A technique of experiment aided virtual prototyping to obtain the best spindle speed during face milling of large-size structures

Abstract

The paper presents an original method concerning vibration suppression problem during milling of large-size and geometrically complicated workpieces with the use of novel way of selecting the spindle speed. This consists in repetitive simulations of the cutting process for subsequent values of the spindle speed, until the best vibration state of the workpiece is reached. An appropriate method of obtaining a computational model, called a modal approach, consists in identifying the parameters of the workpiece model created using the Finite Element Method (FEM). Thanks to the results of the identification of the modal subsystem obtained by the Experimental Modal Analysis (EMA) method, it can be stated that the parameters obtained from the experiment and delivered from the computational model have been correctly determined and constitute reliable process data for the simulation tests. The Root Mean Square (RMS) values of time domain displacements are evaluated. The efficiency of the proposed approach is evidenced by chosen technique of mechatronic design, called Experiment Aided Virtual Prototyping (EAVP). The proposed method is verified on the basis of the results of the experimental research of the relevant milling process.

Estimation of structural stiffness with the use of Particle Swarm Optimization

“…For example, development of self-excited chatter vibrations during machining may be related to the correlation between spindle speed and the natural frequency of the object being manufactured. Thus, proper frequency identification is crucial for process parameters choice (Kaliński et al, 2019;Kaliński et al, 2020).…”

An Improved Method of Minimizing Tool Vibration during Boring Holes in Large-Size Structures

“…The process of boring holes in a perfectly rigid large-size workpiece mounted on a machine tool table ( Figure 1 ) using a rotating flexible boring tool ( Figure 2 ) can be considered in the convention of a non-stationary Finite Element Model (FEM) [ 4 , 32 , 33 ]. When boring holes of large diameters, the design of the tool is more complicated and cannot be modelled with a single bar.…”

“…In some extreme cases it can even lead to the destruction of the tool or workpiece. To increase the milling efficiency while maintaining the surface quality and minimizing the vibration level, parameters of the machining process should be adjusted [ 4 ].…”

A Method of Predicting The Best Conditions for Clamping a Large-Size Workpiece in Order To Reduce Vibrations in The Milling Process

“…Its value is strongly correlated with the parameters characterizing the quality of the machined surface. The higher the RMS value, the worse the geometric accuracy and surface roughness are 12 .…”

“…Due to the more complicated nature of vibrations during the large-size milling process, the recommended solution cannot be associated only with the chatter vibration phenomenon. Therefore, a dedicated approach should take into account not only the natural frequencies accompanying the identified poles of the system, but also the more important and more intense influence of harmonic frequencies of forced vibrations 12 . Nevertheless, the importance of forced vibrations in the machining of large-size workpieces has already been noticed 9 , and due to the variable thickness of chips and the discontinuous nature of the process, they always occur.…”