An Experimentally Aided Operational Virtual Prototyping to Obtain the Best Spindle Speed during Face Milling of Large-Size Structures

Abstract

The paper presents an original method concerning the problem of vibration reduction in the general case while milling large-size and geometrically complex details with the use of an innovative approach to the selection of spindle speed. A computational model is obtained by applying the so-called operational approach to identify the parameters of the workpiece modal model. Thanks to the experimental modal analysis results, modal subsystem identification was performed and reliable process data for simulation studies were obtained. Next, simulations of the milling process, for successive values of the spindle speed, are repeated until the best vibration state of the workpiece is obtained. For this purpose, the root mean square values of the time plots of vibration displacements are examined. The effectiveness of the approach proposed for reducing vibrations in the process of face milling is verified on the basis of the results of appropriate experimental investigations. The economic profitability of the implementation of the operational technique in the production practice of enterprises dealing with mechanical processing is demonstrated as well.

Adjusting the Stiffness of Supports during Milling of a Large-Size Workpiece Using the Salp Swarm Algorithm

“…When considering a face-milling process where a variable is observed in time, the thickness and the width of the cutting layer of the tool cutting edge no. l , we obtained [ 30 ]: where —cutting layer thickness at time-instant t ; —nominal cutting layer thickness at time-instant t ; for [ 38 ]; —dynamic change in cutting layer thickness; —cutting layer width at time-instant t ; —nominal cutting layer width; [ 38 ]; —dynamic change in cutting layer width at time-instant t ; —time between the same position of edge no. l -1 and edge no.…”

“…However, it must be noted that in previous works this concept was described only for small-size workpieces mounted in a single, variable stiffness holder. This is also a distinctly different approach than applied previously by authors, for example, in [ 27 , 30 , 38 ]. In the current paper, a different, original approach to solving the problem of reducing the vibration level of the tool–workpiece during milling is proposed.…”

“…where ℎ (𝑡) -cutting layer thickness at time-instant t; ℎ (𝑡)-nominal cutting layer thickness at time-instant t; ℎ (𝑡) = 𝑓 sin 𝜅 cos 𝜑 (𝑡) for 𝑓 ≪ 𝐷 [38]; ∆ℎ ( )-dynamic When considering a face-milling process where a variable is observed in time, the h l (t) thickness and the b l (t) width of the cutting layer of the tool cutting edge no. l, we obtained [30]:…”

“…where h l (t)-cutting layer thickness at time-instant t; h Dl (t)-nominal cutting layer thickness at time-instant t; h Dl (t) = f z sin κ r cos ϕ l (t) for f z D [38]; ∆h l ( )-dynamic change in cutting layer thickness; b l (t)-cutting layer width at time-instant t; b D -nominal cutting layer width; b D = a p sin κ r [38]; ∆b(t)-dynamic change in cutting layer width at time-instant t; τ l -time between the same position of edge no. l-1 and edge no.…”