Cutting Test as Source of Fracture Toughness and Shear Yield Strength for Axial-Perpendicular Model of Wood Cutting

Hlásková, Luďka; Kopecký, Zdeněk; Solař, Aleš; Patočka, Zdeněk

doi:10.22382/wfs-2019-006

Cited by 8 publications

(5 citation statements)

References 19 publications

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“…An independent variable of the regression is the uncut chip thickness h. It has become possible, therefore, to determine values of fracture toughness R ⊥ and shear yield stress τ γ ⊥ by matching the regression Equation (8) with the experimental data from the cutting tests. A similar approach was reported for diverse materials and cutting kinematics [ 40 , 46 , 51 ]. However, in the case of the frame sawing process investigated here, values of both fracture toughness R ⊥ and shear yield stresses τ γ ⊥ are determined for cutting perpendicular to wood fibers direction Φ G–vc (case 90−90 according to Kivimaa [ 52 ]).…”

Section: Methodsmentioning

confidence: 91%

Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress

et al. 2020

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The modern wood converting processes consists of several stages and material drying belongs to the most influencing future performances of products. The procedure of drying wood is usually realized between subsequent sawing operations, affecting significantly cutting conditions and general properties of material. An alternative methodology for determination of mechanical properties (fracture toughness and shear yield stress) based on cutting process analysis is presented here. Two wood species (pine and beech) representing soft and hard woods were investigated with respect to four diverse drying methods used in industry. Fracture toughness and shear yield stress were determined directly from the cutting power signal that was recorded while frame sawing. An original procedure for compensation of the wood density variation is proposed to generalize mechanical properties of wood and allow direct comparison between species and drying methods. Noticeable differences of fracture toughness and shear yield stress values were found among all drying techniques and for both species, but only for beech wood the differences were statistically significant. These observations provide a new highlight on the understanding of the effect of thermo-hydro modification of wood on mechanical performance of structures. It can be also highly useful to optimize woodworking machines by properly adjusting cutting power requirements.

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Section: Methodsmentioning

confidence: 91%

Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress

et al. 2020

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“…A review of the literature shows that the effect of cutting condition on the magnitudes of cutting forces, surface quality and chip formation are the main subjects of cutting studies. Forces acting on the workpiece and the tool in wood machining processes have been extensively investigated both theoretically and experimentally [ 1 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Nevertheless, none of these studies have examined the effect of the feed force, even though this is one of the most available parameters of the cutting process—easily sensed by the operator’s hand.…”

Section: Introductionmentioning

confidence: 99%

Feed Force and Sawdust Geometry in Particleboard Sawing

et al. 2021

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The measurement of cutting forces permits building of physic-mechanical cutting models for a better understanding of the phenomena observed during cutting. It also permits the design and optimization of processes, machines, tools, and wood preparation. Optimization of cutting conditions of wood-based materials can decrease the cutting forces, which directly relates to the energy consumption and surface quality. The sawdust analysis may serve for analysis of cutting kinematics and occupational health risk. The aim of the study was to estimate the correlation between the feed rate and both feed force and sawdust particle size produced during particleboard circular sawing. A saw machine type K700 was used in experiments. There were three feed rates of 12, 18, and 24 m/min executed by a horizontal pneumatic actuator fixed to the sliding side table of the saw machine. Based on the results of the experiments, a positive correlation was observed between the feed rate in a circular sawing process and feed forces and an unexpected particle size distribution depending on the feed rate.

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“…Using the measured moment of force, M c , and the feed force, F f , other components of the resulting active force were determined. The calculation was based on the Ernst–Merchant circle force diagram [ 42 ]. The second component expresses the kinetic energy for chip removal by the circular sawblade (does not affect the value of cutting resistance).…”

Section: Methodsmentioning

confidence: 99%

Interaction between Thermal Modification Temperature of Spruce Wood and the Cutting and Fracture Parameters

et al. 2021

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This work examines the effect of thermal modification temperatures in the production of thermally modified wood on the cutting and fracture parameters when cutting heat-treated spruce wood by a circular sawblade machine. The samples were thermally modified at 160, 180, 200, and 220 °C. One sample was unmodified and was used as a reference sample. On the basis of the performed experiments, the fracture parameters (fracture toughness and shear yield strength) were calculated for the axial–perpendicular direction of cutting. In comparison with the theoretical assumptions, the influence of temperature on the cutting and fracture parameters was confirmed. Thermally treated wood is characterized by increased fragility and susceptibility to crack formation, as well as reduced density, bending strength, and shear strength. These properties significantly affect the size of the cutting force and feed force, as well as the fracture parameters. As the temperature increases, the values of these parameters decrease. The mentioned material characteristics could be useful for the optimization of the cutting process, as well as for the issue of energy consumption during the machining of heat-treated wood.

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Cutting Test as Source of Fracture Toughness and Shear Yield Strength for Axial-Perpendicular Model of Wood Cutting

Cited by 8 publications

References 19 publications

Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress

Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress

Feed Force and Sawdust Geometry in Particleboard Sawing

Interaction between Thermal Modification Temperature of Spruce Wood and the Cutting and Fracture Parameters

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