Dynamic Model of Material Removal Process in Through-Feed Centerless Grinding Based on the Lagrange Equation

2015 ◽  
Vol 667 ◽  
pp. 173-180 ◽  
Author(s):  
Cui Qi ◽  
Shi Jin Chen ◽  
Hui Ding ◽  
Kai Cheng
Keyword(s):  
Material Removal ◽  
Lagrange Equation ◽  
Grinding Wheel ◽  
Removal Process ◽  
3D Space ◽  
Centerless Grinding ◽  
Control Wheel ◽  
Geometric Relationship ◽  
And Control ◽  
Relationship Of

Due to the unfixed state of the workpiece and the dissimilarity between sections in through-feed centerless grinding, the positions and orientations of the workpiece keep changing in the grinding process, which are coupled with the workpiece roundness generation. In this paper the positions and orientations of the workpiece are described by the dynamic equations obtained from Lagrange equation. And the homogeneous coordinate transformation is applied to present the profiles of the workpiece, grinding wheel and control wheel in the reference frame. Finally the time varying profile of the workpiece is obtained for the investigation of the material removal process in 3D space. The material properties of the workpiece, the wheels and the workrest combined with the geometric relationship of their profiles are utilized to calculate the interaction between them, including the three forces along the axes and the three moments about the axes.

Wear Mechanisms in Ceramic Machining

1994 ◽  
Vol 47 (6S) ◽  
pp. S204-S208 ◽  
Author(s):  
T. N. Farris ◽  
S. Chandrasekar
Keyword(s):  
Wear Mechanisms ◽  
Material Removal ◽  
Abrasive Particle ◽  
Mechanical Action ◽  
Grinding Wheel ◽  
Relative Role ◽  
Ceramic Surface ◽  
Machining Processes ◽  
Tribochemical Reaction ◽  
Removal Process

Ceramic materials are finished primarily by abrasive machining processes such as grinding, lapping, and polishing. In grinding, the abrasives typically are bonded in a grinding wheel and brought into contact with the ceramic surface at relatively high sliding speeds. In lapping and polishing, the ceramic is pressed against a polishing block with the abrasives suspended in between them in the form of a slurry. The material removal process, here, resembles three body wear. In all of these processes, the mechanical action of the abrasive can be thought of as the repeated application of relatively sharp sliding indenters to the ceramic surface. Under these conditions, a small number of mechanisms dominate the material removal process. These are brittle fracture due to crack systems oriented both parallel (lateral) and perpendicular (radial/median) to the free surface, ductile cutting with the formation of thin ribbon-like chips, and chemically assisted wear in the presence of a reactant that is enhanced by the mechanical action (tribochemical reaction). The relative role of each of these mechanisms in a particular finishing process can be related to the load applied to an abrasive particle, the sliding speed of the particle, and the presence of a chemical reactant. These wear mechanisms also cause damage to the near ceramic surface in the form of microcracking, residual stress, plastic deformation, and surface roughness which together determine the strength and performance of the finished component. A complete understanding of the wear mechanisms leading to material removal would allow for the design of efficient machining processes for producing ceramic surfaces of high quality.

scholarly journals Research Method to Calculate Cutting Force when Longitudinal Feed Centerless Grinding

2019 ◽  
Vol 4 (10) ◽  
pp. 9-12
Author(s):  
Do Duc Trung ◽  
Nguyen Hong Son ◽  
Le Hong Ky ◽  
Le Hoang Anh
Keyword(s):  
Cutting Force ◽  
Translational Motion ◽  
Development Direction ◽  
Cutting Force Components ◽  
Centerless Grinding ◽  
Force Components ◽  
Rotation Motion ◽  
Control Wheel ◽  
And Control ◽  
The Relationship

The paper presents the results of analyzing the relationship between cutting force components and the force components exerting on the workrest blade, the ratio of slip - acceleration of the rotation motion between the part and control wheel, translational motion acceleration of the part along the axial axis when longitudinal feed centerless grinding. From that, the method of calculating cutting force components is calculated by measuring the force components exerting on the workrest blade, the ratio of slip, cceleration of the rotation motion between the part with control wheel, translational motion acceleration of the part along the axial axis. On that basis, this research also provides orientation for the construction of a system to measure the force, acceleration, velocity components, ... Then the development direction for the next research is also mentioned in the article.

Evaluation of the Possibilities of Processing High-Alloy Corrosion-Resistant Steels during Grinding Operations

2021 ◽  
Vol 1037 ◽  
pp. 603-613
Author(s):  
Andrey M. Romanenko ◽  
Dmitry B. Shatko ◽  
Andrey A. Nepogozhev ◽  
Pavel A. Strelnikov
Keyword(s):  
Depth Of Cut ◽  
Grinding Wheel ◽  
High Alloy ◽  
Corrosion Resistant ◽  
Temperature Changes ◽  
Steel Processing ◽  
Cutting Zone ◽  
Centerless Grinding ◽  
Control Wheel ◽  
Grinding Operations

The issues of processing high-alloy corrosion-resistant steels by the method of centerless cylindrical grinding are considered in the article. Experimental data on changes in the parameters of roughness and hardness of a workpiece depending on the depth of cut, the speed and the design features of a control wheel are presented. The change in the microhardness of a part depending on the depth of cut is analyzed. Much attention is paid to the study of thermal stress of the grinding process. Images of temperature changes in the cutting zone depending on the grinding wheel characteristics are shown. Conclusions in the form of practical recommendations for improving high-alloy steel processing by the method of centerless grinding are formulated on the basis of the results obtained.

A dynamic filtering obstacle detection method based on ultrasonic array

2016 ◽  
Vol 14 (04) ◽  
pp. 1650030
Author(s):  
Huihai Cui ◽  
Daxue Liu ◽  
Yan Li ◽  
Hangen He
Keyword(s):  
Detection Method ◽  
Detection System ◽  
Obstacle Detection ◽  
Filtering Method ◽  
Field Environment ◽  
Ultrasonic Array ◽  
Dynamic Filtering ◽  
Geometric Relationship ◽  
And Control ◽  
Relationship Of

In research on the navigation and control of an Autonomous Land Vehicle (ALV), the ultrasonic obstacle detection system plays an important role extending the environment cognition capability of the ALV. With a goal of improving the accuracy of ultrasonic obstacle detection, a dynamic data filtering method based on ultrasonic array is presented. The sonar return data is first processed through static filtering according to the geometric relationship of the ultrasonic array. Then, dynamic filtering is executed using the orientation and trajectory information of the vehicle. The dynamic filtering method is compared to the traditional ultrasonic obstacle detection method, which is the static filtering method in a typical field environment. The experiment result demonstrates the validity of the method for solving the fake data problem, and the accuracy of obstacle detection is improved.

ACCESS TO AND CONTROL OVER LAND AS GENDERED: CONTEXTUALIZING WOMEN’S ACCESS AND OWNERSHIP RIGHTS OF LAND IN RURAL GHANA

2016 ◽  
Vol 45 (2) ◽  
pp. 28-48 ◽  
Author(s):  
Isaac Dery
Keyword(s):  
Thematic Analysis ◽  
Rural Women ◽  
Rural Poor ◽  
Rural Ghana ◽  
Secure Access ◽  
Key Factor ◽  
Access Rights ◽  
Ownership Rights ◽  
And Control ◽  
Relationship Of

Women’s access to and control over productive resources, including land, has increasingly been recognized in global discussions as a key factor in reducing poverty, ensuring food security and promoting gender equality. Indeed, this argument has been widely accepted by both feminists and development theorists since the 1980s. Based on qualitative research with 50 purposively selected men and women, this study explored the complexity of women’s access to and control over land within a specific relationship of contestations, negotiations, and manipulations with men. Data were analyzed using thematic analysis. While theoretically, participants showed that women’s [secure] access to and control over land has beneficial consequences to women themselves, households and the community at large, in principle, women's access and control status was premised in the traditional framework which largely deprives women, equal access and/or control over the land. The study indicates that even though land is the most revered resource and indeed, the dominant source of income for the rural poor, especially women, gender-erected discrimination and exclusion lie at the heart of many rural women in gaining access to land. This study argues that women's weak access rights and control over land continue to perpetuate the feminization of gender inequality–while men were reported to possess primary access and control over land as the heads of households, women were argued to have secondary rights due to their ‘stranger statuses’ in their husbands’ families. Overall, the degree of access to land among women was reported to be situated within two broad contexts–marriage and inheritance.

scholarly journals Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Service Life ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

Development of a Ring Permeability Test System

2010 ◽  
Vol 136 ◽  
pp. 153-157
Author(s):  
Yu Hong Du ◽  
Xiu Ming Jiang ◽  
Xiu Ren Li
Keyword(s):  
Control System ◽  
Control Method ◽  
Dynamic Performance ◽  
Experimental Tests ◽  
Measuring Method ◽  
Test System ◽  
Fluid Theory ◽  
And Control ◽  
Relationship Of ◽  
The Mathematical Model

To solve the problem of detecting the permeability of the textile machinery, a dedicated test system has been developed based on the pressure difference measuring method. The established system has a number of advantages including simple, fast and accurate. The mathematical model of influencing factors for permeability is derived based on fluid theory, and the relationship of these parameters is achieved. Further investigations are directed towards the inherent characteristics of the control system. Based on the established model and measuring features, an information fusion based clustering control system is proposed to implement the measurement. Using this mechanical structure, a PID control system and a cluster control system have been developed. Simulation and experimental tests are carried out to examine the performance of the established system. It is noted that the clustering method has a high dynamic performance and control accuracy. This cluster fusion control method has been successfully utilized in powder metallurgy collar permeability testing.

Development of a New Plate Polishing Technique with an Instantaneous Tiny-Grinding Wheel Cluster Based on Magnetorheological Effect

2008 ◽  
Vol 53-54 ◽  
pp. 155-160 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Ai Jun Tang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Abrasive Particles ◽  
Magnetorheological Effect ◽  
Material Removal Model ◽  
Mr Effect ◽  
Removal Model

A new plate polishing technique with an instantaneous tiny-grinding wheel cluster based on the magnetorheological (MR) effect is presented in this paper, and some experiments were conducted to prove its effectiveness and applicability. Under certain experimental condition, the material removal rate was improved by a factor of 20.84% as compared with the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece was not obviously increased. Furthermore, the composite of the MR fluid was optimized to obtain the best polishing performance. On the basis of the experimental results, the material removal model of the new plate polishing technique was presented.

Parametric Study of Micro Machining Three Dimensional Microstructure with the Tiny-Grinding Wheel Based on the EMR Effect

2010 ◽  
Vol 447-448 ◽  
pp. 193-197
Author(s):  
Wei Qiang Gao ◽  
Qiu Sheng Yan ◽  
Yi Liu ◽  
Jia Bin Lu ◽  
Ling Ye Kong
Keyword(s):  
Magnetic Field ◽  
Material Removal Rate ◽  
Feed Rate ◽  
Material Removal ◽  
Rotation Speed ◽  
Optical Glass ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Machining Time ◽  
Fluctuation Phenomenon

Electro-magneto-rheological (EMR) fluids, which exhibit Newtonian behavior in the absence of a magnetic field, are abruptly transformed within milliseconds into a Bingham plastic under an applied magnetic field, called the EMR effect. Based on this effect, the particle-dispersed EMR fluid is used as a special instantaneous bond to cohere abrasive particles and magnetic particles together so as to form a dynamical, flexible tiny-grinding wheel to machine micro-groove on the surface of optical glass. Experiments were conducted to reveal the effects of process parameters, such as the feed rate of the horizontal worktable, feeding of the Z axis, machining time and machining gap, on material removal rate of glass. The results indicate that the feed rate of the worktable at horizontal direction has less effect on material removal rate, which shows a fluctuation phenomenon within a certain range. The feed rate of the Z axis directly influences the machining gap and leads to a remarkable change on material removal rate. Larger material removal rate can be obtained when the feeding frequency of Z direction is one time per processing. With the increase of rotation speed of the tool, material removal rate increases firstly and decreases afterwards, and it gets the maximum value with the rotation speed of 4800 rev/min. The machining time is directly proportional to material removal amount, but inversely proportional to material removal rate. Furthermore, material removal rate decreases with the increase of the machining gap between the tool and the workpiece. On the basis of above, the machining mode with the tiny-grinding wheel based on the EMR effect is presented.

Computer-Aided Simulation of Dressing Using Diamond Rotary Dresser and Visualization of Dressing Process

2014 ◽  
Vol 1017 ◽  
pp. 592-597 ◽  
Author(s):  
Akihiko Kubo ◽  
A.M.M. Sharif Ullah ◽  
Jun’ichi Tamaki
Keyword(s):  
Solid Body ◽  
Surface Profile ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Wheel Surface ◽  
Contour Map ◽  
Removal Process ◽  
Computer Aided ◽  
Actual Depth

The surface of a grinding wheel dressed by a diamond rotary dresser was generated by computer-aided simulation for the case of multipass dressing on the assumption that the grinding wheel is a homogeneous solid body and the dressing trajectories of the diamond grits are perfectly copied on the grinding wheel surface. The dressing process was visualized as a contour map of the dressed surface profile and the effects of the dressing strategy, i.e., down-cut dressing or up-cut dressing, on the grinding wheel removal process were investigated. It was found that the diamond grits remain the residual depth of cut on the surface of the grinding wheel, resulting in an actual depth of cut larger than that given by the rotary dresser.

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