In-Process Monitoring of the Machining State in Superfinishing by Measuring the Dynamic Machining Forces

2016 ◽  
Vol 1136 ◽  
pp. 592-596
Author(s):  
Takashi Onishi ◽  
Kazuhito Ohashi ◽  
Kohei Higashi ◽  
Yohei Morinaka ◽  
Shinichi Banno ◽  
...  
Keyword(s):  
Process Monitoring ◽  
Machining Process ◽  
Dynamic Component ◽  
Machining Forces ◽  
Sliding Surfaces ◽  
Machining Conditions ◽  
Machining Force ◽  
Finished Surface ◽  
The Relationship

Superfinishing is widely used as a final finishing method for sliding surfaces of bearings. In superfinishing, a fine finished surface can be obtained by transiting the machining states from the cutting action to the finishing one as the tool loading is encouraged. To obtain good machining conditions, it is necessary to judge the transition of the machining state reliably. However, it is difficult to judge the transition of the machining states. In this study, we focused on the change of the dynamic component of the machining force, which was applied to the oscillation direction of the superfinishing stone, during machining process. With machining experiments, the relationship between the declination of the dynamic machining force and the transition of the machining state was confirmed.

scholarly journals A Novel Finite Element Method Approach in the Modelling of Edge Trimming of CFRP Laminates

2021 ◽  
Vol 11 (11) ◽  
pp. 4743
Author(s):  
Fernando Cepero-Mejias ◽  
Nicolas Duboust ◽  
Vaibhav A. Phadnis ◽  
Kevin Kerrigan ◽  
Jose L. Curiel-Sosa
Keyword(s):  
Finite Element ◽  
Tool Wear ◽  
Cutting Tool ◽  
Machining Process ◽  
Machining Forces ◽  
General Terms ◽  
Numerical Predictions ◽  
Composite Damage ◽  
Edge Trimming ◽  
Optimal Cutting Parameters

Nowadays, the development of robust finite element models is vital to research cost-effectively the optimal cutting parameters of a composite machining process. However, various factors, such as the high computational cost or the complicated nature of the interaction between the workpiece and the cutting tool significantly hinder the modelling of these types of processes. For these reasons, the numerical study of common machining operations, especially in composite machining, is still minimal. This paper presents a novel approach comprising a mixed multidirectional composite damage mode with composite edge trimming operation. An ingenious finite element framework which infer the cutting edge tool wear assessing the incremental change of the machining forces is developed. This information is essential to replace tool inserts before the tool wear could cause severe damage in the machined parts. Two unidirectional carbon fibre specimens with fibre orientations of 45∘ and 90∘ manufactured by pre-preg layup and cured in an autoclave were tested. Excellent machining force predictions were obtained with errors below 10% from the experimental trials. A consistent 2D FE composite damage model previously performed in composite machining was implemented to mimic the material failure during the machining process. The simulation of the spring back effect was shown to notably increase the accuracy of the numerical predictions in comparison to similar investigations. Global cutting forces simulated were analysed together with the cutting tool tooth forces to extract interesting conclusions regarding the forces received by the spindle axis and the cutting tool tooth, respectively. In general terms, vertical and normal forces steadily increase with tool wear, while tangential to the cutting tool, tooth and horizontal machining forces do not undergo a notable variation.

scholarly journals The Invisible and the Hidden within the Phenomenological Situation of Appearing

Open Theology ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 547-556
Author(s):  
Martin Nitsche
Keyword(s):  
Phenomenological Method ◽  
Dynamic Component ◽  
The Relationship ◽  
The Invisible

AbstractThis study focuses on various phenomenological conceptions of the invisible in order to consider to what extent and in what way they involve moments of hiddenness. The relationship among phenomenality, invisibility, and hiddenness is examined in the works of Husserl, Heidegger, Henry, and Merleau-Ponty. The study explains why phenomenologists prefer speaking about the invisible over a discourse of the hidden. It shows that the phenomenological method does not display the invisibility as a limit of experience but rather as a dynamic component of relational nature of any experience, including the religious one. Special attention is paid to topological moments of the relationship between the visible and the invisible.

Effects of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints

2021 ◽  
pp. 095440542110285
Author(s):  
Xuda Qin ◽  
Xingfeng Cao ◽  
Hao Li ◽  
Meng Zhou ◽  
Ende Ge ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Bolted Joints ◽  
Fatigue Performance ◽  
Machining Process ◽  
Fe Model ◽  
Hole Making ◽  
Hole Geometry ◽  
Geometry Error ◽  
The Relationship ◽  
Hole Machining

Due to good aerodynamic performance and reliability, countersunk bolt joint is one of the most commonly used connection methods for carbon fiber reinforced polymer (CFRP) components in the aircraft. However, the countersunk hole machining process is inevitably accompanied by geometric errors, which will directly affect the mechanical properties of the joint structure. This paper presents a numerical and experimental investigation on the effect of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints. FE model of CFRP countersunk bolted joints with designed geometry errors are established, and the rationality of the FE analysis was verified by fatigue life and failure forms. The CFRP bolted structure failure mechanism under fatigue load and influence of hole-making geometry error (including countersunk fillets radius, countersunk depth, and countersunk angle) on the fatigue life are investigated. Based on the relationship between fatigue life and the geometry error, the corresponding tolerances for CFRP bolt joint countersunk hole are determined as well. The research results can provide a reference for establishing reasonable geometric accuracy requirements for CFRP joint hole machining.

scholarly journals Modelling of Rotary EDM Process Parameters of Inconel 718 Using Artificial Neural Networks

Mechanika ◽  
2020 ◽  
Vol 26 (6) ◽  
pp. 540-544
Author(s):  
Jayaraj JEEVAMALAR ◽  
Sundaresan RAMABALAN ◽  
Chinnamuthu SENTHILKUMAR
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Process Parameters ◽  
Inconel 718 ◽  
Machining Process ◽  
Artificial Neural ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Matlab Programming ◽  
The Relationship

Modelling is used for correlating the relationship between the input process parameters and the output responses during the machining process. To characterize real-world systems of considerable complexity, an Artificial Neural Network (ANN) model is regularly used to replace the mathematical approximation of the relationship. This paper explains the methodological procedure and the outcome of the ANN modeling process for Electrical Discharge Drilling of Inconel 718 superalloy and hollow tubular copper as tool electrode. The most important process parameters in this work are peak current, pulse on time and pulse off time with machining performances of material removal rate and surface roughness. The experiments were performed by L20 Orthogonal Array. In such conditions, an Artificial Neural Network model is developed using MATLAB programming on the Feed Forward Back Propagation technique was used to predict the responses. The experimental data were separated into three parts to train, test the network and validate the model. The developed model has been confirmed experimentally for training and testing in considering the number of iterations and mean square error convergence criteria. The developed model results are to approximate the responses fairly exactly. The model has the mean correlation coefficient of 0.96558. Results revealed that the proposed model can be used for the prediction of the complex EDM drilling process.

Automatic Recognition of Multi-Axis Machining Features Based on Machining Process from 3D Solid Model

2015 ◽  
Vol 789-790 ◽  
pp. 873-877 ◽  
Author(s):  
Phung Xuan Lan ◽  
Hoang Vinh Sinh
Keyword(s):  
Automatic Recognition ◽  
Machining Process ◽  
Solid Model ◽  
Machining Features ◽  
Rule Based ◽  
Machining Feature ◽  
Complex Design ◽  
3D Solid ◽  
The Relationship

This paper presents an effective rule-based method for extracting and recognizing the machining features from 3D solid model. The machining feature is automatically recognized while considering the relationship between machining feature and machining process. This proposed method is capable of recognizing not only prismatic machining features but also multi-axis machining features from many kinds of complex design features in both protrusion and depression. It also succeeds in recognizing various types of interaction in a uniform way. The capability of the proposed method is demonstrated in one specific case study.

The Effect of Prior Cutting Conditions on the Shear Mechanics of Orthogonal Machining

1998 ◽  
Vol 120 (1) ◽  
pp. 13-20 ◽  
Author(s):  
R. Stevenson ◽  
D. A. Stephenson
Keyword(s):  
Material Properties ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Rake Angle ◽  
Cnc Machining ◽  
Machining Process ◽  
Depth Of Cut ◽  
Prior History ◽  
Machining Conditions ◽  
The Difference

It has been proposed several times in the metal-cutting literature that the machining process is non-unique and that the instantaneous machining conditions depend on the prior machining conditions (e.g. depth of cut, rake angle etc.). To evaluate the validity of this concept, a series of experiments was conducted using a highly accurate CNC machining center. For these experiments, the machining conditions were changed during the course of an orthogonal cutting experiment in a repeatable manner and the measured forces compared as a function of prior history. Tests were conducted on several tempers of 1100 aluminum and commercial purity zinc to evaluate the effect of material properties on the machining response. It was found that the change in measured cutting forces which could be ascribed to prior machining history was less than 3 percent and that material properties, particularly work hardening response, had no discernible effect on the magnitude of the difference.

Fit Quality Evaluation and Fit Capability Analysis

1999 ◽  
Author(s):  
Y. Zhang ◽  
X. Daniel Fang
Keyword(s):  
Process Monitoring ◽  
Process Design ◽  
Quality Evaluation ◽  
Process Capability Indices ◽  
Analysis Method ◽  
Evaluation Measures ◽  
Capability Indices ◽  
Capability Analysis ◽  
The Relationship

Abstract A new measure for evaluating fit quality of mating parts via Fit Capability Indices (FCIs) is introduced as an interface between fit quality and process control of the mating parts. Fit Capability Analysis method is discussed based on the relationship between FCIs and Process Capability Indices (PCIs). A new statistical tolerancing approach for assuring predetermined fit quality is developed on the basis of fit quality evaluation measures and fit capability analysis, which can be used as a guideline to process design and process monitoring of the mating parts.

Contribution to Computer Control and Optimization of Hydro-Abrasive Jet Machining Process

1991 ◽  
Author(s):  
Roberto Groppetti ◽  
Giuseppe Comi
Keyword(s):  
Real Time ◽  
Process Model ◽  
Wide Spectrum ◽  
Computer Control ◽  
Process Condition ◽  
Machining Process ◽  
Process Variables ◽  
Real Time Control ◽  
Machining Conditions ◽  
Abrasive Jet Machining

Abstract Hydro-Abrasive Jet Machining (HAJM) has demonstrated its suitability for several applications in the machining of a wide spectrum of materials (metals, polymers, ceramics, fibre reinforced composites, etc.). The paper is a contribution to the computer control, integration and optimization of HAJM process in order to establish a hierarchical control architecture and a platform for the implementation of a real-time Adaptive Control Optimization (ACO) module. The paper presents the approach followed and the main results obtained during the development and implementation of a HAJM cell and its computerized controller. A critical analysis of the process variables available in the literature is presented, in order to identify the process variables and to define a process model suitable for HAJM real-time control and optimization. Besides for HAJM computer control, in order to correlate process variables and parameters with machining results, a process model and an optimization procedure are necessary in order to avoid expensive and time-consuming experiments for the determination of optimal machining conditions. The paper presents the configuration of the cell and the specific components adopted in order to make possible a fully computerized control of the process, and the architecture of the controller, capable to manage the several logical and analogical signals from the different modules of the cell, for multiprogramming, process monitoring, controlling, process parameters predetermination, process condition multiobjective optimization. A prediction and an optimization model is presented allowing the identification of optimal machining conditions using multiobjective programming. This model is based on the definition of an economy function and a productivity function, with suitable constraints relevant to the required machining quality, the required kerfing depth and the available resources. A test case based on experimental results is discussed in order to validate the model.

Study on Surface Integrity of PTFE Finished by Ultra-Precision Cutting and Surface Performance

2005 ◽  
Vol 291-292 ◽  
pp. 475-482 ◽  
Author(s):  
Koichi Okuda ◽  
Masayuki Nunobiki
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Cutting Force ◽  
Surface Integrity ◽  
Water Repellency ◽  
Diamond Cutting ◽  
Finished Surface ◽  
Ultra Precision ◽  
Surface Performance ◽  
The Relationship

This study aims at clarifying the relationship between the surface integrity of PTFE finished by an ultra-precision diamond cutting and the adhesion strength of a metal thin film. As the first step of this study, the basic properties such as surface integrity in the diamond cutting of PTFE and the effect of the surface roughness on the textile water repellency are demonstrated in this report. The following remarks were found. The measured roughness of finished surface largely exceeded the theoretical roughness, while the cutting force was very small comparing with aluminum and the flow type chips were formed. The surface with a smaller roughness tended to repel water.

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