A theory of cross-sectional shrinkage distortion and its experimental verification
1992
Booker, R. | Ward, N. | Williams, Q.
A theory has been developed for calculating the cup and edge distortion that will occur when green boards are dried, or the moisture content of dry boards changes in service. The parameters on which the calculations are based are the annual ring orientation coordinates R and theta of the boards, and the transverse shrinkage factors. For boards of square-cross-section the theory agrees very closely with the shrinkage predicted by the older theory of Greenhill, MacLean and Keylwerth. For Beilschmiedia tawa specimens 50 X 50 mm in cross-section the experimental and calculated width and thickness shrinkage were in excellent agreement. For radiata pine boards 200 X 50 mm in cross-section the experimental cup, edge distortion and shrinkage in width and thickness agreed very closely with the values predicted by the theory.
显示更多 [+] 显示较少 [-]