On the multiscale tribological signatures of the tool helix angle in profile milling of woven flax fiber composites

Abstract

The present study is focused on tribological and multiscale analysis for the machined surfaces of bidirectional flax fibers reinforced polypropylene composites. This is to track the multiscale effect of the helix angle of the cutting tool, related to its kinematic, on the cutting mechanisms. The results show that the helix angle has significant effect on the tribological performances which affect the tribo-contact interaction between the flax fibers and the cutting edge. The fibers orientation in the woven reinforcement has significant effect on the surface quality. The multiscale analysis reveals the pertinent scales that activate the helix angle effect.

Mechanics of material removal when cutting natural fiber reinforced thermoplastic composites

“…from technical fiber size [∼50 μm] to fiber yarn size [∼1 mm]). This finding corresponds to the conclusions obtained by profile milling process [15][16][17]. However, for the orthogonal cutting process, it can be seen in Fig.…”

“…The uncut fiber extremities are the specific phenomena in the case of machining plant fiber composites because of the transverse flexibility issue of plant fibers when being in contact with the cutting tool as demonstrated in the previous milling operation work [15][16][17], especially when increasing the cutting edge radius [17]. Moreover, the high cutting forces induced by increasing the cutting depth ( Fig.…”

“…Standard machining processes, such as milling, are still the best suitable for machining polymeric composites since they induce low levels of damage in the machined surface [13]. For these reasons, many work was conducted by the authors in order to understand the behavior of plant fibers inside the composite during the industrial machining process of profile milling [14][15][16][17]. These studies show that, effectively, the behavior of plant fibers is different from that of synthetic fibers and this is due to their complex and multiscale cellulosic structure around the fiber axis [18].…”

New Multiscale Approach for Machining Analysis of Natural Fiber ReinforcedBio-Composites

“…The idea is to find at which range, each material/process variable affects the morphology of the machined surface. The wavelet transform can be used by a discrete wavelet transform (DWT) [32] or a continuous wavelet transform (CWT) [31]. The aim of this wavelet transform is to decompose the global topographic signal through a series of highpass and low-pass filters to analyze the high and low frequencies [34][35][36][37][38][39].…”

“…Unfortunately, the edge finishing of NFRP materials are difficult and still based on empirical rules because the multiscale activated physical mechanisms are still not well understood. This is why the previous works of the authors [29][30][31][32][33] have focused on the multiscale analysis of the machinability for the main structures of NFRP materials.…”