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.

Identification of the Cutting Forces Coefficients via Milling Process Simulation

2011 ◽  
Author(s):  
Sergey A. Voronov ◽  
Igor A. Kiselev ◽  
Maxim G. Yakovlev
Keyword(s):  
Cutting Forces ◽  
Chip Thickness ◽  
Element Model ◽  
Optimization Method ◽  
Milling Process ◽  
Force Model ◽  
Processed Material ◽  
A New Technique ◽  
The Mathematical Model ◽  
The Given

The paper is devoted to the description of a new technique (numerical and experimental) identification of the dependences between cutting forces and instantaneous chip thickness. It is required to measure only the cutting forces versus cutting conditions. Experimentally, for the given pair the processed material – the tool, coefficients of the cutting forces model are calculated by means of the optimization method (Nelder-Mead algorithm). The mathematical model of the milling process developed by authors on each step of the Nelder-Mead method is used for the process numerical simulation under given coefficients of the cutting force model. The elaborated numerical modeling algorithm allows investigating the dynamics and the kinematics of the milling process. The dynamic model of the tool, the algorithm of geometrical modeling of the instantaneous chip thickness, the finite element model of the detail are embedded into the whole model of the milling process.

Cutting Force Changes during One Cut in End Milling with a Throw-Away Insert - Difference between Up-Cut and Down-Cut –

2019 ◽  
Vol 825 ◽  
pp. 123-128
Author(s):  
Kota Matsuda ◽  
Ryutaro Tanaka ◽  
Katsuhiko Sekiya ◽  
Keiji Yamada
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Tangential Force ◽  
Chip Thickness ◽  
Radial Force ◽  
Depth Of Cut ◽  
Radial Depth ◽  
Aisi 1045 ◽  
Tangential Forces ◽  
Coated Carbide

In this study, the transition of cutting force in the tangential and radial direction during one cut was investigated in milling of AISI-1045, AISI-304, and Ti-6Al-4V with a TiN coated carbide throw-away insert. In the case of 1045 and Ti-6Al-4V, there was not obvious difference in tangential forces between up-cut and down-cut. However, up-cut showed larger radial force than down-cut in any material. In down-cut, tangential force showed almost the same regardless of radial depth of cut. 304 and Ti-6Al-4V caused larger radial force with the increase of radial depth of cut at the same cut chip thickness.

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.

scholarly journals A New Grinding Force Model for Micro Grinding RB-SiC Ceramic with Grinding Wheel Topography as an Input

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 368 ◽  
Author(s):  
Zhipeng Li ◽  
Feihu Zhang ◽  
Xichun Luo ◽  
Xiaoguang Guo ◽  
Yukui Cai ◽  
...  
Keyword(s):  
Brittle Fracture ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Force Model ◽  
Sic Ceramics ◽  
Grinding Force Model ◽  
Proposed Model ◽  
Wheel Topography ◽  
Grinding Wheel Topography ◽  
Force Components

The ability to predict the grinding force for hard and brittle materials is important to optimize and control the grinding process. However, it is a difficult task to establish a comprehensive grinding force model that takes into account the brittle fracture, grinding conditions, and random distribution of the grinding wheel topography. Therefore, this study developed a new grinding force model for micro-grinding of reaction-bonded silicon carbide (RB-SiC) ceramics. First, the grinding force components and grinding trajectory were analysed based on the critical depth of rubbing, ploughing, and brittle fracture. Afterwards, the corresponding individual grain force were established and the total grinding force was derived through incorporating the single grain force with dynamic cutting grains. Finally, a series of calibration and validation experiments were conducted to obtain the empirical coefficient and verify the accuracy of the model. It was found that ploughing and fracture were the dominate removal modes, which illustrate that the force components decomposed are correct. Furthermore, the values predicted according to the proposed model are consistent with the experimental data, with the average deviation of 6.793% and 8.926% for the normal and tangential force, respectively. This suggests that the proposed model is acceptable and can be used to simulate the grinding force for RB-SiC ceramics in practice.

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.

Experimental study on force model in grinding of maraging steel 3J33

2018 ◽  
Vol 233 (10) ◽  
pp. 3475-3486
Author(s):  
Weicheng Guo ◽  
Beizhi Li ◽  
Shouguo Shen ◽  
Qinzhi Zhou
Keyword(s):  
Maraging Steel ◽  
Chip Thickness ◽  
Rayleigh Distribution ◽  
Grinding Force ◽  
Machining Process ◽  
Hertzian Contact ◽  
Force Model ◽  
Three Stages ◽  
Force Components ◽  
Validation Tests

Grinding is always a complicated machining process for joint interaction of numerous random abrasive grits in different chip formation processes. Therefore, analysis of grinding force requires a more comprehensive insight on the grinding mechanisms. This paper is devoted to propose an analytical force model in grinding of maraging steel 3J33 based on the fact that grinding process is divided into three stages, namely rubbing, ploughing and cutting, in terms of grits working status. These three stages are determined by the chip thickness model that is assumed to conform to Rayleigh distribution, in which the rubbing stage is derived from Hertzian contact theory. The experimental coefficients in the force model are calibrated by performing a set of training tests. The predicted normal and tangential grinding forces of the developed model are compared with those obtained from validation tests, which show favorable agreement quantitatively. The contributions of the grinding force components in different grit–workpiece interaction stages are obtained from the model and theirs relationships with process parameters are discussed.

A Time Domain Dynamic Simulation Model for Stability Prediction of Infeed Centerless Grinding Processes

2006 ◽  
Vol 129 (3) ◽  
pp. 539-550 ◽  
Author(s):  
Hongqi Li ◽  
Yung C. Shin
Keyword(s):  
Chip Thickness ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Force Model ◽  
Deformation Model ◽  
Two Dimensional ◽  
New Model ◽  
Grinding Processes ◽  
Centerless Grinding ◽  
Surface Profiles

This paper presents a comprehensive dynamic model that simulates infeed centerless grinding processes and predicts their instability-related characteristics. The new model has the unique ability of accurately predicting the coupled chatter and lobing process of a multi-degree of freedom and two-dimensional centerless grinding system by considering its critical issues. First, the model considers the complete two-dimensional kinematics, dynamics, surface profiles, and the geometrical interactions of the workpiece with the grinding wheel, regulating wheel, and supporting blade. Second, a two-dimensional distributed grinding force model along the contact length is adopted and modified for centerless grinding processes as a function of normalized uncut chip thickness. The forces of the work holding system are determined by balancing the grinding force and accordingly the work holding instability can be identified as well. Third, a two-dimensional contact deformation model under the condition of general surface profiles or pressure distributions is developed for the contacts of the workpiece with the grinding wheel, regulating wheel, and supporting blade. The new model is validated by comparing the predicted chatter and lobing occurrences with experimental results.

Forces during Grinding Operation and its Relation to the Dressing Cycle

2016 ◽  
Vol 1136 ◽  
pp. 78-83
Author(s):  
Anand Nambiar ◽  
Kou Matsumoto ◽  
Masaru Yamamoto ◽  
Kazuhito Ohashi ◽  
Shinya Tsukamoto
Keyword(s):  
Tangential Force ◽  
Dimensional Accuracy ◽  
Force Sensor ◽  
Grinding Wheel ◽  
Cutting Condition ◽  
Grinding Forces ◽  
Abrasive Particles ◽  
Force Variation ◽  
Grinding Machines ◽  
Force Components

While grinding with CNC cylindrical grinding machines, there are many factors that determine the precision and accuracy of the finished product. These may include dimensional accuracy, surface roughness, circularity (roundness), cylindricity, etc. But all these factors pertain to the work. The condition of the tool, in this case, the cutting edges of the grinding wheel, also greatly influence the profile and precision of the work. So, in order to maintain the precision of the work, there is a need to repeatedly and regularly maintain the cutting edges in a good cutting condition, by the process of dressing. In other words, when the swarf gets adhered to the grinding wheel, the abrasive particles can no longer perform machining with the same efficiency, due to increase in contact surface area between the abrasive particles and the work. This dissertation describes a technique that can be adopted to continuously monitor the grinding forces generated during the grinding operation, by using an in-process 2-dimensional piezoelectric force sensor, which can simultaneously measure the force and break it down into its two force components. The force sensor not only calculates the force generated, but also quantifies the force variation. By analyzing the variation in the radial and tangential force components individually, and by conducting Fourier analysis on the observed data, it is found that deterioration of the grinding wheel and the dress pattern can be continuously monitored and controlled.

scholarly journals Micromechanism of the Breakage of Two Spherical Gypsum Particles under Normal–Tangential Contact Conditions

2021 ◽  
Vol 11 (9) ◽  
pp. 4039
Author(s):  
Yiran Niu ◽  
Lin Li ◽  
Yanwei Zhang ◽  
Shicai Yu ◽  
Jian Zhou
Keyword(s):  
Tangential Force ◽  
Coarse Grained ◽  
Spherical Particles ◽  
Contact Conditions ◽  
Normal Contact ◽  
Tangential Contact ◽  
Theoretical Predictions ◽  
Tangential Forces ◽  
Predicted Values ◽  
The Relationship

Contact breakage of particles makes a large difference in the strength of coarse-grained soils, and exploring the characteristics within the process of the breakage is of great significance. Ignoring the influence of particle shape, the micromechanism of two spherical particles breaking under normal–tangential contact conditions was investigated theoretically and experimentally. Through theoretical analysis, the breakage form, the shape and size of the conical core, and the relationship between the normal and tangential forces at crushing were predicted. Particle contact tests of two gypsum spheres were carried out, in which the breakage forms, features of the conical cores and the normal and tangential forces at crushing were recorded for comparison with the predicted values. The test results and the theoretical predictions showed good agreement. Both the analysis and test demonstrate that the presence of tangential forces causes the conical core to assume the shape of an oblique cone, and the breakage form to change. Moreover, with increasing normal contact force, the tangential force needed for crushing increases gradually first and then decreases suddenly.

An Extension of CEB Elastic-Plastic Contact Model

2007 ◽  
Author(s):  
A. Sepehri ◽  
K. Farhang
Keyword(s):  
Contact Force ◽  
Tangential Force ◽  
Three Dimensional ◽  
Tangential Direction ◽  
Asperity Contact ◽  
Force Component ◽  
Normal Contact ◽  
Elastic Plastic ◽  
Force Components ◽  
Plastic Parts

Three dimensional elastic-plastic contact of two nominally flat rough surfaces is by developing the equations governing the shoulder-shoulder contact of asperities based on the Chang, Etsion and Bogy (CEB) model of contact in which volume conservation is assumed in the plastic flow regime. Shoulder-shoulder asperity contact yields a slanted contact force consisting of both tangential (parallel to mean plane) and normal components. Each force component comprises elastic and elastic-plastic parts. Statistical summation of normal force components leads to the derivation of the normal contact force for the elastic-plastic contact akin to the CEB model. Half-plane tangential force due to elastic-plastic contact is derived through the statistical summation of tangential force component along an arbitrary tangential direction.

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