Multi-Variant Simulation of Milling of 3-D Shaped Detail Considering Changing of Workpiece Rigidity While Cutting

2014 ◽  
Author(s):  
Igor Kiselev ◽  
Sergey Voronov ◽  
Sergey Arshinov
Keyword(s):  
Dynamic Characteristics ◽  
Tool Path ◽  
Surface Shape ◽  
Dynamic Parameters ◽  
Machined Surface ◽  
Model Application ◽  
Regeneration Mechanism ◽  
Process Behavior ◽  
Milling Dynamics ◽  
Stock Removal

The examples of multi-variant simulation of 5-axis milling dynamics while the machining of 3-D shaped detail in the paper are presented. The simulation model takes into account tool and detail vibrations. The regeneration mechanism is embedded into the model. The diagram of tool speed influence on the vibration amplitudes and cutting forces magnitudes for the different area of the tool path are determined. The system dynamic parameters and the vibrations behavior and their effect on the machined surface shape for favourable and unwanted regimes are analyzed. The effect of the dynamic characteristics alteration of the workpiece while stock removal on the process behavior is considered. Some recommendations for the efficient cutting conditions setting on the base of the model application and the obtained results in the conclusion are discussed.

Videooptical Surface Shape and Integrity Estimation in Robots Machining

2013 ◽  
Vol 332 ◽  
pp. 270-275 ◽  
Author(s):  
Tadeusz Mikolajczyk
Keyword(s):  
Surface Roughness ◽  
Industrial Robot ◽  
Surface Shape ◽  
Engineering System ◽  
Machined Surface ◽  
Reflectivity Method ◽  
Machining System ◽  
Grinding Tool ◽  
Smart Machining ◽  
Usb Camera

Paper shows system to surface shape and quality control in machining using industrial robot. To surface control videooptical methods were used. Surface shape was controlled using the special reverse engineering system. To surface roughness measure machined surface reflectivity method was used. Used own constructions non contact system was equipped with red laser light and USB camera. Wrist of robot was equipped with grinding tool. In paper shows some algorithms of presented processes. Shown too examples of experiments results in surface roughness measure in start end of grinding process. First trials of presented system shows possibility to build smart machining system for finishing of surface with unknown shape.

scholarly journals 5-Axis Flank Milling Tool Path Smoothing Based on Kinematical Behaviour Analysis

2011 ◽  
Vol 223 ◽  
pp. 691-700 ◽  
Author(s):  
Xavier Beudaert ◽  
Pierre Yves Pechard ◽  
Christophe Tournier
Keyword(s):  
Tool Path ◽  
Maximum Velocity ◽  
Flank Milling ◽  
Machining Time ◽  
Machined Surface ◽  
Tool Paths ◽  
Area Of Interest ◽  
Milling Tool ◽  
Joint Coordinates ◽  
Kinematical Behaviour

In the context of 5-axis flank milling, the machining of non-developable ruled surfaces may lead to complex tool paths to minimize undercut and overcut. The curvature characteristics of these tool paths generate slowdowns affecting the machining time and the quality of the machined surface. The tool path has to be as smooth as possible while respecting the maximum allowed tolerance. In this paper, an iterative approach is proposed to smooth an initial tool path. An indicator of the maximum feedrate is computed using the kinematical constraints of the considered machine tool, especially the maximum velocity, acceleration and jerk. Then, joint coordinates of the tool path are locally smoothed in order to raise the effective feedrate in the area of interest. Machining simulation based on a N-buffer algorithm is used to control undercut and overcut. This method has been tested in flank milling of an impeller and can be applied in 3 to 5-axis machining.

Surface Integrity Studies in Ball End Milling of Thin Shaped Cantilever Inconel 718

2014 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Raju S. Pawade
Keyword(s):  
Surface Integrity ◽  
Inconel 718 ◽  
Tool Path ◽  
Surface Defects ◽  
End Milling ◽  
Surface Region ◽  
Lower Surface ◽  
Machined Surface ◽  
Ball End Milling ◽  
Integrity Analysis

The paper presents the surface integrity analysis in ball end milling of thin shaped cantilever plate of Inconel 718. It is noticed that the workpiece deflection has significantly contributed to machined surface integrity in terms of surface topography and subsurface microhardness. The ball end milling performed with 15° workpiece inclination with horizontal tool path produced higher surface integrity which varies with the location of machined surface region. In general, the mid portion of the machined plate shows lower surface roughness and microhardness with less surface defects.

Multi-Scale Surface Characterization and Control Based High Density Measurements

2014 ◽  
Author(s):  
Xin Weng ◽  
Xiaoning Jin ◽  
Jun Ni
Keyword(s):  
Surface Quality ◽  
Process Monitoring ◽  
Surface Characterization ◽  
Quality Evaluation ◽  
Surface Shape ◽  
Machined Surface ◽  
Multi Scale ◽  
And Control ◽  
Scale Surface ◽  
Machined Surfaces

It is widely observed that today’s engineering products demand increasingly strict tolerances. The shape of a machined surface plays a critical role to the desired functionality of a product. Even a small error can be the difference between a successful product launch and a major delay. Thus, it is important to develop measurement tools to ensure the quality and accuracy of products’ machined surfaces. The key to assessing the quality is robust measurement and inspection techniques combined with advanced analysis. However, conventional Geometrical Dimensioning and Tolerancing (GD&T) such as flatness falls short of characterizing the surface shape. With the advancements in metrology methodology utilizing digital holographic interferometry, large amount of surface data can be captured at high resolution and accuracy without changing platform or technique. This captured High Definition Data (HDD) enables the mining of more valuable information from machined surfaces that most current industry practice cannot achieve in a timely manner. Such new metrology system opens the torrent of observable events at plant floor and increases the transparency of machining processes. This presents great opportunities to characterize machined surface into a new level of details, which can be applied in production quality evaluation and process condition monitoring and control. This research work proposes a framework of a multi-scale surface characterization for surface quality evaluation and process monitoring. Case studies are presented to show how proposed metrics could be applied in surface quality evaluation and process monitoring.

Synthesis of Cutting Tool Placement, Orientation and Motion Based on Surface Analysis

2000 ◽  
Author(s):  
C. G. Jensen ◽  
J. K. Hill ◽  
K. A. White
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
A Priori ◽  
Cutting Tools ◽  
Detection Algorithm ◽  
Detection Methods ◽  
Machined Surface ◽  
Mathematical Basis ◽  
Five Axis ◽  
Verification Techniques

Abstract Engineers and designers use a wide variety of curve and surface formulations to describe products. The process of producing the physical shape of these products has remained essentially unchanged for many years. Traditionally, the process of finish surface machining has been error prone and inefficient due in large part to the mathematical basis used to control the positioning, orientation and movement of cutting tools in five-axis machining centers. This paper presents swept silhouette curvature matching algorithms for positioning and orienting a cutter such that tool and surface curvatures match. Formulations are given for both flat and filleted end mill cutters. The benefits of curvature matching are: reduction of local machining errors, reduction or elimination of grinding of the finished machined surface, and the improvement of machine tool efficiency. Examples are given that compare curvature matching to traditional machining methods. The paper concludes by discussing current research into a priori gouge detection methods based on intersection contact between the cutting tool and the design surface or the lower tolerance-bound offset surface to the design surface. An a priori gouge detection algorithm is necessary for the development of optimal tool motion and the reduction of time spent in tool path editing and verification. Techniques involving collinear normals, Bézier clipping, triangulation, normal intersection and swept volumes are suggested as techniques for examining the positional and translational tool gouge problem.

Tool Path Generation Based on B-Spline Wavelets

2001 ◽  
Author(s):  
Ranga Narayanaswami ◽  
Junhua Pang
Keyword(s):  
Tool Path ◽  
Fundamental Problem ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Algebraic Complexity ◽  
Path Generation ◽  
Object Boundary ◽  
Machined Surface ◽  
Novel Approach ◽  
Offset Curves

Abstract Tool path generation is a fundamental problem in numerical control machining. Typical methods used for machining 2.5D objects include generation of offset contours using trimmed offset curves and zigzag sequences. The offset contours result in unnecessary detailed curves far away from the object boundary. The zigzag sequences result in frequent stops and changes in tool direction. In this paper we present a novel approach for tool path generation based on wavelet theory. The theory of wavelets naturally leads to a simple cut sequence algorithm that provides valid and efficient coverage of the machined surface. The classical analytical and algebraic complexity in tool path planning is also reduced. In this paper, curves are represented by endpoint interpolating B-splines and their corresponding wavelets. Design and manufacturing examples are also presented in this paper.

A New One-Side Finish Machining Method for Profile of Globoidal Indexing Cam in High Speed

2009 ◽  
Vol 626-627 ◽  
pp. 611-616
Author(s):  
X.F. Tang ◽  
Wei He ◽  
Y.S. Liu
Keyword(s):  
High Speed ◽  
Tool Path ◽  
New Method ◽  
Practical Calculation ◽  
Machined Surface ◽  
Finish Machining ◽  
Cam Mechanism ◽  
Cad Cam ◽  
Meshing Characteristics ◽  
Path Modification

A new one-side finish machining method for the profile of globoidal indexing cam in high speed, which modifies the tool path of traditional enveloping method, was put forward. The new method is useful for overcoming the defects caused by traditional enveloping method, can realize one-side machining of globoidal indexing cam, can improve the machined surface quality and the meshing characteristics of the cam mechanism. The practical calculation formulas of tool path modification is given, which can be used in developing the CAD/CAM software of the globoidal indexing cam. The new method has great practical value.

Studies on the Algorithm for Five-Axis NC Machining with Triangular Facet Model

2013 ◽  
Vol 385-386 ◽  
pp. 726-730
Author(s):  
Ren Xian Geng ◽  
Hou Jun Qi ◽  
Xin Pan ◽  
Zhi Gang Liu
Keyword(s):  
Tool Path ◽  
Nc Machining ◽  
Surface Shape ◽  
Free Form ◽  
Cutting Efficiency ◽  
Triangular Facet ◽  
Constant Scallop Height ◽  
Free Form Surface ◽  
Five Axis ◽  
Facet Model

Using five-axis equipment for NC machining of free-form surface is an effective way to improve machining quality and machining efficiency, the surface shape and the five coordinate of the complexity of the machine tool movement led to its tool path planning technology is difficult. The paper aimed at the five coordinate NC machining of free-form surface and puts forward a five-axis NC machining method based on triangular facet model. The research based on triangular facet model, using constant scallop height method to calculate the step distance and improve the cutting efficiency to a great extent. In the process, tool path is generated, combining with the method of configuration space interference free.

Methodic of Rational Cutting Conditions Determination for 3-D Shaped Detail Milling Based on the Process Numerical Simulation

2014 ◽  
Author(s):  
Igor Kiselev ◽  
Sergey Voronov
Keyword(s):  
Cutting Forces ◽  
Complex Geometry ◽  
Chip Thickness ◽  
Cutting Conditions ◽  
Dynamical Model ◽  
Processing Route ◽  
Technological Parameters ◽  
Machined Surface ◽  
Geometry Modeling ◽  
Milling Dynamics

The paper is devoted for the analysis of the dynamics effect on the 5-axis milling process of flexible details. The integrated model of milling dynamics composed by block principle in the paper is presented. The model consist of: 1) dynamical model of tool; 2) dynamical model of machined detail based on Finite Element Method (FEM); 3) phenomenological model of cutting forces and 4) algorithm of geometry modeling for instant machined chip thickness calculation. Regeneration mechanism of cutting and calculation of the machined surface are into this algorithm embedded. The elaborated model is adapted for 5-axis processing of the profiled details with 3-D complex geometry. Alteration of workpiece dynamic characteristics while the allowance removal is considered by the special algorithm of FEM grid changing based on the results of cutting geometry modeling. The results of modeling give us opportunity determine cutting forces, estimate the machined surface quality, calculate the magnitude and the character of tool and detail vibrations under the specified cutting conditions. The conception of increasing the process quality and the machinability for 3-D shaped details machining is offered in the paper. Applying the specified efficient conditions the undesired dynamical effects can be excluded on the base of the results of multi-variant simulation for milling dynamics varying the technological parameters at the different region of the processing route.

Understanding High Temperature Static and Dynamic Characteristics of 1.2 kV SiC Power MOSFETs

2017 ◽  
Vol 897 ◽  
pp. 501-504 ◽  
Author(s):  
Si Yang Liu ◽  
Yi Fan Jiang ◽  
Woong Je Sung ◽  
Xiao Qing Song ◽  
B. Jayant Baliga ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Dynamic Characteristics ◽  
Analytical Models ◽  
Harsh Environments ◽  
Device Physics ◽  
Dynamic Parameters ◽  
Power Mosfets ◽  
Static And Dynamic Characteristics ◽  
Temperature Capability

High temperature capability of silicon carbide (SiC) power MOSFETs is becoming more important as power electronics faces wider applications in harsh environments. In this paper, comprehensive static and dynamic parameters of 1.2 kV SiC MOSFETs have been measured up to 250°C. The electrical behaviors with the temperature have been analyzed using the basic device physics and analytical models.

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