SEMIRIGID ANALYSIS OF METAL PLATE-CONNECTED WOOD TRUSSES USING FICTITIOUS MEMBERS

The focus of this article is analysis of a truss by including the semi -rigidity of the truss joints using fictitious members. Results from s imulating the semi-rigid connection with fictitious members are compar ed with results from analyses made with the following truss joint conn ection assumptions: 1) pin connection; 2) rigid connection; 3) the Tru ss Plate Institute (TPI) specification for truss analysis; and 4) semi -rigid connection simulated by modifying the fixed-end forces and elem ent stiffness matrices. Sensitivity analyses were conducted to examine the effect of: 1) truss slope; 2) axial and rotational stiffnesses of the joints; and 3) random assignment of modulus of elasticity (MOE) f or truss members on the maximum truss deflection, and maximum axial fo rce and bending moment of members as determined by the fictitious memb er method. The maximum vertical reflection of the truss and maximum be nding moment of the truss members using fictitious members fall in bet ween the results for the pinned and rigid joint connection assumptions and are less than that using the matrix method. The TPI analysis spec ification adequately incorporates the semi-rigidity of truss joints. T he deflection, ben&ng moment, and axial force predicted by the fictiti ous member procedure were sensitive to roof slope, but relatively less sensitive to changes in joint axial and rotational stiffnesses and ra ndom assignment of MOE values for truss members.