Fracture toughness and shear yield strength determination for two selected species of central European provenance

Abstract

When offcut of wood is formed by shearing, Atkins’s analyses of sawing processes can be applied. Using this modern approach, it is possible to determine the fracture toughness and shear yield strength of wood. This model is only applicable for the axial-perpendicular cutting direction because both of these parameters are suitable for the given direction of cutting edge movement and cannot be considered material constants. Alternatively, these parameters can be recalculated for the perpendicular and axial directions of cutting when the parameters are considered non-variable quantities. The set of data necessary for calculation can be easily obtained while cutting wood with common circular saw blades. It is necessary to ensure a minimum of two levels of workpiece height and two diverse levels of feed speed. The main aim was to develop an alternative methodology for simultaneous determination of wood fracture toughness and shear yield strength for two principal directions regarding wood grains on the basis of cutting tests performed during circular saw blade cutting for two selected wood species of Central Europe provenance, such as spruce (Picea abies (L.) Karst.) and beech (Fagus sylvatica L.).

Revisiting the estimation of cutting power with different energetic methods while sawing soft and hard woods on the circular sawing machine: a Central European case

“…The newly developed cutting model (FRAC_MOD), which includes plasticity and friction, and where work of separation is not omitted in the model, is capable of forecasting not only average values of cutting power but also its dynamical changes . In the FRAC_MOD, it was assumed that cutting force F c , acting in the middle of the cutting edge, is an equilibrium of forces related to the direction of primary motion for a single saw tooth, and the mechanical process of material separation from the sawn workpiece, i.e., chip formation, can be approximately described by the example of an orthogonal process (two-dimensional deformation) (Orlowski et al , 2014Orlowski and Ochrymiuk 2013;Hlásková et al 2015Hlásková et al , 2018.…”

“…Fig. 5 The circular saw blade tooth geometry in the tool-inhand system: α f the tool side flank, α′ p the tool back flank, κ r tool cutting edge angle, κ′ r minor tool cutting edge angle, γ f the tool side rake, λ s the cutting edge inclination angle -for pine wood in the industrial conditions at the Complex Sawmill in Dziemiany (Poland); • Hlásková et al (2018)-for beech wood at the laboratory stand, which has the same kinematic system as a circular sawing machine.…”

Reducing the Energy Consumption of Circular Saws in the Cutting Process of Plywood

“…and a combination of factors. The effect of these factors on energy consumption has been investigated by several authors [7][8][9][10][11][12][13][14][15]. When using circular saws, the corrugation of the machined surface is affected by cutting parameters such as cutting height and feed speed.…”

Influence of Circular Saw Blade Design on Reducing Energy Consumption of a Circular Saw in the Cutting Process

“…), and a combination of factors. The effect of these factors has been investigated on energy consumption by the authors of [15][16][17][18][19][20][21][22][23]. When using circular saws, the waviness of the machined surface is affected by cutting parameters such as cutting height and feed speed.…”