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Antarvedi Goda, Bharath

University of British Columbia

Cutting mechanics of soft solids has been of growing interest due to its promising benefits in material characterization and other industrial applications. However, a full understanding of the physical phenomena is still missing, and several questions remain outstanding. In this thesis, we explore the simple problem of wire cutting. Through finite element analysis and dimensional arguments, we obtain a simple scaling relation between the wire radius and the steady-state cutting forces. We note that, in the absence of dissipative mechanisms, steady-state cutting forces are independent of blade sharpness. However, in the presence of dissipation in the form of friction and adhesion, we show that tough materials are sensitive to friction, whereas, brittle materials are sensitive to dissipation in the form of adhesion and wear. In the regime dominated by friction, cutting forces have a weaker sensitivity to blade sharpness. But, in the regime dominated by adhesion and shear damage/ wear, we have a linear dependence between cutting force and blade sharpness. By accounting for strain-stiffening and compressibility of the soft material, we note that tough and highly strain-stiffening materials are most sensitive to frictional dissipation. Whereas, in-compressible brittle materials are most sensitive to adhesion and wear dissipation. Finally, this thesis provides important findings: Toughness can be estimated from wire-cutting experiments from the intercept of the forcewire radius linear correlation, however this only estimates cleavage toughness. In the adhesive/wear regime, a larger radius would scale the cutting fracture process zone giving rise to higher apparent toughness.

Text

2024-08-12

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/88920

Mechanical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/