VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • Cutting force variability as a consequence of exchangeable cleavage fracture and compressive breakdown of wood tissue
    Merhar, Miran ; Bučar, Bojan, 1961-2012
    In the present study, the conditions of chip propagation or fracture in orthogonal oblique cutting of beech wood (Fagus silvatica) in the 90° direction for a type-I chip has been investigated. The ... force required for orthogonal wood cutting is pronouncedly variable, which is the consequence of exchangeable different ways of material breakdown. The chip formation process is discontinuous because of interrupted splitting of the material in front of the cutting tool. A 10-mm-thick specimen was cut at a rake angle of 31° and 42° with chip thicknesses ranging from 0.1 to 0.3 mm. The chip segment length increased with the chip thickness. A chip of varying length and thickness was modelled using the finite element method. For each case, the bending or compressive stress in the chip and the stress intensity factor at the crack tip was calculated. The segment length of the chip can be calculated by taking into account the condition that a crack propagates when the stress intensity factor K I at the crack tip equals the critical stress intensity factor K IC, and the bending or compressive stress sigma x in the chip is smaller than the strength sigm u . Good agreement between the calculated and the measured values was observed. The chip segment length can change considerably already with small changes in the bending strength and critical stress intensity factor. This large sensitivity is also confirmed by the fluctuation of the measured chip segment lengths by as much as 400%.
    Vir: Wood Science and Technology. - ISSN 0043-7719 (Vol. 46, issue 5, 2012, str. 965-977)
    Vrsta gradiva - članek, sestavni del
    Leto - 2012
    Jezik - angleški
    COBISS.SI-ID - 1989001

    Povezava(-e):

    http://www.springerlink.com/content/f6j2l58726854ru7/fulltext.pdf
    Repozitorij Univerze v Ljubljani – RUL
    DOI

vir: Wood Science and Technology. - ISSN 0043-7719 (Vol. 46, issue 5, 2012, str. 965-977)
loading ...
loading ...
loading ...

Vnos na polico