Development of Mathematical Model for Predicting the Cupping of Lumber

Abstract

Deformations are a significant disadvantage of wood as a structural material for products made of it. Therefore, the purpose of this work was to determine the magnitude and nature of the deformations of lumber used for the manufacturing of laminated panels in construction. The main causes of the possible changes in the shape of the surfaces of laminated panels in construction are characterized. In this paper, a model has been developed for the theoretical study of shape change in lumber, which is proposed to be determined through the warping force, which causes the deformation of lumber. The engineering formulas for calculating the warping force that leads to lumber shape change were obtained. This force mainly depends on size, changes in moisture content and the location of the lumber in the cross-section of the log.