RELIABILITY ANALYSIS OF TIMBER STRUCTURE DESIGN OF POPLAR LUMBER WITH NONDESTRUCTIVE TESTING METHODS

The safety of timber structure design based on the predicted Modulus of Rupture (MOR) of poplar lumber with nondestructive methods is presented in this paper. Dynamic Modulus of Elasticity (MOE) of poplar lumber was measured with three different nondestructive methods, and static MOE and MOR were obtained by a static bending test. The regression relationship between various MOE and MOR was evaluated to predict MOR with various MOE. Then timber construction design was conducted on poplar lumber based on measured and predicted MOR. Furthermore, reliability of timber structure design was analyzed with advanced first-order second-moment method. Results indicated that mean values of predicted MOR were slightly greater than those of measured MOR, but Coefficient of Variation (COV) of them were less than those of measured MOR. The reliability index of timber structure design based on predicted MOR, varying from 2.404 to 2.574, was less than that on measured MOR as 2.831.