Modeling of Gear Hobbing: Part II — A Computer Supported Experimental-Analytical Determination of the Wear Progress to Optimize the Tool Life Time

1999 ◽  
Author(s):  
Konstantinos D. Bouzakis ◽  
Spiros Kombogiannis ◽  
Aristomenis Antoniadis ◽  
Nectarios Vidakis
Keyword(s):  
Tool Wear ◽  
Prediction Models ◽  
Digital Simulation ◽  
Life Time ◽  
Analytical Determination ◽  
Tool Wear Prediction ◽  
Gear Hobbing ◽  
User Friendly ◽  
Continuous Enrichment

Abstract Tool wear prediction models for gear hobbing were presented in the first part of this paper. To determine the constants of the equations used in these models, fly hobbing experiments with uncoated and coated HSS tools were conducted. Hereby, it was necessary to modify the fly hobbing kinematics from continuous tangential feed to continuous axial feed. The experimental data were evaluated, and correlated to the analytical ones, elaborated through the described digital simulation of the cutting process. The determined constants of the wear laws for the investigated tools were used in a further developed user friendly software, enabling the prediction of the tool wear accomplishment in gear hobbing. On that account the wear development can be precisely foreseen and the tangential shift of the tool is optimized. The open and modular structure of the developed code enables the continuous enrichment of its database with other type of coating and workpiece materials. With the aid of the aforementioned techniques, the superiority of coated HSS tools in comparison to uncoated ones is also quantitatively exhibited.

Gear Hobbing Cutting Process Simulation and Tool Wear Prediction Models

2001 ◽  
Vol 124 (1) ◽  
pp. 42-51 ◽  
Author(s):  
K.-D. Bouzakis ◽  
S. Kombogiannis ◽  
A. Antoniadis ◽  
N. Vidakis
Keyword(s):  
Tool Wear ◽  
High Speed ◽  
Prediction Models ◽  
Numerical Models ◽  
High Speed Steel ◽  
Cutting Process ◽  
Wear Prediction ◽  
Tool Wear Prediction ◽  
Gear Hobbing ◽  
The Individual

Gear hobbing is an efficient method to manufacture high quality and performance toothed wheels, although it is associated with complicated process kinematics, chip formation and tool wear mechanisms. The variant cutting contribution of each hob tooth to the gear gaps formation might lead to an uneven wear distribution on the successive cutting teeth and to an overall poor tool utilization. To study quantitatively the tool wear progress in gear hobbing, experimental-analytical methods have been established. Gear hobbing experiments and sophisticated numerical models are used to simulate the cutting process and to correlate the undeformed chip geometry and other process parameters to the expected tool wear. Herewith the wear development on the individual hob teeth can be predicted and the cutting process optimized, among others, through appropriate tool tangential shifts, in order to obtain a uniform wear distribution on the hob teeth. To determine the constants of the equations used in the tool wear calculations, fly hobbing experiments were conducted. Hereby, it was necessary to modify the fly hobbing kinematics, applying instead of a continuous tangential feed, a continuous axial one. The experimental data with uncoated and coated high speed steel (HSS) tools were evaluated, and correlated to analytical ones, elaborated with the aid of the numerical simulation of gear hobbing. By means of the procedures described in this paper, tool wear prediction as well as the optimization of various magnitudes, as the hob tangential shift parameters can be carried out.

Modeling of Gear Hobbing: Part I — Cutting Simulation and Tool Wear Prediction Models

1999 ◽  
Author(s):  
Konstantinos D. Bouzakis ◽  
Spiros Kombogiannis ◽  
Aristomenis Antoniadis ◽  
Nectarios Vidakis
Keyword(s):  
Tool Wear ◽  
Cutting Tool ◽  
Prediction Models ◽  
Cutting Parameters ◽  
Tool Wear Prediction ◽  
Gear Hobbing ◽  
Uneven Wear ◽  
And Performance ◽  
The Individual ◽  
Chip Geometry

Abstract Gear hobbing is the most common method to manufacture high quality and performance toothed wheels. The gear hobbing kinematics induces complicated chip formation and is characterized by convoluted wear mechanisms of the cutting tool. The variant cutting contribution of each cutting tooth is responsible for the uneven wear distribution on the successive hob teeth and the poor utilization of the entire cutting tool. Moreover, the gear width influences the chip geometry in the tool entry and exit regions into the workpiece, and sets a mathematical wear description even more complicated. To study quantitatively the tool wear progress in gear hobbing, experimental-analytical methods have been established. Gear hobbing experiments and advanced mathematical models are hired to correlate the undeformed chip geometry and other cutting parameters with the anticipated wear. With the aid of such procedures and of appropriate constants, essential for the description of the wear development in the individual gear gaps generating positions, an optimization of the hobbing process can be achieved. Hence, among others, appropriate tangential shifts of the hobbing tool may be predicted.

Modeling of Thrust Force and Tool Wear and Optimization of Process Parameters in Drilling Nickel-Based Alloy GH536

2011 ◽  
Vol 188 ◽  
pp. 360-363
Author(s):  
M.H. Wang ◽  
Shu Tao Huang
Keyword(s):  
Tool Wear ◽  
Tool Life ◽  
Process Parameters ◽  
Prediction Models ◽  
Thrust Force ◽  
Drilling Process ◽  
Cutting Efficiency ◽  
Optimization Of Process Parameters ◽  
Tool Wear Prediction ◽  
Nickel Based Alloy

. In this study, the prediction models of thrust force, tool wear and torque in drilling nickel-based alloy GH536 are developed based genetic algorithm and drilling experiments. Tool wear value is used as constraint condition and maximum cutting efficiency as goal to optimize drilling process parameters. In addition, the relationship between tool life and cutting efficiency is analyzed by exploiting the tool wear prediction model. The results of the analysis show that under the condition of efficiency remains unchanged, the tool life can be increased by increasing drilling speed and appropriately reducing feed rate, these results are consistent with the optimized process parameters.

Hidden Markov Model for Health Estimation and Prognosis of Turbofan Engines

2011 ◽  
Author(s):  
Andrea Giantomassi ◽  
Francesco Ferracuti ◽  
Alessandro Benini ◽  
Gianluca Ippoliti ◽  
Sauro Longhi ◽  
...  
Keyword(s):  
Markov Model ◽  
Hidden Markov Model ◽  
Prediction Models ◽  
Residual Life ◽  
Hidden Markov ◽  
Life Time ◽  
Turbofan Engines ◽  
Useful Life ◽  
Determinant Factor

Determining the residual life time of systems is a determinant factor for machinery and environment safety. In this paper the problem of estimate the residual useful life (RUL) of turbo-fan engines is addressed. The adopted approach is especially suitable for situations in which a large amount of data is available offline, by allowing the processing of such data for the determination of RUL. The procedure allows to calculate the RUL through the following steps: features extraction by Artificial Neural Networks (ANN) and determination of remaining life time by-prediction models based on a Hidden Markov Model (HMM). Simulations confirm the effectiveness of the proposed approach and the promising power of Bayesian methods.

Simplified Analytical Determination of Bending Moments in a Two-Way Slab Using a Web-Based Application

2021 ◽  
Vol 108 ◽  
pp. 45-52
Author(s):  
Jakub Holan ◽  
Radek Štefan
Keyword(s):  
Reinforced Concrete ◽  
Analytical Methods ◽  
Analytical Determination ◽  
Correction Coefficient ◽  
The Novel ◽  
Bending Moments ◽  
Web Based ◽  
User Friendly ◽  
Analytical Approaches

In the last decade, the computing power of computers has significantly increased, which enabled very detailed and accurate numerical static non-linear analyses of reinforced concrete structures to be carried out using sophisticated commercial software. However, higher risk of errors, both in the calculation inputs and algorithm, is linked with the increased detail and accuracy of numerical modelling. For this reason, it is convenient to verify the results provided by sophisticated software using simplified analytical approaches. In order to provide a tool for quick and easy verification of results provided by sophisticated software, a novel web-based application employing simplified analytical methods has been developed by the authors of this paper. This web-based application is capable of quick and easy calculations of bending moments in reinforced concrete two-way slabs. For the calculation of bending moments, the Marcus Method is employed. This method introduces a correction coefficient to the Rankine-Grashoff Theory of Equal Deflections in order to account for the torsional restraints at the corners of the slab. These analytical methods are algorithmized and implemented using the JavaScript programming language. A graphical user interface for the input of data and for the interpretation of results is created using the HTML markup language. The novel web-based application is freely available and works on all common devices and operating systems. From the presented results, it is clear that the novel web-based application is quick, easily available, user-friendly, and intuitive. The web-based application can be used for the verification of the calculated bending moments during the design of a reinforced concrete two-way slab.

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