, the friction coefficient between the grit tip area and the workpiece, the stress coefficient arising during ploughing and, finally, the loading coefficient. The latter is expressed as an exponential in time. All these coefficients were determined experimentally by performing normal grinding tests at specified configurations. During these tests the forces were measured simultaneously with the loaded area on the grinding wheel during the process of grinding. The loaded area on the wheel surface was measured by a new technique using fiber-optics. This is based on the measurement of the reflectivity of the loaded particles. This system was calibrated by high magnification photographs taken of the surface texture. The predicted normal and tangential forces during the grinding process were compared with those experimentally obtained during the grinding tests mentioned earlier, showing reasonable agreement, both quantitatively and qualitatively.

scholarly journals Influence of Tangential Displacement on the Adhesion Force between Gradient Materials

2020 ◽  
Vol 65 (3) ◽  
pp. 205
Author(s):  
I. A. Lyashenko ◽  
Z. M. Liashenko
Keyword(s):  
Normal Force ◽  
Adhesion Force ◽  
Tangential Force ◽  
Adhesive Contact ◽  
Critical Force ◽  
Tangential Displacement ◽  
Optimal Parameters ◽  
Gradient Materials ◽  
Force Components ◽  
Adhesive Contacts

The influence of a tangential displacement on the strength of the adhesive contacts between gradient materials with different gradings of their properties has been studied. Variants with a controlled force (fixed load) and a controlled displacement (fixed grips) are considered. A relationship between the normal and tangential critical force components at which the contact is destroyed is obtained. It is valid within the whole interval of the gradient parameters, where the detachment criterium is obeyed. The optimal parameters at which the adhesive contact strength is maximum are determined. A case of detachment under the action of only the tangential force, i.e. when the normal force equals zero, is analyzed separately.

scholarly journals An investigation of force components in orthogonal cutting of medical grade cobalt–chromium alloy (ASTM F1537)

2017 ◽  
Vol 231 (4) ◽  
pp. 269-275 ◽  
Author(s):  
Szymon Baron ◽  
Eamonn Ahearne
Keyword(s):  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Lifestyle Changes ◽  
Ageing Population ◽  
Chromium Alloy ◽  
Cobalt Chromium ◽  
Undeformed Chip Thickness ◽  
Force Components ◽  
Medical Grade

An ageing population, increased physical activity and obesity are identified as lifestyle changes that are contributing to the ongoing growth in the use of in-vivo prosthetics for total hip and knee arthroplasty. Cobalt–chromium–molybdenum (Co-Cr-Mo) alloys, due to their mechanical properties and excellent biocompatibility, qualify as a class of materials that meet the stringent functional requirements of these devices. To cost effectively assure the required dimensional and geometric tolerances, manufacturers rely on high-precision machining. However, a comprehensive literature review has shown that there has been limited research into the fundamental mechanisms in mechanical cutting of these alloys. This article reports on the determination of the basic cutting-force coefficients in orthogonal cutting of medical grade Co-Cr-Mo alloy ASTM F1537 over an extended range of cutting speeds ([Formula: see text]) and levels of undeformed chip thickness ([Formula: see text]). A detailed characterisation of the segmented chip morphology over this range is also reported, allowing for an estimation of the shear plane angle and, overall, providing a basis for macro-mechanic modelling of more complex cutting processes. The results are compared with a baseline medical grade titanium alloy, Ti-6Al-4V ASTM F136, and it is shown that the tangential and thrust-force components generated were, respectively, ≈35% and ≈84% higher, depending primarily on undeformed chip thickness but with some influence of the cutting speed.

Effects of Different Types of Grinding Fluids on Grinding Force with a Semi-Empirical Based Model

2015 ◽  
Vol 809-810 ◽  
pp. 3-8 ◽  
Author(s):  
Guo Xu Yin ◽  
Ioan D. Marinescu ◽  
Michael Weismiller
Keyword(s):  
Process Parameters ◽  
Sliding Friction ◽  
Tangential Force ◽  
Grinding Force ◽  
Force Model ◽  
Grinding Process ◽  
Grinding Conditions ◽  
Force Components ◽  
Semi Empirical ◽  
Sliding Force

In present paper, a semi-empirical grinding force model is developed combined with the achievements of previous researchers by composing effects of normal and tangential grinding forces in two main parts respectively: cutting force and sliding force. Final equations for the total normal and tangential force components is established. This model is used to predict the total normal and tangential force in the surface grinding. These force components were expressed in terms of the grinding process parameters. There are four unknown coefficients in each equation which can be determined by experiment results at specific conditions with the variations of grinding process parameters. An equation for sliding force is established with the effect of specific sliding energy in terms of the experimental parameters. The average contact pressure and friction coefficient are taken into account. Four different water-based grinding fluids were tested for different specific grinding conditions. Low viscosity grinding fluid can have better performance than the high viscosity one due to the higher useful flow in the grinding contact area. The calculated normal and tangential grinding results are compared with the experimental ones. The verifications show that deviations can be affected by the performance of the fluid at heavy grinding conditions due to the sliding friction inside of rolling friction. To have a better agreement with experiment data. Shallow grinding condition is chosen to obtain the modified model.

Determining Undeformed Chip Thickness Models in Milling and its Verification during Wood Processing

2017 ◽  
Vol 265 ◽  
pp. 598-605 ◽  
Author(s):  
A.A. Fomin
Keyword(s):  
Chip Thickness ◽  
Processing Parameters ◽  
Energy Performance ◽  
Milling Process ◽  
Design Parameters ◽  
Chip Area ◽  
Undeformed Chip Thickness ◽  
Wood Processing ◽  
Wide Range ◽  
Cutter Design

This paper presents a mathematical model of the maximum thickness and the chip area for the processes of cylindrical and profile milling of various materials, including wood. The analytical dependences connecting the geometry of the shear layer with the elements of the milling mode and cutter design parameters are determined. Also, a model of the volume of material removed from the surface of the workpiece during the milling profile is presented. The comparative calculations of the previously known models and the models developed by the author were done. It was found that the models of the geometric parameters of cutting layer presented in the article are adequate and can be used to calculate the energy performance of the wood milling process with cylindrical and shaping cutters. These models are suitable for use in the calculations of the processing parameters for a wide range of material: metals, wood, plastic, glass and others.

Mechanisms for Sawing of Refractory Bricks with Diamond Blades

2009 ◽  
Vol 16-19 ◽  
pp. 1143-1148
Author(s):  
Yi Qing Yu ◽  
Yuan Li ◽  
Xi Peng Xu
Keyword(s):  
Specific Energy ◽  
Normal Force ◽  
Experimental Studies ◽  
Horizontal Force ◽  
Slurry Erosion ◽  
Diamond Grit ◽  
Circular Sawing ◽  
Force Components ◽  
Refractory Bricks ◽  
Spindle Power

Experimental studies were undertaken to investigate the mechanisms for circular sawing of refractory bricks with diamond segmented saw blades. Three kinds of diamond segments of different hardness were fabricated for the saw blades. The vertical and horizontal force components and the spindle power were measured in sawing. Based on the measurements of force and power, the specific energy and the normal force per diamond grit were obtained. The normal force per grit in the sawing of refractory bricks was found to be only 5% of the static compressive strength of diamonds used in the present study, but fractures of diamonds were still popular on the segment working surfaces after sawing. The power, horizontal force, and the specific energy were found to increase with segment hardness. The specific energy obtained from the measured power was basically comparable to the values obtained from a theoretical equation to calculate the specific energy associated with slurry erosion to the bond matrix of segments.

The Effects of Machining Parameters on the Position of Resultant Force in Sawing of Granite

2011 ◽  
Vol 487 ◽  
pp. 357-360
Author(s):  
Cong Fu Fang ◽  
Xi Peng Xu
Keyword(s):  
Relative Position ◽  
Normal Force ◽  
Resultant Force ◽  
Vertical Force ◽  
Machining Parameters ◽  
Circular Sawing ◽  
Force Components

The effects of the machining parameters on the relative position of the resultant force were analyzed in circular sawing of granite with a diamond segmented blade. The horizontal and vertical force components and the power were measured. Calculated tangential and normal force components were subsequently used to calculate the relative position of resultant force besides the horizontal and vertical force components. It was found that the value of the relative position of resultant force in down sawing is less than that in up sawing. The shift of sawing swarf has heavy influence on the relative position of resultant force.

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