1ST-ORDER RELIABILITY-ANALYSIS OF WOOD STRUCTURAL SYSTEMS

Computer simulation and an approximate method were used to study the l ifetime behavior of wood floor and roof systems. A simplified beam-spr ing model was used to model the systems. In this study, two-way action of the sheathing; partially composite action between the sheating, co nnectors, and lumber members; the random mechanical properties of the lumber members; the random postyield properties of the partially compo site members; and the cumulative damage of wood were included. The app roximate method was the firt-order reliability method incorporated wit h the distributions of order statistics. System reliability analysis, including system effects and load duration effects, is presented in th is paper. System factors for load and resistance factor design (LRFD) as they are related to component properties, mostly the postyield prop erties of partially composite members and variability of lumber modulu s of rupture (MOR), are determined. The results herein apply only to u niformly loaded systems simply supported at two edges.