MOR and MOE of Serbian Spruce (Picea omorika Pančić/Purkyně) Wood from Natural Stands

The paper presents the results of testing the bending stress of Serbian spruce wood from natural stands. In testing the samples, in addition to the modulus of rupture, the bending stress at the proportionality limit, the ratio between the stress at the proportionality limit and the modulus of rupture as well as the modulus of elasticity of wood were determined. The study included nine trees from natural stands, and a total of 261 samples were tested. Regression analysis determined the dependences of these mechanical properties on the annual ring width, the proportion of late wood and wood density, as well as the dependence of the modulus of elasticity on the modulus of rupture. U radu su prikazani rezultati ispitivanja naprezanja pri savijanju drva Pančićeve omorike podrijetlom iz prirodnih sastojina. Osim modula loma, pri ispitivanju uzoraka utvrđeni su i savojno naprezanje u točki proporcionalnosti, odnos čvrstoće na savijanje u točki proporcionalnosti i modula loma, kao i modul elastičnosti drva. Istraživanje je obuhvatilo devet stabala iz prirodnih sastojina, a ispitan je ukupno 261 uzorak. Regresijskom su analizom utvrđeni odnosi navedenih mehaničkih svojstava i širine goda, udjela kasnog drva i gustoće drva, kao i odnos modula elastičnosti i modula loma.