scholarly journals A predictive model for the cutting force in wood machining developed using mechanical properties

BioResources ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. 2883-2894 ◽  
Author(s):  
Andrew Naylor ◽  
Phil Hackney ◽  
Noel Perera ◽  
Emil Clahr

In this study a number of work-piece variations were evaluated whilst limiting the cutting conditions. Eight wood species controlled at four moisture levels were machined along and across the wood grain. The tool used during cutting was designed to resemble a rip saw tooth with zero rake angle and narrow edge width. Each work-piece variation machined in the cutting tests was subjected to mechanical tests that evaluated bending properties across the grain and shear properties along the grain. The regression model establishes a relationship between the bending properties for cutting forces across the grain, as well as shear properties for cutting forces along the grain. F and R² values show that the elastic properties of the wood in bending and shear have less influence on the cutting forces when compared to the strength and toughness. Additionally, density is seen to have less influence on the cutting force along the grain. This is explained by the tool passing through an unquantifiable proportion of early and latewood fibers from the annual growth rings. Cutting across the grain, the tool is forced to machine through approximately the same proportion of earlywood and latewood fibres.

2015 ◽  
Vol 799-800 ◽  
pp. 366-371 ◽  
Author(s):  
Deuanphan Chanthana ◽  
Somkiat Tangjitsitcharoen

The roundness is one of the most important criteria to accept the mechanical parts in the CNC turning process. The relations of the roundness, the cutting conditions and the cutting forces in CNC turning is hence studied in this research. The dynamometer is installed on the turret of the CNC turning machine to measure the in-process cutting force signals. The cutting parameters are investigated to analyze the effects of them on the roundness which are the cutting speed, the feed rate, the depth of cut, the tool nose radius and the rake angle. The experimentally obtained results showed that the better roundness is obtained with an increase in cutting speed, tool nose radius and rake angle. The relation between the cutting parameters and the roundness can be explained by the in-process cutting forces. It is understood that the roundness can be monitored by using the in-process cutting forces.


2012 ◽  
Vol 510 ◽  
pp. 50-53
Author(s):  
Chun Lei Li

Sources and measurement of cutting forces are studied to establish the steady-state cutting force prediction model. Modeling of work piece machining error is analyzed, a simplified process coordinate system is established, and the mathematical solving model of machining error within the work piece is given. The cutting force due to work piece bending deformation is studied, a work piece deformation factor error model is established based on steady-state cutting force and the prediction simulation of cutting forces and machining error is achieved.


2011 ◽  
Vol 223 ◽  
pp. 85-92 ◽  
Author(s):  
Balázs Tukora ◽  
Tibor Szalay

In this paper a new method for instantaneous cutting force prediction is presented, in case of sculptured surface milling. The method is executed in a highly parallel manner by the general purpose graphics processing unit (GPGPU). As opposed to the accustomed way, the geometric information of the work piece-cutter touching area is gained directly from the multi-dexel representation of the work-piece, which lets us compute the forces in real-time. Furthermore a new procedure is introduced for the determination of the cutting force coefficients on the basis of measured instantaneous or average orthogonal cutting forces. This method can determine the shear and ploughing coefficients even while the cutting geometry is continuously altering, e.g. in the course of multi-axis machining. In this way the cutting forces can be predicted during the machining process without a priori knowledge of the coefficients. The proposed methods are detailed and verified in case of ball-end milling, but the model also enables the applying of general-end cutters.


2020 ◽  
Vol 15 (4) ◽  
Author(s):  
Krishna Kumar M ◽  
Sangaravadivel P

The measurement of cutting forces in metal cutting is essential to estimate the power requirements, to design the cutting tool and to analyze machining process for different work and tool material combination. Although cutting forces can be measured by different methods, the measurement of cutting forces by a suitable dynamometer is widely used in industrial practice. Mechanical and strain gauge dynamometer are most widely used for measuring forces in metal cutting. The principle of all dynamometers is based on the measurement of deflections or strain produced from the dynamometer structure from the action of cutting force. In this project, a dynamometer is used to measure cutting force, feed force and radial force by using strain gauge accelerometer while turning different material in lathe. The dynamometer is a 500kg force 3- component system. As the tool comes in contact with the work piece the various forces developed are captured and transformed into numerical form system. In this project three forces of different materials such as aluminum, mild steel, brass, copper have been noted down. The forces on these materials with variation in speed and depth of cut are studied. Graphs are drawn on how these forces vary due to variation in speed.


2020 ◽  
Vol 14 (2) ◽  
pp. 253-259
Author(s):  
Abdallah Abdelkawy ◽  
Masahiko Yoshino ◽  
Yuki Nakagawa ◽  
◽  

The effects of negative rake angles on the ductile mode cutting of soda glass and sapphire were studied. In addition, the machining mechanism was studied using a groove-cutting model based on the orthogonal cutting theory. It was found that the specific cutting forces in ductile mode cutting increase on both the soda glass specimen and on the sapphire specimen when the rake angle of the tool becomes negative. The difference between the experimental data and theoretical data of the specific cutting forces becomes large when the tool has a high rake angle on the negative side. This is attributed to effects of the roundness of the edge, the effects of the roundness of the nose, and the plowing mechanism, which causes plastic flow of the work material to both sides of the groove. The specific cutting force of sapphire depends on the cutting direction against the crystal orientation. The specific cutting force of sapphire depends on the cutting direction in terms of the crystal orientation. The anisotropy of the cutting force of sapphire also depends on the rake angle of the tool.


2013 ◽  
Vol 765 ◽  
pp. 343-347 ◽  
Author(s):  
Yao Xi ◽  
Michael Bermingham ◽  
Gui Wang ◽  
Matthew Dargusch

The improvement of machinability during thermally assisted turning of Ti-6Al-4V alloy was investigated by finite element modelling. A 2D thermally assisted turning model was developed and validated by comparing the simulation results with experimental results. Detailed analyses were carried out on the simulations in terms of the influence of the initial work-piece temperature on cutting forces and chip formation in the TAM process. The predicted cutting forces showed a very good correlation to the experimental results, and both the simulation and experiments have proved that the initial work-piece temperature plays an important role in determining the cutting force, with increasing initial temperature reducing the cutting force.


Author(s):  
Sabri Ozturk

In this study, the effects of the rake angle on main cutting force (Fc), and thrust forces (Ft) was investigated. A new slip line model approach for modelling the orthogonal cutting process was proposed. This model was applied at negative rake angles from 0° to –60° and consists of three regions. The main forces were measured with a computer aided quick stop device. Variance Analysis (ANOVA) was utilized to analyze the effects of the cutting parameters on cutting and thrust forces accordingly. Multi-variable regression analysis was also employed to determine the correlations between the factors and the cutting forces. The cutting forces could be calculated by equation parameters which are the rake angle and the uncut chip thickness.


Author(s):  
Amir Masoud Tahvilian ◽  
Henri Champliaud ◽  
Zhaoheng Liu ◽  
Bruce Hazel

A flexible robotic grinding system has been used for in situ maintenance of large hydro turbine runners by Hydro-Quebec. Field trials for more than 20 years have proven the reliability and efficiency of the technology for hydropower equipment maintenance and repair. This portable robot named SCOMPI, is developed by IREQ, Research Institute of Hydro-Quebec and can perform high material removal rate grinding on hardly accessible areas of turbine runner blades. Due to the light weight and low rigidity of the robot, traditional position control of conventional grinding is not applicable in this process. Instead a hybrid force/position controller is employed to ensure the accuracy of the predefined material removal rate. Therefore, having a good force model for a specific removal rate is a prerequisite for controlling the grinding task. Understanding the grinding process as the cutting action of several single grits participating in the material removal process provides an insight to predict the needed forces. This paper presents an investigation of the effects of grits shape on cutting forces in single abrasive cutting mechanism during high removal rate grinding by SCOMPI robot. A three-dimensional finite element model is developed to simulate the chip formation process with different grit shapes. Thermal results from our previous study of temperature distribution in the contact zone for this special robotic grinding are imposed to the un-deformed chips. Then, Johnson-Cook plasticity model is employed to investigate effects of hardening and thermal softening of work piece material in cutting forces. It is also found that, rake angle and cutting edges of the grit can have significant effects on the cutting and normal forces.


2016 ◽  
Vol 836-837 ◽  
pp. 168-174 ◽  
Author(s):  
Ying Fei Ge ◽  
Hai Xiang Huan ◽  
Jiu Hua Xu

High-speed milling tests were performed on vol. (5%-8%) TiCp/TC4 composite in the speed range of 50-250 m/min using PCD tools to nvestigate the cutting temperature and the cutting forces. The results showed that radial depth of cut and cutting speed were the two significant influences that affected the cutting forces based on the Taguchi prediction. Increasing radial depth of cut and feed rate will increase the cutting force while increasing cutting speed will decrease the cutting force. Cutting force increased less than 5% when the reinforcement volume fraction in the composites increased from 0% to 8%. Radial depth of cut was the only significant influence factor on the cutting temperature. Cutting temperature increased with the increasing radial depth of cut, feed rate or cutting speed. The cutting temperature for the titanium composites was 40-90 °C higher than that for the TC4 matrix. However, the cutting temperature decreased by 4% when the reinforcement's volume fraction increased from 5% to 8%.


2006 ◽  
Vol 5-6 ◽  
pp. 367-374
Author(s):  
C. G. Dumitraş

Due to robotic deburring development, the research gains a new orientation and focused on the cutting forces and the chip control. The present paper will emphasize the main difference which occurs between the normal cutting process and the deburring process, the way it develops and the parameters which characterize this process. Also the dynamics of the process are considered. Based on a central composite design one determine a relation between the geometry of the tool, workpiece hardness and cutting force.


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