Milling Dynamics

2018 ◽  
pp. 129-212
Author(s):  
Tony L. Schmitz ◽  
K. Scott Smith
Keyword(s):  
Milling Dynamics

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.

Milling Dynamics

2009 ◽  
pp. 99-171 ◽  
Author(s):  
Tony L. Schmitz ◽  
Kevin S. Smith
Keyword(s):  
Milling Dynamics

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.

Dynamics of 2-DOF Micro-End-Milling System Considering Grain-Size Variation

2013 ◽  
Vol 758 ◽  
pp. 165-173
Author(s):  
Anna Carla Araujo ◽  
Marcelo A. Savi ◽  
Pedro Manuel Calas Lopes Pacheco
Keyword(s):  
End Milling ◽  
Machining Process ◽  
Grain Structure ◽  
Homogeneous Material ◽  
Primary System ◽  
Secondary System ◽  
Inhomogeneous Materials ◽  
Tool Holder ◽  
Micro End Milling ◽  
Milling Dynamics

Non-smooth systems are employed to model different cutting processes including milling and oil drilling. This article deals with the modeling of the micro-end-milling dynamics with inhomogeneous materials. The model considers a non-smooth system composed of a primary system that represents the tool and a secondary system, representing the workpiece. This system mimics micro-end-milling dynamics considering a progressive motion of the tool holder with tool run-out. The relative position of the tool holder and the chip is evaluated avoiding huge displacements of the tool tip when the tool is not in cutting. The simplified dynamics presented in this article is used as a methodology to calculate the cutting force and tool performance from the prescribed trajectory. The inhomogeneity is related to the description of the micro-machining process where material properties cannot be considered as constant due to grain structure as the tool moves for cutting. Numerical simulations consider a situation where the grain workpiece has austenitic, ferritic or ferritic-austenitic phases. Microscopic analysis is employed to obtain the property variations. The main goal is to establish a qualitative comprehension of the system dynamics comparing results with homogeneous material cutting process.

scholarly journals Milling Dynamics and Propagation of Mechanically Activated Self-Sustaining Reactions

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Alberto Cincotti ◽  
Gabriele Traversari ◽  
Giorgio Pia ◽  
Francesco Delogu
Keyword(s):  
Reaction Rate ◽  
Equations Of Motion ◽  
Analytical Description ◽  
Chemical Conversion ◽  
Mechanical Processing ◽  
Ball Mills ◽  
Operational Conditions ◽  
Powder Particles ◽  
Milling Dynamics ◽  
Individual Particles

This work focuses on the propagation of mechanically activated self-sustaining reactions during the mechanical processing of powder in ball mills. We use a numerical model to reconstruct the dynamics of a single ball and powder particles inside the reactor of a SPEX Mixer/Mill 8000 under operational conditions. Taking advantage of the analytical description of the reactor swing, the equations of motion of ball and powder particles are solved numerically. The discrete element method is used to describe contacts. Reaction is ignited in an individual particle randomly selected among those compressed during an impact between ball and reactor. A simple kinetic law and a set of rules involving degree of chemical conversion and distance between particles are used to obtain a phenomenological description of the reaction propagation. We show that the propagation is significantly affected by reaction rate in individual particles, with other factors being less influential. We observe a strong coupling between the dynamics of powder particles and the reaction propagation.

Analysis of milling dynamics for simultaneously engaged cutting teeth

2010 ◽  
Vol 329 (5) ◽  
pp. 585-606 ◽  
Author(s):  
Oleg A. Bobrenkov ◽  
Firas A. Khasawneh ◽  
Eric A. Butcher ◽  
Brian P. Mann
Keyword(s):  
Milling Dynamics

Experimental Full Cut Milling Dynamics

CIRP Annals ◽  
1980 ◽  
Vol 29 (1) ◽  
pp. 61-66 ◽  
Author(s):  
P.E. Gugax ◽  
E. Mathias
Keyword(s):  
Milling Dynamics

Mode Coupling Behavior in End Milling

2009 ◽  
Author(s):  
C. Y. Huang ◽  
J.-J. Junz Wang
Keyword(s):  
Mode Coupling ◽  
End Milling ◽  
Milling Process ◽  
Chatter Vibration ◽  
Rotation Direction ◽  
Coupling Behavior ◽  
Structure Vibration ◽  
The Stability ◽  
Milling Dynamics ◽  
End Milling Process

Chatter is caused by two main mechanisms: the regenerative waviness and the mode coupling. Both of these two chatter mechanisms always exist simultaneously, but most studies only discuss the regenerative chatter behavior. The purpose of this paper is to investigate the mode coupling behavior in end milling process. A mechanical model considering both of the regenerative and mode coupling effects is then constructed to simulate the milling dynamics. It is shown that the stability of milling is dominated by the eigenvalues of the process matrix and the structure vibration trajectories are affected by the eigenvectors of the process matrix. The rotation direction of chatter vibration is an important feature to determine whether mode coupling chatter occurs or not. By analyzing vibration trajectories, this paper then shows that chatter vibration will rotate in the direction which periodically accumulates the vibration energy. Finally, some methods for adjusting the cutting conditions to avoid the mode coupling chatter are proposed.

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