Showing 19 results for Cutting Force
Volume 8, Issue 3 (7-2006)
Abstract
In order to help in the engineering design of rice harvesting machines, there is a need to have exact information concerning the physical and mechanical properties of rice stems. The cutting force for rice stems, therefore, was measured by designing and fabricating a static and dynamic shear test apparatus. The effects of moisture levels and the cross-sectional area of stem as well as the variety, blade bevel angle, blade type and cutting speed on shearing strength have been evaluated. The results indicated that the cutting force increased with an increase in the cross-sectional area and decreased with an increase in moisture content. The static and dynamic shearing strength was different among the varieties. The maximum and minimum shearing strengths were related to the varieties Khazar and Hashemi, with an average of 1629 and 1429 kPa for static test and values of 187.4 and 144 kPa for the dynamic test, respectively. The shearing strength decreased from 234.4 kPa to 137.4 Kpa with an increase in blade cutting speed from 0.6 to 1.5 m/s. Blade bevel angle and blade type had no significant effect on the shearing strength of rice stem.
Mohammad Mahdi Jalili, Hojjatollah Tavari,
Volume 14, Issue 4 (7-2014)
Abstract
A new 3-D nonlinear model of chatter vibration in turning process is presented in this paper. Workpiece and cutting tool are modeled as rotational shaft and cantilever beam, respectively which are excited by cutting forces. Equations of motion of workpiece are derived using Hamilton’s principal. Also, Timoshenko beam theory is used to simulate tool’s vibration. Then π-Buckingham theory is used to extract dimensionless equations of motion for transverse and torsional vibrations of workpiece and transverse and longitudinal vibrations of cutting tool. Using the mode summation method, a numerical solution is presented for this nonlinear problem. Effect of cutting parameters such as longitudinal cutting position, cutting width, cutting depth and radius of workpiece for machining with and without tailstock are investigated. Using these results turning velocity intervals for stable and unstable cuts are determined. Simulation results show that using tailstock in turning process for machining near the end of the workpiece increases process stability. Also in the case of using tailstock, machining near the end of the workpiece is more stable than the machining in the middle region of the workpiece.
Mohammad Mahdi Abootorabi Zarchi, Amir Abdullah, Mohammad Reza Razfar,
Volume 14, Issue 9 (12-2014)
Abstract
Calculation the cutting force in machining processes is of great importance. In this paper, undeformed chip thickness in one-dimensional ultrasonic vibration assisted milling is calculated and then, a model for determining the cutting force in this process is presented. Analytical relations show that in ultrasonic assisted milling (UAM), the maximum cutting force is greater than in conventional milling (CM), but the average cutting force is decreased. To verify the proposed relations, with the aid of a particular experimental setup, one-dimensional vibration in feed direction is applied to workpiece and cutting force in CM and UAM is measured experimentally. Greater maximum cutting force in UAM and decrease of average cutting force in UAM compared to CM is observed experimentally as well. Comparison of average values of cutting force shows that the analytical relations for predicting the cutting force have 16% average error in CM and 40% average error in UAM. Given that the analytical calculation of undeformed chip thickness and cutting force in UAM and also comparison of experimental forces with the modeled ones has been done in this paper for the first time, the accuracy of proposed relations are acceptable.
Masoud Farahnakian, Mohammad Reza Razfar, Farid Reza Biglari,
Volume 15, Issue 1 (3-2015)
Abstract
Plasma assisted machining (PAM) is a method to improve machinability of hard turning. The process of plasma assisted machining for turning applications utilizes a high-temperature plasma arc to provide a controlled source of localized heat, which softens only that small portion of the work material removed by the cutting tool. The goal of this study is to present a methodology for determination cutting force during plasma enhanced turning of hardened steel AISI 4140. In this regard, a finite differential model was made to estimate the uncut chip temperature under different plasma currents, cutting speeds and feeds during PAM. A mechanistic model developed to estimate cutting force under different PAM conditions by considering shear stresses in the primary, secondary shear zones and force on the tool edge. The proposed model was calibrated with experimental hard turning data, and further validated over practical PAM conditions. Mean errors of predicted values and experimental data is lower than 10 percent. It is shown that PAM can decrease main cutting force in comparison to convectional to 40 percent in turning of hardened steel at high levels of uncut chip temperature due to softening the material.
Mohammad Mahdi Abootorabi Zarchi, Mohammad Reza Razfar, Amir Abdullah,
Volume 15, Issue 5 (7-2015)
Abstract
Reduction of cutting force in a machining process offers several advantages including increase in tool life, and improvement in the quality of the machined surface. One the new techniques for reducing cutting force relates to ultrasonic vibration assisted machining. In the present paper, one-dimensional ultrasonic vibration-assisted side milling process of Al7022 aluminum alloy has been studied. In order to investigate the effect of cutting speed, feed rate, radial depth of cut, and vibration amplitude on three cutting force components and their resultant, a special experimental setup has been designed and established which applies one dimensional ultrasonic vibration to work piece. Applying the ultrasonic vibrations on milling process, affects mostly on feed component of cutting force which is unidirectional with the work piece vibration, and decreases it by 33.5% in average. Decrease in cutting speed and increase in vibration amplitude, results to increase the separation of tool and work piece from each other in a portion of each vibration cycle, and larger decrease of the feed force. The average decrease of the resultant cutting force in ultrasonic-assisted milling process is 10.8%.
Hamed Rezaei, Mohamad Hosein Sadeghi,
Volume 16, Issue 12 (2-2017)
Abstract
Nowadays, emerging more advanced computer systems made it possible to simulate and model complex problems even with higher accuracy. Regarding lower time and cost, the use of simulations instead of physical experiments is increasingly considered as an alternative method in the analysis and optimization of process performance. The importance of such methods becomes more significant when talking about micro-processes, since there are lots of difficulties in experimental measurements as a results of scaling problems by scaling down from macro to micro. In this study, a 3D model is developed using Deform-3D software for prediction of micromilling process behavior. Effects of cutting parameters on such characteristics as cutting forces, temperature distribution and tool wear are investigated. To check the validity of the model, force results of simulation are compared with the measured ones. A high level of correlation exists between the obtained simulation and measured results which shows that the 3D developed model has good capability to predict process behavior.
Mohammad Sadegh Heydarzadeh, Seyed Mehdi Rezaei, Noor Azizi Bin Mardi, Ali Kamali,
Volume 17, Issue 6 (8-2017)
Abstract
Micro-milling is prominent among other micro-manufacturing processes due to their abilities in manufacturing of 3D features, high material removal rates and high precision. One of the most important challenges of this process is tool deflections which contribute even up to 90% of dimensional errors of the finished product. This paper addresses a novel method to estimate micro-milling tool deflections applicable in micro-milling machines equipped with linear motors. In this method, position feedbacks and inputs to the amplifiers are used to real-time estimation of cutting forces by applying Kalman filter. Outputs of the estimator include a resultant of all disturbing forces in servo control loop of the motors. Therefore, cutting forces need to be compensated for other disturbing forces that are mostly friction and force ripples in linear motors. To compensate them, neural networks were used. A neural network with a hidden layer and 16 nodes inside, and with two time-delayed lined (TDL) could well model friction and force ripples. Results showed that the proposed tool deflection method is able to estimate 22% of micro-milling tool deflections.
S.a. Sajjady, S. Amini,
Volume 19, Issue 8 (8-2019)
Abstract
Since the invention of ultrasonic vibration assisted turning, this process has been widely considered and investigated. The reason for this consideration is the unique features of this process, which include reducing machining forces, reducing wear, and friction, increasing the tool life, creating periodic cutting conditions, increasing the machinability of difficult-to-cut material, increasing the surface quality, creating a hierarchical structure (micro-nano textures) on the surface and so on. Different methods have hitherto been used to apply ultrasonic vibration to the tip of the tool during the turning process. In this research, a unique horn has been designed and constructed to convert linear vibrations of piezoelectrics to three-dimensional vibrations (longitudinal vibrations along the z axis, bending vibrations around the x axis, and bending vibrations around the y axis). The advantage of this ultrasonic machining tool compared with other similar tools is that in most other tools, it is only possible to apply one-dimensional (linear) and two-dimensional (elliptical) vibrations, while this tool can create three-dimensional vibrations. Additionally, since the nature of the designed horn can lead to the creation of three-dimensional vibrations, there is no need for piezoelectric half-rings (which are stimulated by 180 phase difference) to create bending vibrations around the x and y axes. The reduction of costs as well as simplicity of applying three-dimensional vibrations in this new method can play an important role in industrializing the process of three-dimensional ultrasonic vibration assisted turning.
A.m. Rashidi, H. Ramazani,
Volume 19, Issue 11 (11-2019)
Abstract
In this research, the effects of partially austenitising time on the machinability of spheroidal graphite (SG) cast iron with ferrite-martensite dual matrix structure (DMS) were investigated to optimize its machinability. Specimens with non-alloy ferrite matrix structure were prepared by the casting process. Then the specimens were austenitized at temperatures of 900 oC at various times (5 to 25 min) and subsequently quenched into the water to produce DMS with martensite volume fractions. The Brinell hardness test method was used to determine the hardness of specimens. The machinability of the workpieces with ferrite and dual structures were investigated by measuring the surface roughness and primary cutting force. According to the results, the Johnson-Avram kinetic model was valid for correlation between the martensite volume fraction and autenitising time. The surface roughness was increased and the cutting force was decreased with increasing austentising time to 12 min, and consequently, with increase the hardness to 168 BHN. The heating at 900 oC for 12 min resulted in 16-20% and 15-23% improvement on the cutting force and specific cutting power, respectively, when compared to as-cast specimen, while the surface quality remained at the same level. The cutting force was correlated with feed rate as a power model with exponents of 0.77 and 0.73 for DMS (with 30% martensite) and ferritic as-cast samples, respectively.
M. Qasemi, M. Sheikhi, M. Zolfaghari, V. Tahmasbi,
Volume 20, Issue 4 (4-2020)
Abstract
Cortical bone milling is used in orthopedic surgeries such as knee replacement, otological, spinal cord, and hip replacement. The cutting forces created by the cutting tool during cortical bone milling in order to control the wear of the tool as well as applying allowable force to the bone to prevent fracture should be controlled. In this paper, the effective parameters in the bone milling including cutting speed, feed rate, cutting depth and tool diameter has been investigated using the response surface method in order to predict the cutting forces. In this method, a second-order linear regression equation can be presented in order to predict the behavior of the bone milling process precisely. Also, Sobel's sensitivity analysis method was used to study the effect of input parameters on the behavior of cutting force. In this research, the behavior of different input parameters and the effect of their interactions on the machining force has been evaluated and analyzed. The components of cutting force were measured and investigated in three directions of feed, perpendicular to the feed and perpendicular to the bone surface. The results show that the mathematical model governing the problem has a proper function within the range of the defined parameters and it can provide a good prediction of force behavior. The minimum cutting force can be achieved in a rotational speed of 1500 rpm, feed of 12 mm/min, tool diameter of 2 mm, and cutting depth of 0.2 mm. Also, about the sensitivity of the force behavior based on the input parameters variation in the range of experiments, the greatest effect was related to the cutting depth with 36.3% of the effect, and feed rate with 28.4% of the effect, the diameter of the tool with 27.5% of the effect and the rotational speed with 7.8% of the effect.
Hamid Reza Esrafili, Hossein Amirabadi, Javad Akbari, Farshid Jafarian,
Volume 22, Issue 10 (10-2022)
Abstract
Waspaloy is a type of nickel-based superalloy that is mainly used in aircraft turbine parts, compressor disks, shafts, and turbine parts. Waspaloy, like many nickel-base superalloys, is difficult to a machine at room temperature (conventional machining). In this paperwork, the cutting force and temperature created in the cutting area of the workpiece by changing different cutting parameters: cutting speed, feed rate, and constant depth of cut, in the dry oblique turning process of Waspaloy investigated. The hardness of the tested workpiece was 382±3 Vickers. In order to investigate the cutting force and the temperature of the cutting area, a full factorial experiment design without repetition was used, and a regression model of the influencing factors was presented to estimate the cutting force. Specifically, by an increase in the feed rate from 14 to 42 (mm/min), the most cutting force change occurred when the cutting speed was 1200 (rpm) and the depth of cut was 0.3 (mm). Moreover, except in test 6, the machining temperature increased with the rise of cutting speed and feed rate in all experiments.
Saeid Movahedian , Mohammad Javad Nategh,
Volume 22, Issue 10 (10-2022)
Abstract
In this article, the effect of optimal selection of vibration and cutting parameters on cutting forces in the machining process with ultrasonic vibration assistance has been investigated and the results have been compared in two modes of conventional machining and of ultrasonic vibration assisted machining. In the investigation of the effect of ultrasonic vibration assistance on the machining process, analyzes have been carried out in different cutting speeds, and the effect of changing the cutting speed in relation to the tool's oscillation speed has been investigated. Finite element modeling and simulation has been done with DEFORM finite element software. The results show that the application of ultrasonic vibration in the machining process leads to the reduction of tangential and axial cutting and the reduction of heat resulting from the cutting process. By examining the results, it was found that in the machining process with ultrasonic vibration assistance, when the cutting speed is at least 30% lower than the vibration speed of the tool tip, the process has a favorable efficiency, and the favorable effects of applying ultrasonic vibration on the process include reducing shear forces, reducing the heat generated From cutting, reducing the friction coefficient between the tool and the workpiece, helping to improve the chip flow, etc.
Vahid Tahmasbi, Sepehr Aeinehbandy, Mohammad Hafez Baghi, Amin Sousanabadi Farahani,
Volume 23, Issue 8 (8-2023)
Abstract
Advances in many engineering fields depend on materials with appropriate properties. The use of metal-matrix composites is rapidly growing as a suitable alternative to conventional materials due to their strength-to-weight ratio, resistance to wear and creep, etc. Machining of metal-based composites is a difficult task due to the presence of very abrasive reinforcing particles in its based metal. Therefore, it is necessary to investigate the factors affecting these materials. In this research, a methodical study has been conducted to investigate the effect of the parameters of spindle speed, feed rate, depth of cut and the percentage of reinforcing particles on the behavior of cutting force and tool wear using experimental design methods, modeling and statistical sensitivity analysis methods. . Detailed analysis of behaviors has been done by providing statistical regression equations and optimization by Deringer's method and E-Fast-Sensitivity Analysis. According to the obtained results, the cutting depth had the greatest effect on the machining force. Also, cutting speed with 77%, advance rate with 9% percent and cutting depth and weight percent of reinforcing particles with 7% percent are other parameters affecting tool wear in the milling process of this composite.
Moein Taheri , Ahmad Reza Arabzadeh ,
Volume 23, Issue 10 (10-2023)
Abstract
Today, the machining and milling of composites is of great importance; Because composites are used in various sectors and have found great efficiency in various industries. Considering this, in this article, in order to save the cost of milling composites, the effectiveness of various parameters that affect the cutting force and tool wear, including spindle speed (rpm), feed rate (mm/rev), cutting depth (mm) and percentage of sic, has been discussed; To minimize tool wear and cutting force by creating optimal conditions. Performing a sensitivity analysis according to the regression equations of cutting force and tool wear has shown that spindle speed with 63% and the percentage of composite silicon carbide with 22% have the greatest effect on tool wear and depth of cut with 47% and advance with 23% have the greatest effect on cutting force.
Saeid Amini , Reza Saebirad ,
Volume 23, Issue 10 (10-2023)
Abstract
Turn-milling is a new process that uses, turning and milling operations together, so that the tool and the work piece rotate simultaneously, for this reason, it has a wide ability in machining curved and complex surfaces. The Main subject of this research is Conducting research on the effect of changes in machining parameters, including work piece rotational speed, tool rotational speed and feed rate, on cutting parameters such as cutting force, cutting pressure, and surface finish parameters. The order and the number of experiments is designed based on the full factorial method. Experiments for each of the mentioned parameters were performed at three levels, which includes 27 tests in total. The results were analyzed with the help of Minitab software. The mentioned process was performed with a φ6 diameter end mill on a steel work piece 1.7225. As a result, increasing feed rate by three times increases the machining force by about two times and reduces the cutting pressure by about 27%, Also, the surface finish quality parameters R a and R z increased by 74% and 61%, respectively. The upward or downward trend of cutting forces, cutting pressure and the surface finish quality did not occur with the increase in the rotational speed of the work piece and the rotational speed of the tool, in fact, an extremum range was achieved in the increasing trend of the mentioned speeds. So that the minimum resultant force and also the cutting pressure were observed in the range of rotational speed of 950rpm of the tool and 300rpm of the work piece.
Amin Sousanabadi Farahani , Mahdi Modabbarifar ,
Volume 23, Issue 10 (10-2023)
Abstract
The properties of metal-based composites, such as their high strength-to-weight ratio and good resistance to wear and fatigue, have caused a significant growth in their use in the aerospace, automotive, and aircraft industries. Magnesium-based composites have particularly attracted the attention of researchers in various fields, especially aerospace scientists, due to their lower density than other metal-based composite alloys such as titanium and aluminum. However, due to the presence of very abrasive reinforcing material in these materials, machining them is difficult and presents numerous challenges. Therefore, it to study the machining process of these is necessary composites and to examine the effect of the main turning parameters such as cutting speed, feed rate, and depth of cut on machining forces and surface roughness. Sobol's sensitivity analysis method was used for this purpose. Using this method, it was determined that the feed rate, cutting depth, and cutting speed have the greatest effect on the machining forces, respectively. Additionally, the feed rate has a greater effect on the surface roughness than the cutting depth and cutting speed. As the feed rate increases, the surface roughness and cutting forces increase.
Mohammad Yazdani Khameneh, Mohsen Sadr, Amir Rasti, Mohammad Hossein Sadeghi,
Volume 24, Issue 1 (12-2023)
Abstract
The effect of texturing the tool rake surface on the surface quality in hard turning of 1191/1 steel with a surface hardness of 45 HRC was studied in this research. The pattern parameters including, cavity diameter, pitch, and depth, as well as the pattern distance from the main cutting edge were changed in 3 levels, assuming the cutting tool with regular cavity texture. Nine tests were designed using the Taguchi DOE and conducted in dry and lubricated conditions with 2 repeats. Machining forces during the tests and surface roughness of the machined workpieces were measured in machining under lubricated and dry conditions. The results showed that in turning with a textured tool under lubrication, changing the parameters of the texture pitch and the distance from the cutting edge increased the surface roughness of the workpiece by 57.6% and 39.2%, respectively. This is while the increase in the diameter of the tissue cavity, due to the reduction of the contact area in the tool-chips interface and better lubrication near the cutting region, improved the surface roughness up to 40.7%. The cavities depth of also did not have a significant effect on improving lubrication and reducing the roughness of the final surface. In dry turning, increasing the cavities diameter in texture and decreasing the pattern pitch, reduced the surface roughness by 10.6% and 29%, respectively. Examining the SEM images also indicated the production of the workpiece surface with smoothed texture when turning using optimized textured tool.
Hamid Reza Esrafili, Hosien Amirabadi, Javad Akbari, Farshid Jafarian,
Volume 24, Issue 6 (5-2024)
Abstract
The conventional material removal processes have always run into difficulties in machining hard materials, and nickel-based superalloys are no exception. The inherent properties of these materials usually lead to high tool wear rates and low surface integrity. These concerns justify the need for combining conventional material removal processes with advanced technologies. Laser Assisted Machining is one such process by which, through localized softening of work material prior to the cutting operation, a more efficient material removal process can be realized compared with what can be done by conventional machining. This work studies the effect of machining parameters such as constant Rotational speed at 400 RPM, feed rates of 0.035, 0.07, 0.105 mm/rev, and cutting depths of 0.3, 0.6, and 0.9 mm on variation of cutting force, chip temperature, surface roughness, and microhardness in variation of the workpiece surface. The process is a Laser Assisted Turning (LAT) process compared to conventional Turning (CT) by analyzing the parameters for a Waspaloy. A fiber laser with constant power output of 500 W was used to irradiate the tool material. The angle of contact of the beam with the tip of the tool was fixed at 60°. The workpiece's hardness was 385 ± 10 Vickers initially and had a diameter of 25 mm. It has been revealed that the application of LAT decreases the cutting force up to 16% compared to CT. The workpiece surfaces produced by LAT had higher chip temperatures than CT and were of 42% better quality in terms of surface roughness. In the LAT process, the difference in microhardness values at different points on the workpiece surface was within a much smaller range than in the CT process. The results showed that as the scanning speed of the laser increased on the surface of the workpiece, the thickness of the laser heat-affected zone below the surface of the workpiece decreased.
Mohsen Sabzalipour, Ali Mohammad Rashidi,
Volume 24, Issue 8 (7-2024)
Abstract
The main goal of present work is to identify the appropriate austenitising category to achieve the austempered ductile irons with dual matrix structure having the best possible machinability. In this regard, specimens of low-alloyed ferritic spheroidal graphite cast iron were prepared by casting process. In order to obtain a mixed ferrite-austenite structures having different volume fraction of austenite phase, samples were subjected to one of two processes: a) partial austenitising at 870 oC for various times (5 to 60 min) or b) intercritical austenitising at various temperatures (750, 765, 780 and 800 oC) for 60 minutes. After that they were austempered in molten salt at a temperature of 350 oC for one hour. During turning with a lathe equipped with a force dynamometer, the cutting forces of the workpieces were measured as a general adopted criterion for machinability investigation. According to the obtained results, with the increase of partial austenitising time or intercritical austenitising temperature, the volume fraction of the ausferrite phase increased, but the cutting force decreased initialy and then increased. For a certain percentage of the ausferrite phase, the turning of samples prepared with partial austenitising process was associated with lower cutting force, compared to the samples obtained by the intercritical austenitising process. In general, it can be concluded that the maximum machinability of dual matrix ductile iron austempered at 350 oC is achieved when the selected austenitising temperature and time results to creation dual matrix structure containing 39 ± 3 Vol% ausferrite phase
