scholarly journals The cutting behavior of cortical bone in different bone osten cutting angles and depths of cut

Author(s):  
Yuanqiang Luo ◽  
Yinghui Ren ◽  
Yang Shu ◽  
Cong Mao ◽  
Zhixiong Zhou ◽  
...  

Abstract Cortical bones are semi-brittle and anisotropic, this brings the challenge to suppress vibration and avoid undesired fracture in precise cutting processes in surgeries. In this paper, we proposed a novel analytical model to represent cutting processes of cortical bones, and we used to evaluate cutting forces and fracture toughness, and investigate the formations of chips and cracks under varying bone osteon cutting angles and depths. To validate the proposed model, the experiments are conducted on orthogonal cuttings over cortical bones to investigate the impact of bone osteon cutting angle and depth on cutting force, crack initialization and growth, and fracture toughness of cortical bone microstructure. The experimental results highly agreed with the prediction by the proposed model in sense that (1) curly, serrated, grainy and powdery chips were formed when the cutting angle was set as 0°, 60°, 90°, and 120°, respectively. (2) Bone materials were removed dominantly by shearing at a small depth of cut from 10 to 50 µm, and by a mixture of pealing, shearing, and bending at a large depth of cut over 100 µm at different cutting orientations. Moreover, it was found that a cutting path along the direction of crack initialization and propagation benefited to suppress the fluctuation of cutting force thus reduce the vibration. The presented model has theoretical and practical significance in optimizing cutting tools and operational parameters in surgeries.

2021 ◽  
pp. 089270572199320
Author(s):  
Prakhar Kumar Kharwar ◽  
Rajesh Kumar Verma

The new era of engineering society focuses on the utilization of the potential advantage of carbon nanomaterials. The machinability facets of nanocarbon materials are passing through an initial stage. This article emphasizes the machinability evaluation and optimization of Milling performances, namely Surface roughness (Ra), Cutting force (Fc), and Material removal rate (MRR) using a recently developed Grey wolf optimization algorithm (GWOA). The Taguchi theory-based L27 orthogonal array (OA) was employed for the Machining (Milling) of polymer nanocomposites reinforced by Multiwall carbon nanotube (MWCNT). The second-order polynomial equation was intended for the analysis of the model. These mathematical models were used as a fitness function in the GWOA to predict machining performances. The ANOVA outcomes efficiently explore the impact of machine parameters on Milling characteristics. The optimal combination for lower surface roughness value is 1.5 MWCNT wt.%, 1500 rpm of spindle speed, 50 mm/min of feed rate, and 3 mm depth of cut. For lower cutting force, 1.0 wt.%, 1500 rpm, 90 mm/min feed rate and 1 mm depth of cut and the maximize MRR was acquired at 0.5 wt.%, 500 rpm, 150 mm/min feed rate and 3 mm depth of cut. The deviation of the predicted value from the experimental value of Ra, Fc, and MRR are found as 2.5, 6.5 and 5.9%, respectively. The convergence plot of all Milling characteristics suggests the application potential of the GWO algorithm for quality improvement in a manufacturing environment.


2019 ◽  
Vol 9 (1) ◽  
pp. 65-72
Author(s):  
Mohammad Zaher Akkad ◽  
Felhő Csaba

This paper presents a study about the workpiece force components (Fx, Fy, Fz) changes in face milling, which results from changing the depth of cut and the feed rate values. The values of the three force components in the face milling operation were found through the FEA-software AdvantEdge by Third Wave Systems. This program is uniquely intended for modelling of cutting processes. Simulations were carried out within five different cutting depth of cut and feed rate, to compare the obtained values and find out the results of the impact of changes on the three force components.


Author(s):  
Andrew M. Phan ◽  
John P. Parmigiani

Cutting operations using blades appear in several different industries such as food processing, surgical operations, gardening equipment, and so forth. Many practitioners of cutting operations will notice that it is easier to cut something by pressing and slicing at the same time versus doing each motion individually. They will also notice that certain angles or certain blade geometries make it easier to cut certain materials. As our society continues to increase our technological prowess, there is an ongoing need to better understand the underlying causes of simple tasks such as cutting so that cutting operations can be performed with more precision and accuracy than ever before. For many applications it is not possible to achieve the most optimum cutting force, cutting angle, and push to slice ratio and a compromise must be made in order to ensure the functionality of a cutting device. A means of objectively and efficiently evaluating cutting media is needed in order to determine the optimum parameters such as cutting force, cutting angle, and push to slice ratio for certain applications. The approach taken in this work is to create a testing apparatus that uses standard cutting media and performs controlled cutting operations to determine key parameters to specific cutting operations. Most devices used for performing experimental controlled cutting operations are limited to a single axis of motion, thus not incorporating the effect of the push to slice ratio. The device created and discussed in this paper is capable of performing controlled cutting operations with three axes of motion. It is capable of accurately controlling the depth of cut, push to slice ratio, and angle of cut in order to accurately capture motions seen in typical cutting operations. Each degree of freedom on the device is capable of withstanding up to 1550 N of cutting force while still capable of maintaining smooth motions. The device is capable of controlling the velocity of the push and slice motions up to 34 mm/s. Depth of cut, for both pushing and slicing, the reaction forces, and the angle of cut are all controlled and measured in real-time so that a correlation can be made between them. Data collected by this device will be used to investigate the effects of the push to slice ratio and angle of cut on cutting force and overall quality of cutting operations. Preliminary testing in wood test samples evaluates the effectiveness of the device in collecting cutting data. This device will also be used to validate several finite element analyses used in investigating cutting mechanics.


2018 ◽  
Vol 38 (1) ◽  
pp. 40-44
Author(s):  
Krzysztof Jarosz ◽  
Piotr Niesłony ◽  
Piotr Löschner

Abstract In this article, a novel approach to computer optimization of CNC toolpaths by adjustment of cutting speed vcand depth of cut apis presented. Available software works by the principle of adjusting feed rate on the basis of calculations and numerical simulation of the machining process. The authors wish to expand upon this approach by proposing toolpath optimization by altering two other basic process parameters. Intricacies and problems related totheadjustment of apand vcwere explained in the introductory part. Simulation of different variant of the same turning process with different parameter values were conducted to evaluate the effect of changes in depth of cut and cutting speed on process performance. Obtained results were investigated on the account of cutting force and tool life. The authors have found that depth of cut substantially affects cutting force, while the effect of cutting speed on it is minimal. An increase in both depth of cut and cutting speed affects tool life negatively, although the impact of cutting speed is much more severe. An increase in depth of cut allows for a more significant reduction of machining time, while affecting tool life less negatively. On the other hand, the adjustment of cutting speed helpsto reduce machining time without increasing cutting force component values and spindle load.


2013 ◽  
Vol 554-557 ◽  
pp. 2009-2020 ◽  
Author(s):  
Volker Schulze ◽  
Frederik Zanger ◽  
Florian Ambrosy

The present work analyzes the influence of an orthogonal machining process on the generation of nanocrystalline surface layers. Thereby, AISI 4140 is used as work piece material. Metallic parts with a severe nanocrystalline grain refinement in the near-surface area show many beneficial properties. Such surface layers considerably influence the friction and wear characteristics of the work piece in a subsequent usage as design elements working under tribological loads. The focus of this paper is an experimental analysis of a finishing orthogonal cutting operation, carried out with a broaching machine, to generate nanocrystalline surface layers. The influence of process and geometry parameters on the generation of nanocrystalline surfaces is investigated with the aim to massively decrease the grain size in the work piece surface layer. Parameters that are studied and taken into account in the manufacturing process are cutting edge radius rβ, depth of cut h and cutting velocity vc. The cutting edge radius rβ is modified by a drag finishing process. The generation of nanocrystalline surface layers is especially influenced by the design of the uncoated carbide cutting tools. Additionally, cutting force Fc and passive force Fp are determined by a 3-component dynamometer to calculate the relationship between specific cutting force kc and specific passive force kp. The temperature beneath the clearance face is detected by a fiber optic pyrometer. These measurement methods and devices are applied to detect the impact of the most relevant measurement values occurring during machining and causing a drastic reduction of grain size in the surface layer. The evaluation of the manufacturing process is carried out by detailed analyses of the microstructural conditions in the surface layer after processing using a Focused Ion Beam (FIB) system. These material characterizations provide information about the surface engineering concerning the microstructural changes in the surface layer of the work piece due to finishing orthogonal cutting processes.


Author(s):  
Hai Trong Nguyen ◽  
Hui Wang ◽  
S. Jack Hu

High-definition metrology (HDM) systems with fine lateral resolution are capable of capturing the surface shape on a machined part that is beyond the capability of measurement systems employed in manufacturing plants today. Such surface shapes can precisely reflect the impact of cutting processes on surface quality. Understanding the cutting processes and the resultant surface shape is vital to high-precision machining process monitoring and control. This paper presents modeling and experiments of a face milling process to extract surface patterns from measured HDM data and correlate these patterns with cutting force variation. A relationship is established between the instantaneous cutting forces and the observed dominant surface patterns along the feed and circumferential directions for face milling. Potential applications of this relationship in process monitoring, diagnosis, and control are also discussed for face milling. Finally a systematic methodology for characterizing cutting force induced surface variations for a generic machining process is presented by integrating cutting force modeling and HDM measurements.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1726
Author(s):  
S. Parasuraman ◽  
I. Elamvazuthi ◽  
G. Kanagaraj ◽  
Elango Natarajan ◽  
A. Pugazhenthi

Reinforced aluminum composites are the basic class of materials for aviation and transport industries. The machinability of these composites is still an issue due to the presence of hard fillers. The current research is aimed to investigate the drilling topographies of AA7075/TiB2 composites. The samples were prepared with 0, 3, 6, 9 and 12 wt.% of fillers and experiments were conducted by varying the cutting speed, feed, depth of cut and tool nose radius. The machining forces and surface topographies, the structure of the cutting tool and chip patterns were examined. The maximum cutting force was recorded upon increase in cutting speed because of thermal softening, loss of strength discontinuity and reduction of the built-up-edge. The increased plastic deformation with higher cutting speed resulted in the excess metal chip. In addition, the increase in cutting speed improved the surface roughness due to decrease in material movement. The cutting force was decreased upon high loading of TiB2 due to the deterioration of chips caused by fillers. Further introduction of TiB2 particles above 12 wt.% weakened the composite; however, due to the impact of the microcutting action of the fillers, the surface roughness was improved.


Author(s):  
Akhtar Khan ◽  
Kalipada Maity

The present work explores the application of a novel Multi-Criteria Decision Making (MCDM) based approach known as VIKOR analysis combined with Taguchi technique for simultaneous optimization of some correlated cutting variables in turning of commercially pure titanium grade 2 using uncoated carbide inserts. The experiments have been carried out according to Taguchi’s L27 orthogonal array. Three input variables viz. cutting speed, feed rate and depth of cut have been taken at three different levels. The impact of these cutting variables on cutting force, surface quality and material removal rate has been investigated. The optimal combination of machining parameters has been evaluated to minimize the cutting force and to maximize the surface finish and production rate using MCDM based VIKOR analysis method. ANOVA (analysis of variance) test has been performed to determine the most influencing cutting variable on overall quality measure i.e. VIKOR index (Qi). The optimal setting of machining variables has been shown using main effects plot for S/N ratio for Qi. The results of ANOVA exhibit that the cutting speed is the governing machining parameter followed by feed rate on overall quality index (Qi). The minimum (desirable) value of Qi is achieved at the parametric combination of v3-f1-d3 i.e. cutting speed (110 m/min), feed rate (0.08 mm/rev) and depth of cut (0.4 mm) respectively. The feasibility of the proposed methodology has been verified by conducting a confirmation test.


Author(s):  
Hai Trong Nguyen ◽  
Hui Wang ◽  
S. Jack Hu

High-definition metrology (HDM) systems with fine lateral resolution are capable of capturing the surface shape on a machined part that is beyond the scope of measurement systems employed in manufacturing plants today. Such surface shapes can precisely reflect the impact of cutting processes on surface quality. Understanding the cutting processes and the resultant surface shape is vital to identifying opportunities for high-precision machining process monitoring and control. This paper presents modeling and experiments of a face milling process to extract surface patterns from measured HDM data and correlate these patterns with cutting force variation. A relation is established between instantaneous cutting forces and the observed dominant patterns along the feed and circumferential directions. Potential applications of such relationship in process monitoring, diagnosis, and control are also discussed.


Sign in / Sign up

Export Citation Format

Share Document