Methods for determining the plastic work in bending and impact of selected factors on its value

The paper describes various methods which may be used in determining the deformation energy in the plastic region of bent wood. The present work focuses on various definitions of the plastic work of wood as well as the influence of various factors on its value. Approximated plastic work and total plastic work were determined for beech (Fagus Sylvatica L.) and aspen (Populus Tremula L.) wood. We took into consideration the following factors: wood species (WS) (Fagus Sylvatica L. and Populus Tremula L.), material thickness (MT) (4, 6, 10, and 18 mm), degree of densification (DOD) (10% and 20% of the original thickness), and the number of stressing cycles (NC) (0 versus 10,000). The study brings a new quantitative expression of an approximated plastic work “AW”, and total plastic work “BW” and the values of approximation error “ΔW”, which are made due the applied approximation.