Determination of mode I and mode II fracture toughness of walnut and cherry in TR and RT crack propagation system by the Arcan test

Abstract

Two specimen types, each from walnut and cherry wood, were prepared for tangential-radial (TR) and radial-tangential (RT) crack propagation systems at 65% of RH and 20°C before mode I and mode II fracture toughness was determined through Arcan tests. It was found that fracture toughness in mode I is in agreement with literature data. In the mode II test, however, the crack propagated in the direction normal to the shear plane and not parallel to it. The release rate of strain energy in terms of the opening failure in mode II was lower than that in mode I. It can be concluded that it is difficult to determine the fracture toughness of RT or TR propagation in hardwood specimens in mode II.

Thermally modified (TM) beech wood: compression properties, fracture toughness and cohesive law in mode II obtained from the three-point end-notched flexure (3ENF) test

“…Tukiainen and Hughes (2016b) studied the same species at a cellular level by means of environmental electron scanning microscopy (ESEM) and DIC and found in case of dry wood that microcracking was the predominant mechanism of increased toughness, and in case of wet wood that both microcracking and plastic deformation took place. The fracture properties of cherry (Prunus avium L.) and walnut (Juglans regia L.) were observed by the Arcan test in modes I and II (Murata et al 2017), and the data from mode II were found to be more questionable due to undesired crack propagation vectors.…”

Mechanical behavior of walnut (Juglans regia L.) and cherry (Prunus avium L.) wood in tension and compression in all anatomical directions. Revisiting the tensile/compressive stiffness ratios of wood

“…Hence, a large part of historical objects found in the museums is made of these woods, which are hitherto not well characterized from the mechanical point of view. The fracture toughness of walnut and cherry were described in the perpendicular plane (Murata et al 2017). The tension and compression loadings of these woods were often carried at one MC level and mainly in the L-direction (Keylwerth 1951;Nocetti et al 2010;Korkut and Aytin 2015).…”

Mechanical properties of the most common European woods: a literature review

“…4000 MPa). The values measured in radial and tangential directions, despite being lower, follow the same trend: ET is slightly lower than ER except for Cherry (ID5 [13]), which has a value of ET = 885 MPa and a value of ER = 1069 MPa, that remains slightly greater. The MOE values in these two directions never exceed 2000 MPa.…”

“…Ash (ID2 [10]), which has an average density value of 701 kg/m 3 , has the highest average E L value of 15800 MPa. Finally, we find the Beech (ID5 [13]) that has a mean density higher than Ash (725 kg/m 3 ). However, the error scatter of Beech density is rather high, as we can see in Tab.…”