Cutting Force Measurement Research Articles

Cutting force measurement of electrical jigsaw by strain gauges

This paper describes a measuring method based on strain gauges for accurate specification of electric jigsaw's cutting force. The goal of the measurement is to provide an overall perspective about generated forces in a jigsaw's gearbox during a cutting period. The lifetime of the tool is affected by these forces primarily. This analysis is part of the research and development project aiming to develop a special linear magnetic brake for realizing automatic lifetime tests of electric jigsaws or similar handheld tools. The accurate specification of cutting force facilitates to define realistic test cycles during the automatic lifetime test. The accuracy and precision resulted by the well described cutting force characteristic and the possibility of automation provide new dimension for lifetime testing of the handheld tools with alternating movement.

Tensile mechanical properties of greenhouse cucumber cane

Abstract: To obtain the mechanical properties of greenhouse cucumber cane, tensile and shear properties of the greenhouse cucumber cane were studied by using computer-controlled electronic universal testing machine and homemade cutting test bench, respectively. Firstly, the root, middle and head of cucumber cane were subjected for tensile tests. The tensile stress-strain curves showed that the root of cumber cane presented the characteristics of plastic material, while the middle and head showed the characteristics of brittle material. The average tensile strength of root, middle and head of fresh cucumber cane were 7.35 MPa, 6.30 MPa and 4.68 MPa, respectively. The average elastic modulus of root of fresh cucumber cane was 280.58 MPa, which was much greater than the middle and head with average elastic modulus of 198.81 MPa and 137.22 MPa, respectively. A pendulum impact cutting test-rig and a cutting force measurement system composed of a cantilever weigh sensor, a high frequency DAQ card and motion control card were developed. The cutting mechanical property experiments of different parts of greenhouse cucumber cane were carried out, and the continuous curves of cutting force were measured. The single factor test for cross-sectional area, cutting speed, cutting tool type and manner were analyzed. The results indicated that the peak cutting force increased approximately linearly with the increasing of cutting sectional area, but decreased gradually with the increasing of cutting speed. In the same conditions, the cutting force could be reduced by using straight blade cutting tool and ramp cutting way. Through the multifactor interaction impact test of the cutting way, the blade type and the cutting speed, it was found that the corresponding F-value of the three factors were 21.316, 49.141 and 0.222, which suggests that the blade type is the most significant factor for the cutting force. Keywords: cucumber cane, mechanical properties, modulus of elasticity, tensile strength, cutting force DOI: 10.3965/j.ijabe.20160905.1725 Citation: Xu Y F, Zhang X L, Sun X J, Wang J Z, Liu J Z, Li Z G, et al. Tensile mechanical properties of greenhouse cucumber cane. Int J Agric & Biol Eng, 2016; 9(5): 1－8.

A novel machinability test for determining the cutting behaviour of iron-based, carbon-containing and copper-containing powder metallurgy steels (PMS)

Parts made by powder metallurgy generally do not require subsequent machining operations. However, further machining of these sintered parts cannot be avoided in case of special, complex geometries. The goal of the research discussed in this paper is to create an easy-to-use, time-efficient and cost-efficient method to describe the secondary machining properties of iron-based, copper-containing and carbon-containing powder metallurgy steels (PMSs) in terms of the energy indicators. In order to compare the machinability of PMSs with different compositions, a new test method was developed. Considering the high importance of the turning process in the manufacturing of PMS parts, a short axial grooving test was developed. Cutting force measurements were carried out where the characteristics of the measured signal referred to the machinability of the tested materials. This newly developed test can be carried out quickly, and it can successfully be applied to characterize the energetics of PMS machining. Based on the test results, appropriate alloying element percentages could be determined.

Active damping of machine tool vibrations and cutting force measurement with a magnetic actuator

This paper presents a novel multifunctional magnetic actuator, which not only damp the vibration of machine tools but also measure the cutting force in real time. The actuator is composed of four identical electromagnetic units which are linearized with a novel design strategy. The magnetic force can be delivered in two radial directions for active damping of the flexible structures in the machine tools. Cutting force is estimated from the armature displacement and the control current of the actuator. The performance of both active damping and cutting force measurement are demonstrated on a boring bar which is clamped to the turret of a CNC lathe. Experimental results show that the boring bar vibration is damped significantly with a velocity feedback controller, resulting in a higher chatter-free depth of cut, while the measured cutting force from the actuator agrees with the reference force quite well.

Microfabrication and Characterization of Tool Embedded Ni-Chrome Thin Film Micro-Sensors for Cutting Force Measurement

This paper investigated the fabrication and design of embedded Ni-chrome thin-film strain gauges as micro-sensors in tool holders to measure the cutting force in machining operations. A Ni-chrome thin film as piezoresistive material sensor device is embedded within a substrate structure through brazing bonding process, which consists of a Ti6Al4V substrate, a Nickel-chromium thin film sensor and an Alumina insulating layer. The thin-films were characterized by 3D Super Depth Digital Microscope, SEM/EDS, Stylus profiler, to study microstructure, material composition, thickness and sheet resistance respectively. The thin-film strain gauges are calibrated in a cantilever beam setup. Accordingly, in-process cutting force measurement systems are established. The results showed that the thin-film sensor had good linearity and more elaborate structure and superior properties.

Tool wear monitoring and prognostics challenges: a comparison of connectionist methods toward an adaptive ensemble model

In a high speed milling operation the cutting tool acts as a backbone of machining process, which requires timely replacement to avoid loss of costly workpiece or machine downtime. To this aim, prognostics is applied for predicting tool wear and estimating its life span to replace the cutting tool before failure. However, the life span of cutting tools varies between minutes or hours, therefore time is critical for tool condition monitoring. Moreover, complex nature of manufacturing process requires models that can accurately predict tool degradation and provide confidence for decisions. In this context, a data-driven connectionist approach is proposed for tool condition monitoring application. In brief, an ensemble of Summation Wavelet-Extreme Learning Machine models is proposed with incremental learning scheme. The proposed approach is validated on cutting force measurements data from Computer Numerical Control machine. Results clearly show the significance of our proposition.

On the design and analysis of an octagonal–ellipse ring based cutting force measuring transducer

This paper presents study of design, modelling, and analysis of a modified octagonal ring based cutting force measuring transducer. The shape of an octagonal ring was modified by altering the geometry of the circle into an ellipse. The main objective is to increase the strain to the displacement ratio under a given load so that the sensitivity is maximized.Analytical and three-dimensional (3D) finite element (FE) methods were deployed to estimate mechanical responses such as strain, displacement, and stress of the transducer. Results showed that compared to the octagonal ring with circle, the modified octagonal ring with ellipse had maximized the sensitivity by 15% and 25% in axial and tangential loading, respectively.In order to assess the performance of the designed transducer, calibration tests were performed on an Instron machine under axial and tangential loading and cross-sensitivity of force measurements was analysed. Following the ISO 376:2011 standard, an extensive uncertainty evaluation was performed to validate the measurement process used in the calibration.Calibration results showed that the force transducer with the proposed octagonal–ellipse ring was able to measure the force with average error less than 2%. The maximum average error in cross-sensitivity is found to be less than 5% while the overall uncertainty in measurements was up to 1.78%.Based on simulation and calibration test results, the position and the orientation of the strain gauges on the transducer were determined, and a new and compact layout of the 3D cutting force measurement system for milling was then designed and modelled. A frequency analysis was performed to assess the vibrational response of the system. It is expected that the transducer integrated with octagonal–ellipse rings would potentially be a sustainable and cheaper option for small-to-medium sized workshops to accurately measure the milling forces.

Design and Analysis of a Sensor System for Cutting Force Measurement in Machining Processes.

Multi-component force sensors have infiltrated a wide variety of automation products since the 1970s. However, one seldom finds full-component sensor systems available in the market for cutting force measurement in machine processes. In this paper, a new six-component sensor system with a compact monolithic elastic element (EE) is designed and developed to detect the tangential cutting forces Fx, Fy and Fz (i.e., forces along x-, y-, and z-axis) as well as the cutting moments Mx, My and Mz (i.e., moments about x-, y-, and z-axis) simultaneously. Optimal structural parameters of the EE are carefully designed via simulation-driven optimization. Moreover, a prototype sensor system is fabricated, which is applied to a 5-axis parallel kinematic machining center. Calibration experimental results demonstrate that the system is capable of measuring cutting forces and moments with good linearity while minimizing coupling error. Both the Finite Element Analysis (FEA) and calibration experimental studies validate the high performance of the proposed sensor system that is expected to be adopted into machining processes.

一方向CFRPのドリル加工における工具刃数と切削力特性

3 flutes twist drills have recently been used to metal cutting in terms of accuracy of drilled holes. The paper discusses the cutting processes of 2 and 3 flutes drills in drilling of uniaxial carbon fiber reinforced plastic (CFRP). The cutting force depends on the relative angle of the cutting direction with respect to the fiber orientation of workpiece. The changes in the cutting forces with the cutter rotation are analyzed in the cutting force measurement and the cutting simulation based on a force model, where the orthogonal cutting data for the simulation changes with the relative angle of the cutting direction to the fiber orientation. The averages and the periodical amplitudes in the cutting forces are discussed for drilling of 2 and 3 flutes tools. Large cyclic changes in thrust and torque appear in drilling with 2 flutes drill. X and Y components, in contrast, change periodically in drilling with 3 flutes drill.

Study on the Correction of Cutting Force Measurement with Table Dynamometer

This paper studies the correction of cutting force measurement with table dynamometer. The cutting force measurement tests and impact tests are carried out to obtain measured cutting forces and measured transfer function between the measured cutting forces and applied forces, respectively. According to the analysis of these experimental data, it is found that the distorted measured cutting forces are caused by the significant errors of cutting forces at two times and three times tooth passing frequency. Using a Kalman filter technique, the distorted measured cutting forces are corrected. The results of cutting force correction are very well and verify the theory that in frequency domain, cutting forces mainly concentrate on tooth passing frequency.

Sensorless Cutting Force Estimation in Large Scale Ball-Screw-Driven Machine Tool

The cutting force is widely regarded as being the most valuable information when observing a metal cutting process. Considering practicability, indirect cutting force measurement methods which forego additional sensors have been studied in academic field. Disturbance observer-based cutting force estimation method was known as a typical example, and its validity was verified in linear motor driven stage. However, accurate cutting force estimation is still difficult in ball-screw driven stage because of non-linear friction and resonance. In this study, feasibility of sensorless cutting force estimation was verified by using large scale commercial machine tool. Considering that the motion of rotational and translational elements independently, cutting force observer (CFOB) was modeled as two-degree-of-freedom system. The CFOB was mounted to control systems of both stage and spindle head which were driven by ball-screw and servo motor. While friction force and torque have non-linear position dependence, high repeatability was confirmed. Thus, their non-linearity could be attenuated by identifying friction force and torque beforehand machining operation. From experimental results, it was shown that tooth-pass frequency and second harmonics component of the cutting forces could be estimated accurately by using the CFOB. The results were acquired from control systems of both stage and spindle head.

Design and development of a cutting force sensor based on semi-conductive strain gauge

A kind of cutting force sensor based on semi-conductive strain gauge is proposed in this paper in order to optimize the contradiction between sensitivity and natural frequency of strain-gauge type sensors. A new sensing element of two mutual-perpendicular octagonal rings11TMPOR: two mutual-perpendicular octagonal rings. (TMPOR) is developed to improve natural frequency; and semi-conductive strain gauge that fabricated by MEMS (micro-electro-mechanical system) technique is used to enhance sensitivity of the sensor due to its higher gauge factor (GF). Static calibration experiment results show that semi-conductive strain gauge has improved the sensitivity by 16 times than traditional metal foil strain gauge, which proves the feasibility of settling the contradiction aforementioned by using MEMS technique. Modal impact test indicates that the natural frequency of the fabricated sensor is 771Hz in primary direction, which fulfills its most application in high speed machining process. During dynamic cutting force measurement test, the developed sensor exhibits satisfying ability in dynamic cutting force signal detection. Generally, the MEMS technique based sensor shows great potential in solving technical defect between sensitivity and natural frequency in current cutting force sensor research.

Study on machinability of in situ Al–4.5%Cu–TiC metal matrix composite-surface finish, cutting force prediction using ANN

This paper discusses the experimental exploration on chip formation, surface roughness and cutting force measurement throughout the CNC milling operation of Al–4.5%Cu/TiC MMCs produced by the in situ practice and compared the results with those for Al–4.5%Cu/SiC MMCs produced by ex situ technique and with Al–4.5Cu master alloy. The cutting forces were measured during the milling operation with the aid of a dynamometer, surface roughness was measured by using a 3D profilometer, the chips formed were also characterised and compared from the viewpoint of machinability. The present study also explores the potential of artificial neural network to predict the cutting force and surface roughness generated during machining in CNC milling machine.

Sensorless Cutting Force Estimation in Large Scale Ball-Screw-Driven Machine Tool

The cutting force is widely regarded as being the most valuable information when observing a metal cutting process. Considering practicability, indirect cutting force measurement methods which forego additional sensors have been studied in academic field. Disturbance observer-based cutting force estimation method was known as a typical example, and its validity was verified in linear motor driven stage. However, accurate cutting force estimation is still difficult in ball-screw driven stage because of non-linear friction and resonance. In this study, feasibility of sensorless cutting force estimation was verified by using large scale commercial machine tool. Considering that the motion of rotational and translational elements independently, cutting force observer (CFOB) was modeled as two-degree-of-freedom system. The CFOB was mounted to control systems of both stage and spindle head which were driven by ball-screw and servo motor. While friction force and torque have non-linear position dependence, high repeatability was confirmed. Thus, their non-linearity could be attenuated by identifying friction force and torque beforehand machining operation. From experimental results, it was shown that tooth-pass frequency and second harmonics component of the cutting forces could be estimated accurately by using the CFOB. The results were acquired from control systems of both stage and spindle head.

Finite Element Simulation and Experimental Study on Micro-Milling Cobalt-Based Alloy

Elgiloy is a cobalt-based alloy with excellent physical and chemical performance, which is used widely in medical and industrial applications. In this paper, the professional finite element analysis software for metal cutting is used to establish the finite element simulation model of micro cutting this kind of cobalt-based alloy, and the effect of feed rate, which is considered as the most important processing parameter, on the cutting force of micro cutting Elgiloy is analyzed. The cutting force measurement system based on ultra-precision micro milling machine tool is established for experimental study on the cutting force of micro milling Elgiloy by using ultra-fine gain tungsten carbide micro milling tool. The cutting force is measured with different feed rate parameters and the influence of the parameters on the cutting force is analyzed. The simulation and experimental results show that the trends observed at the micro scale are the same as the trends for machining at the macro scale, which implies that the Elgiloy material behaves in a similar manner at both length scales.

Design of a Kalman Filter for a Cutting Force Measurement System

paper presents a Kalman filter designed for a cutting force measurement system. The cutting force measurement system is used to measure cutting forces for meso-milling applications. Due to the small magnitude of the cutting forces generated from the meso-milling process, the measurement results are easily distorted by the noise that exists in the measurement system. The object of the Kalman filter design is to reduce the noise influence and obtain accurate cutting force measurement information for the meso-milling applications. The Kalman filter is designed based on an oscillation process model due to the oscillation characteristic of the cutting forces experienced in the meso-milling process. Keywordsfilter, cutting force measurement, signal filtering, noise reduction

Cutting Forces in Drilling Operation: Measurement and Modeling for Medium-scale Manufacturing Firms

Advanced manufacturing systems often caters to rapidly changing product specification determination by the continuously increasing productivity, flexibility and quality demands. The estimation of cutting forces is mandatory to select tools and accessories for machining. Complex interrelationships exist between process parameters and these forces. In the present work, the applicability and relative effectiveness of artificial neural network based model has been investigated for rapid estimation of cutting forces. The results obtained are found to correlate well with the actual experimental readings of cutting forces. Experiments were conducted at different process parameters of cutting in Drilling operation. The proposed work has wide application in selection of tools and online tool wear monitoring. General Terms Measurement and modeling of Cutting forces.

Setting-Up Of A Cutting Forces Measurement System

Abstract The paper is focused in the field of cutting forces measurement by modern sensors and data acquisition systems. It is presented the measurement chain with its components. Thus, there are presented the piezoelectric sensors that are commonly used in modern cutting forces dynamometers construction, as well as some typical topologies. The measurement system includes a data acquisition system that allows the real time data acquisition during the cutting process. The proposed cutting force measurement system can be used in the measurement of three orthogonal forces in milling processes, as well as the measurement of the torque in drilling processes.

Model-based broadband estimation of cutting forces and tool vibration in milling through in-process indirect multiple-sensors measurements

In machining processes, cutting forces measurement is essential to allow cutting process and tool conditions monitoring. Moreover, in order to have information about the quality of the milled part, the amplitude of the tool tip vibration would be very useful. Since both the measurements are extremely complicated especially in an industrial scenario, in this study, an in-process model-based estimator of cutting forces and tool tip vibration was designed and properly tested. The developed estimator relies on both a machine dynamic model and on indirect measurements coming from multiple sensors placed in the machine. The machine dynamic model was obtained through an experimental modal analysis session. The estimator was developed according to the Kalman filter approach. The fusion of multiple sensors data allowed the compensation of machine tool dynamics over an extended frequency range. The accuracy of the observer estimations was checked performing two different experimental sessions in which both the force applied to the tool and the tool tip vibration amplitude were measured. In the first session, the tool was excited with different sensorized hammers in order to appreciate the broad bandwidth of the performed estimations. In the second one, real cutting tests (steel milling) were done and the cutting forces were measured through a dynamometer; tool tip vibrations were measured as well. The experimental results showed that the indirect estimation of cutting forces and tool tip vibrations exhibit a good agreement with respect to the corresponding measured quantities in low and high frequency ranges. The contribution of this research is twofold. Firstly, the conceived observer allows estimating the tool tip vibrations that is a useful information strictly connected to the surfaces quality of the processed workpiece. Secondly, thanks to a multi-sensors approach, the frequency bandwidth is extended especially in the low frequency range.

Experimental Investigation and Analysis of Cutting Forces When Machining X5CrNi18-10 Stainless Steel

In this study, cutting forces experimental measurement an analysis with special carbide insert when turning austenitic stainless steel have been investigated. Stainless steel X5CrNi18-10 is often considered as poorly machinable material. In this experimental study a number of turning tests carried out by using a test lathe and a cutting force measuring device are presented. Accordingly the effect of cutting speed and tool insert cutting geometry on cutting forces in turning austenitic stainless steel X5CrNi18-10 (AISI 304) using Wiper cemented carbide tool insert has been discussed. The effect of cutting parameters (feed rate, depth of cut) is also analyzed by cutting forces measurement. The input parameters were varied as vc = 100 m.min-1, f = 0,150 and 0,275 mm and edge geometry r = 95°, r'= 5°, εr = 80°, rε = 0, 8 mm, s = -6°. The results show that main cutting force Fc decreases with the increasing of cutting speed in turning without using the coolant. A benefit for production process also confirmed fact that this growth is 2,5 to 3 times higher as for turning of CS0E4 under the same machining conditions due to the hardening of austenitic steels for chip creation. It was also noted that experimental specimens showing larger cutting forces then generated worse surface finish as well as larger surface damage.