Mechanistic Model of Work-Piece Diametrical Error in Conventional and Ultrasonic Assisted Turning

2012 ◽  
Vol 445 ◽  
pp. 911-916 ◽  
Author(s):  
H. Soleimanimehr ◽  
Mohammad Javad Nategh ◽  
H. Jamshidi
Keyword(s):  
Analytical Model ◽  
Elastic Deformation ◽  
Mechanistic Model ◽  
Experimental Results ◽  
Work Piece ◽  
Force Model ◽  
Deformation Model ◽  
Spring Back ◽  
Ultrasonic Assisted ◽  
Elastic Spring

The spring back is a major source of diametrical error occurring in turning of workpieces. In order to analyze diametrical error, an elastic deflection model of workpiece should be available. Many assumptions are usually taken into consideration when analyzing the elastic deformation of workpiece. Many studies have been done to find the analytical model of work-piece spring back and its suitable cutting force model. When compared with experimental data, developed models in these works are associated with considerable errors. In this paper, through using experimental results, an efficient elastic deformation model of workpiece has been obtained which can be compared with analytical model. Many experiments were performed, and some different functions were produced which predict the trend of experimental results. Finally, an appropriate model with the lowest error was suggested. The same process has been performed in ultrasonic vibrations assisted turning. The obtained functions will be suitable to compensate for the diametrical error occurring by machining forces. Finally this model has been used to obtain the amount of elastic spring back of tool and spindle.

Analytical Modeling of Machining Forces and Friction Characteristics in Ultrasonic Assisted Turning Process

2021 ◽  
pp. 1-13
Author(s):  
Jay Airao ◽  
Chandrakant Kumar Nirala
Keyword(s):  
Analytical Model ◽  
Work Piece ◽  
Contact Ratio ◽  
Friction Characteristics ◽  
Machining Forces ◽  
Ultrasonic Assisted ◽  
Predicted Model ◽  
Ss 304 ◽  
Intermittent Cutting ◽  
Conventional Machining

Abstract Intermittent cutting characteristics of Ultrasonic assisted turning (UAT), Compared to conventional turning (CT), has shown a significant enhancement in the machinability of hard-to-cut materials. The enhancement in machinability is associated with machining forces and friction characteristics of the process. The present article covers an analytical approach to predict the output responses such as machining forces and friction characteristics in UAT and CT processes. Specific cutting energy (SCE) for a particular work-piece material was considered to predict the output responses. The predictions were made by considering the conventional machining theories. Experiments for the UAT and the CT of SS 304 were carried out to validate the predicted model. The results from the analytical model showed that the shear angle increases and the tool-workpiece contact ratio (TWCR) decrease with an increase in amplitude and frequency of vibration. The results obtained from the analytical model were found to be in close agreement with the experimental ones, with an approximate error of 2-20%.

scholarly journals Wear-dependent specific coefficients in a mechanistic model for turning of nickel-based superalloy with ceramic tools

2017 ◽  
Vol 7 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Luis Norberto López de Lacalle ◽  
Gorka Urbicain Pelayo ◽  
Asier Fernández-Valdivielso ◽  
Alvaro Alvarez ◽  
Haizea González
Keyword(s):  
Cutting Force ◽  
Mechanistic Model ◽  
High Strength ◽  
Work Piece ◽  
Force Model ◽  
Cutting Force Model ◽  
Ceramic Tools ◽  
Nickel Based Superalloy ◽  
Force Relation ◽  
Tool Replacement

AbstractDifficult to cut materials such as nickel and titanium alloys are used in the aeronautical industry, the former alloys due to its heat-resistant behavior and the latter for the low weight - high strength ratio. Ceramic tools made out alumina with reinforce SiC whiskers are a choice in turning for roughing and semifinishing workpiece stages. Wear rate is high in the machining of these alloys, and consequently cutting forces tends to increase along one operation.This paper establishes the cutting force relation between work-piece and tool in the turning of such difficult-to-cut alloys by means of a mechanistic cutting force model that considers the tool wear effect. The cutting force model demonstrates the force sensitivity to the cutting engagement parameters (ap, f) when using ceramic inserts and wear is considered.Wear is introduced through a cutting time factor, being useful in real conditions taking into account that wear quickly appears in alloys machining. A good accuracy in the cutting force model coefficients is the key issue for an accurate prediction of turning forces, which could be used as criteria for tool replacement or as input for chatter or other models.

Mechanistic Model of Work-Piece Diametrical Error in Conventional and Ultrasonic Assisted Turning

2012 ◽  
Vol 445 ◽  
pp. 911-916
Author(s):  
H. Soleimanimehr ◽  
Mohammad Javad Nategh ◽  
H. Jamshidi
Keyword(s):  
Mechanistic Model ◽  
Work Piece ◽  
Ultrasonic Assisted

Mechanistic Based Cutting Force Model During Ultrasonic Assisted Turning with Self-Lubricating Cutting Inserts

2019 ◽  
Vol 18 (01) ◽  
pp. 133-155 ◽  
Author(s):  
Varun Sharma ◽  
Pulak M. Pandey
Keyword(s):  
Cutting Forces ◽  
Mechanistic Model ◽  
Percentage Error ◽  
Force Model ◽  
Average Force ◽  
Free Body Diagram ◽  
Ultrasonic Assisted ◽  
Cutting Insert ◽  
Cutting Inserts ◽  
On Chip

The present research paper presents a mechanistic model for determining the cutting forces during Ultrasonic Assisted Turning (UAT) process using self-lubricating textured cutting inserts. In order to understand the mechanics of the process, forces on chip have been analyzed by using free body diagram. The force and momentum equilibrium on chip have been used to define the governing force equations. The effect of ultrasonic vibrations has been considered by taking the average force of cutting over a complete cycle of vibration. The self-lubricating cutting insert has been modeled to study the effect of intermittent cutting and thin lubricating layer formation at tool-chip interface. The validation of the developed model has been done by performing UAT experiments with self-lubricating textured cutting inserts. It is observed that percentage error of prediction by mechanistic model in determining main and radial components of cutting forces is of the order of 6.73% and 14.67%, respectively with respect to the experimental values.

scholarly journals Analysis of the Vertical Stiffness of Rolling Guide that Involves the Elastic Deformation of Carriage Skirt

2015 ◽  
Vol 9 (1) ◽  
pp. 726-732 ◽  
Author(s):  
Li Jinfeng ◽  
Wang Liping ◽  
Guan Liwen
Keyword(s):  
Elastic Deformation ◽  
Calculation Method ◽  
Numerical Results ◽  
Experimental Results ◽  
Cnc Machine Tools ◽  
Deformation Model ◽  
Static Stiffness ◽  
Important Indicator ◽  
Vertical Stiffness ◽  
Rolling Guide

Static stiffness is an important indicator of the performance of a rolling guide, having direct influence on the stiffness and precision of computer numerically controlled (CNC) machine tools. After preloading the rolling guide, an outward elastic deformation is generated at the carriage skirt, which leads to a decrease in the static stiffness of the rolling guide. Therefore, there would be relatively large errors between the numerical results and the experimental results when the carriage is considered as a rigid body. In this paper, an analytical method for estimating the vertical stiffness of rolling guide was proposed, which took into account the elastic deformation in the carriage skirt. The contact elastic deformation model under loads was given using Hertz’s contact theory, from which the numerical results for the vertical stiffness of the surface of the rolling guide was calculated when the elastic deformation in the carriage skirt was ignored. The calculation method for the carriage skirt deformation was given using the finite element method, from which the numerical relationship between the deformation and the contact force was obtained after fitting adjustment. An analytical model was therefore established and took into account the elastic contact deformation and the carriage skirt deformation, and a universal calculation method was proposed for vertical stiffness. Experimental results show that compared to those not involving the deformation, the numerical results for vertical stiffness involving the carriage skirt deformation matched more closely with the experimental results, with relative errors no greater than 6.5%.

scholarly journals Generalized analytical model based on harmonic coupling for hybrid plasmonic modes: comparison with numerical and experimental results

2015 ◽  
Vol 23 (21) ◽  
pp. 27376 ◽  
Author(s):  
Mitradeep Sarkar ◽  
Jean-François Bryche ◽  
Julien Moreau ◽  
Mondher Besbes ◽  
Grégory Barbillon ◽  
...  
Keyword(s):  
Analytical Model ◽  
Experimental Results ◽  
Model Based

A novel model of Z-pin insertion in prepreg based on fracture mechanics

2021 ◽  
pp. 095440542110144
Author(s):  
Guobiao Ji ◽  
Liang Cheng ◽  
Shaohua Fei ◽  
Jiangxiong Li ◽  
Yinglin Ke
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Analytical Model ◽  
Model Parameters ◽  
Force Model ◽  
Fe Model ◽  
Cohesive Elements ◽  
Fe Method ◽  
Insertion Force ◽  
Mechanics Model

Through-thickness reinforcement is a promising solution to the problem of delamination susceptibility in laminated composites. Modeling Z-pin–prepreg interaction is essential for accurate robotics-assisted Z-pin insertion. In this paper, a novel Z-pin insertion force model combining the classical cohesive finite element (FE) method with a dynamic analytical fracture mechanics model is proposed. The velocity-dependent cohesive elements, in which the fracture toughness is provided by the analytical model, are implemented in Z-pin insertion FE model to predict the crack initiation and propagation. Then Z-pin insertion experiments are performed on prepreg sample with metallic Z-pins at different velocities to identify the analytical model parameters and validate the simulation predictions offered by the model. Dynamics of Z-pin interaction with inhomogeneous prepreg is described and the effects of insertion velocity on prepreg contact force are studied. Results show that the force model agrees well with experiments and the fracture toughness rises with the increasing Z-pin insertion velocity.

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

Optimization Design of Drawbead in Drawing Tools of Autobody Cover Panel

2002 ◽  
Vol 124 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Gang Liu ◽  
Zhongqin Lin ◽  
Youxia Bao
Keyword(s):  
Optimization Algorithm ◽  
Optimization Design ◽  
Design Method ◽  
Experimental Results ◽  
Hybrid Optimization ◽  
Force Model ◽  
Hybrid Optimization Algorithm ◽  
Design Plan ◽  
Formed Part ◽  
Restraining Force

In the tooling design of autobody cover panels, design of drawbead will affect the distribution of drawing restraining force along mouth of dies and the relative flowing velocity of the blank, and consequently, will affect the distributions of strain and thickness in a formed part. Therefore, reasonable design of drawbead is the key point of cover panels’ forming quality. An optimization design method of drawbead, using one improved hybrid optimization algorithm combined with FEM software, is proposed in this paper. First, we used this method to design the distribution of drawbead restraining force along the mouth of a die, then the actual type and geometrical parameters of drawbead could be obtained according to an improved drawbead restraining force model and the improved hybrid optimization algorithm. This optimization method of drawbead was used in designing drawing tools of an actual autobody cover panel, and an optimized drawbead design plan has been obtained, by which deformation redundancy was increased from 0% under uniform drawbead control to 10%. Plastic strain of all area of formed part was larger than 2% and the minimum flange width was larger than 10 mm. Therefore, not only better formability and high dent resistance were obtained, but also fine cutting contour line and high assembly quality could be obtained. An actual drawing part has been formed using the optimized drawbead, and the experimental results were compared with the simulating results in order to verify the validity of the optimized design plan. Good agreement of thickness on critical areas between experimental results and simulation results proves that the optimization design method of drawbead could be successfully applied in designing actual tools of autobody cover panels.

A Mechanistic Force Model of the 5-Axis Milling Process

2000 ◽  
Author(s):  
Paul A. Clayton ◽  
Mohamed A. Elbestawi ◽  
Tahany El-Wardany ◽  
Dan Viens
Keyword(s):  
High Speed ◽  
Mechanistic Model ◽  
Back Propagation ◽  
High Speed Steel ◽  
Cutting Edge ◽  
Analytic Description ◽  
Force Model ◽  
Force Output ◽  
Five Axis ◽  
Milling Force Model

Abstract This paper presents a five-axis milling force model that can incorporate a variety of cutters and workpiece materials. The mechanistic model uses a discretized cutting edge to calculate an area of intersection which is multiplied by the specific cutting pressure to produce a force output along the primary cartesian coordinate system. By using an analytic description of the cutting edge with a non-specific cutter and workpiece intersection routine, a model was created that can describe a variety of cutting situations. Furthermore, a back propagation neural network is used to calibrate the model, providing robustness and scalability to the calibration process. Testing was performed on 1020 steel using various cutting parameters with a high speed steel two flute cutter and a tungsten carbide insert cutter. Furthermore, both linear cuts and a test die surface yielded good agreement between predicted and measured results.

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