Effect of the loading rate, angle of orientation of fibers, and temperature on the strength properties of birch

The present paper reports results of analysis of the strength and strain properties of birth wood at different loading rates, sample temperatures, and angles of orientation of fibers relative to the direction of loading. Dynamic tests ($v$ = 10 m/sec) with axial compression of the samples were conducted by the Kol'skii method on a setup with a Hopkinson compound rod. Noticeable dynamic strengthening of samples with angles of orientation of fibers $\alpha$ = 0 and 5$^\circ$ was observed. At test temperatures +65, +20, and -30$^\circ$C, the dynamic strength is higher than the quasistatic strength by approximately 23, 31, and 42% respectively.