Effective corner machining via a constant feed rate looping tool path

2013 ◽  
Vol 51 (6) ◽  
pp. 1836-1851 ◽  
Author(s):  
A.K.M. Arifur Rahman ◽  
Hsi-Yung Feng
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
Corner Machining ◽  
Constant Feed Rate

Nonisochoric Reactor with Constant Feed Rate of One Component

1993 ◽  
Vol 58 (7) ◽  
pp. 1476-1484
Author(s):  
Václav Dušek ◽  
František Skopal
Keyword(s):  
Sulfuric Acid ◽  
Acid Medium ◽  
Feed Rate ◽  
Redox System ◽  
Chemical Reactor ◽  
Constant Volume ◽  
Rate Equations ◽  
Sulfuric Acid Medium ◽  
Constant Feed Rate

For a chemical reactor with constant volume feed rate equations have been derived which describe the time dependences of concentration of the reaction components, and their approximation has been suggested. The applicability of the approximation has been verified on a model redox system Ce(IV)/V(IV) in sulfuric acid medium.

Micro Flat End Milling Simulation Model With Instantaneous Plowing Area Prediction

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Abdolreza Bayesteh ◽  
Junghyuk Ko ◽  
Martin Byung-Guk Jun
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
End Milling ◽  
Chip Thickness ◽  
Depth Of Cut ◽  
Uncut Chip Thickness ◽  
Chip Area ◽  
Edge Radius ◽  
Wide Range ◽  
Radial Depth

There is an increasing demand for product miniaturization and parts with features as low as few microns. Micromilling is one of the promising methods to fabricate miniature parts in a wide range of sectors including biomedical, electronic, and aerospace. Due to the large edge radius relative to uncut chip thickness, plowing is a dominant cutting mechanism in micromilling for low feed rates and has adverse effects on the surface quality, and thus, for a given tool path, it is important to be able to predict the amount of plowing. This paper presents a new method to calculate plowing volume for a given tool path in micromilling. For an incremental feed rate movement of a micro end mill along a given tool path, the uncut chip thickness at a given feed rate is determined, and based on the minimum chip thickness value compared to the uncut chip thickness, the areas of plowing and shearing are calculated. The workpiece is represented by a dual-Dexel model, and the simulation properties are initialized with real cutting parameters. During real-time simulation, the plowed volume is calculated using the algorithm developed. The simulated chip area results are qualitatively compared with measured resultant forces for verification of the model and using the model, effects of cutting conditions such as feed rate, edge radius, and radial depth of cut on the amount of shearing and plowing are investigated.

A study on the effect of cooling on microstructure and mechanical properties of friction stir-welded AA5086 aluminum butt and lap joints

2017 ◽  
Vol 233 (6) ◽  
pp. 1156-1165 ◽  
Author(s):  
Adel Sedaghati ◽  
Hamed Bouzary
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Feed Rate ◽  
Rotational Speed ◽  
Lap Joints ◽  
Tensile Behavior ◽  
Water Cooling ◽  
Friction Stir ◽  
Microstructural Behavior ◽  
Constant Feed Rate

In this paper, the effect of water cooling on mechanical properties and microstructure of AA5086 aluminum joints during friction stir welding is investigated. For doing so, the mechanical and microstructural behavior of samples welded both in air and in water was analyzed. Tests were performed involving both butt and lap welds and the results were compared. The effect of rotational speed at constant feed rate of 50 mm/min and changing rotational speed ranging from 250 to 1250 r/min was investigated. The results showed a significant change in the tensile behavior of the butt-welded specimens due to water cooling. In addition, welding was performed at constant spindle speed of 800 r/min and various traverse speeds (25 mm/min to 80 mm/min) to determine the effect of feed rate. The strength increases at first, but then decreases dramatically along with the feed rate which is due to the occurrence of a groove defect. Results showed some generally positive impacts of water cooling which are discussed in terms of tensile results, hardness distributions and microstructure analysis.

Characterizing the Effect of Cutting Condition, Tool Path, and Heat Treatment on Cutting Forces of Selective Laser Melting Spherical Component in Five-Axis Milling

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Amir Mahyar Khorasani ◽  
Ian Gibson ◽  
Moshe Goldberg ◽  
Guy Littlefair
Keyword(s):  
Heat Treatment ◽  
Production Process ◽  
Cutting Force ◽  
Feed Rate ◽  
Cutting Forces ◽  
Tool Path ◽  
Annealing Temperature ◽  
Spindle Speed ◽  
Cutting Condition ◽  
Scallop Height

Additive manufacturing (AM), partly due to its compatibility with computer-aided design (CAD) and fabrication of intricate shapes, is an emerging production process. Postprocessing, such as machining, is particularly necessary for metal AM due to the lack of surface quality for as-built parts being a problem when using as a production process. In this paper, a predictive model for cutting forces has been developed by using artificial neural networks (ANNs). The effect of tool path and cutting condition, including cutting speed, feed rate, machining allowance, and scallop height, on the generated force during machining of spherical components such as prosthetic acetabular shell was investigated. Also, different annealing processes like stress relieving, mill annealing and β annealing have been carried out on the samples to better understand the effect of brittleness, strength, and hardness on machining. The results of this study showed that ANN can accurately apply to model cutting force when using ball nose cutters. Scallop height has the highest impact on cutting forces followed by spindle speed, finishing allowance, heat treatment/annealing temperature, tool path, and feed rate. The results illustrate that using linear tool path and increasing annealing temperature can result in lower cutting force. Higher cutting force was observed with greater scallop height and feed rate while for higher finishing allowance, cutting forces decreased. For spindle speed, the trend of cutting force was increasing up to a critical point and then decreasing due to thermal softening.

Virtual Five-Axis Flank Milling of Jet Engine Impellers—Part II: Feed Rate Optimization of Five-Axis Flank Milling

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
W. B. Ferry ◽  
Y. Altintas
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
Fixed Time ◽  
Flank Milling ◽  
Tool Deflection ◽  
Jet Engine ◽  
Root Finding ◽  
Five Axis ◽  
Feed Rate Optimization ◽  
Chip Load

This paper presents process optimization for the five-axis flank milling of jet engine impellers based on the mechanics model explained in Part I. The process is optimized by varying the feed automatically as the tool-workpiece engagements, i.e., the process, vary along the tool path. The feed is adjusted by limiting feed-dependent peak outputs to a set of user-defined constraints. The constraints are the tool shank bending stress, tool deflection, maximum chip load (to avoid edge chipping), and the torque limit of the machine. The linear and angular feeds of the tool are optimized by two different methods—a multiconstraint based virtual adaptive control of the process and a nonlinear root-finding algorithm. The five-axis milling process is simulated in a virtual environment, and the resulting process outputs are stored at each position along the tool path. The process is recursively fitted to a first-order process with a time-varying gain and a fixed time constant, and a simple proportional-integral controller is adaptively tuned to operate the machine at threshold levels by manipulating the feed rate. As an alternative to the virtual adaptive process control, the feed rate is optimized by a nonlinear root-finding algorithm. The virtual cutting process is modeled as a black box function of feed and the optimum feed is solved for iteratively, respecting tool stress, tool deflection, torque, and chip load constraints. Both methods are shown to produce almost identical optimized feed rate profiles for the roughing tool path discussed in Paper I. The new feed rate profiles are shown to considerably reduce the cycle time of the impeller while avoiding process faults that may damage the part or the machine.

Quintic Spline Interpolation With Minimal Feed Fluctuation

2005 ◽  
Vol 127 (2) ◽  
pp. 339-349 ◽  
Author(s):  
Kaan Erkorkmaz ◽  
Yusuf Altintas
Keyword(s):  
Real Time ◽  
Feed Rate ◽  
Tool Path ◽  
Interpolation Method ◽  
Spline Interpolation ◽  
Tracking Error ◽  
Arc Length ◽  
Quintic Spline ◽  
Rate Profile ◽  
Spline Parameter

This paper presents a parameterization and an interpolation method for quintic splines, which result in a smooth and consistent feed rate profile. The discrepancy between the spline parameter and the actual arc length leads to undesirable feed fluctuations and discontinuity, which elicit themselves as high frequency acceleration and jerk harmonics, causing unwanted structural vibrations and excessive tracking error. Two different approaches are presented that alleviate this problem. The first approach is based on modifying the spline tool path so that it is optimally parameterized with respect to its arc length, which allows it to be accurately interpolated in real-time with minimal complexity. The second approach is based on scheduling the spline parameter to accurately yield the desired arc displacement (hence feed rate), either by approximation of the relationship between the arc length and the spline parameter with a feed correction polynomial, or by solving the spline parameter iteratively in real-time at each interpolation step. This approach is particularly suited for predetermined spline tool paths, which are not arc-length parameterized and cannot be modified. The proposed methods have been compared to approximately arc-length C3 quintic spline parameterization (Wang, F.-C., Wright, P. K., Barsky, B. A., and Yang, D. C. H., 1999, “Approximately Arc-Length Parameterized C3 Quintic Interpolatory Splines,” ASME J. Mech. Des, 121, No. 3., pp. 430–439) and first- and second-order Taylor series interpolation techniques (Huang, J.-T., and Yang, D. C. H., 1992, “Precision Command Generation for Computer Controlled Machines,” Precision Machining: Technology and Machine Development and Improvement, ASME-PED 58, pp. 89–104; Lin, R.-S. 2000, “Real-Time Surface Interpolator for 3-D Parametric Surface Machining on 3-Axis Machine Tools,” Intl. J. Mach. Tools Manuf., 40, No.10, pp. 1513–1526) in terms of feed rate consistency, computational efficiency, and experimental contouring accuracy.

scholarly journals Development and Optimization of a Manual Fed Cassava Root Chipper for Household Cassava Processors

2020 ◽  
pp. 283-295
Author(s):  
Macmanus NDUKWU ◽  
Gabriel AFAM ◽  
Nnaemeka NWAKUBA
Keyword(s):  
Moisture Content ◽  
Feed Rate ◽  
Initial Moisture Content ◽  
Throughput Capacity ◽  
Optimum Thickness ◽  
Cassava Root ◽  
Effect Of Moisture ◽  
Machine Speed ◽  
Content Range ◽  
Constant Feed Rate

A motorized, manual fed cassava root chipping machine was developed, evaluated and optimized. The objective of the research is to investigate the effect of moisture content and speed on the chipping sizes, efficiency, throughput and machine capacities. Obtained results showed that the cassava initial moisture content significantly affected the chipping size, machine capacity, throughput capacity and chipping efficiency within the tested moisture content range of 52 to 68% w.b. The machine speed also affected the chipping size, chipping efficiency, machine and throughput capacity. The average chipping size for the cassava chips at the four ranges of moisture content, speeds and constant feed rate of 89±26.6 kg h-1 ranged from 0.56 to 0.96 cm with optimum thickness 0.618 at 450 rpm and moisture content of 65.27% based on desirability factor. The average chipping efficiency ranged from 60 to 90% with an optimum value of 79.57% at 533 rpm and moisture content of 68 % while the throughput capacities of the machine ranged from 49 to118 kg/h with optimum value of 118 kg/h at a speed of 600 rpm and 68% moisture content.

Study on hole machining for the constant feed rate of Al2O3 engineering ceramics through low-frequency axial vibration

2019 ◽  
Vol 234 (6-7) ◽  
pp. 971-979
Author(s):  
Lei Zheng ◽  
Chen Zhang ◽  
Xianglong Dong ◽  
Yong Feng ◽  
Wendong Wei ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Low Frequency ◽  
Wall Surface ◽  
Axial Vibration ◽  
Drilling Force ◽  
Edge Chipping ◽  
Engineering Ceramics ◽  
Hole Machining ◽  
Constant Feed Rate

Engineering ceramics are increasingly extensively applied in the aerospace, vehicle, armor protection and other fields due to their excellent performances such as high compression strength, high hardness, low density and high protection performance. However, engineering ceramics are typical difficult-to-machine materials, especially in the hole machining under constant feed rate, which limits the promotion and application. In this study, by combining a specially developed novel thin-wall diamond trepanning bit with a low-frequency axial vibration machining, the hole machining process for the constant feed rate of Al2O3 engineering ceramics was experimentally studied and the influence of the low-frequency axial vibration process on the axial drilling force, hole-wall surface roughness and edge chipping size of holes machined was analyzed. The results showed that the low-frequency axial vibration machining obtained a lower axial drilling force and a smaller edge chipping size compared to the traditional drilling process. Moreover, both the axial drilling force and the edge chipping size declined markedly with the rise in amplitude. However, the hole-wall surface roughness presented a rising trend due to the hammering effect of vibration. The process technology proposed in this article realizes the hole machining for a constant feed rate of Al2O3 engineering ceramics and provides a reference for the engineering lot-size hole machining of engineering ceramics.

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