INELASTIC ANALYSIS OF PRISMATIC AND NONPRISMATIC ALUMINUM MEMBERS

Today, many structures are subjected to stresses beyond the elastic li mit of the material, creating a loading condition of great significanc e to the design engineer. This is particularly important for aircraft and aerospace structures and for any structure subject to earthquake a nd blast loads. Since both prismatic and nonprismatic members may be u sed in these structures, the analysis can be very complicated, especia lly when the moment of inertia I(x) and the modulus of elasticity E(x) vary along the length of the member. The method of equivalent systems development by Fertis [Dynamics and Vibration of Structures. John Wil ey (1973); revised Edn., Krieger (1984)], Fertis and Keene [J. Struct. Engng 116(2) (1990)] and Fertis and Taneja V. Struct. Engng. 117(2) ( 1991)] provides an accurate and simplified method of analysis for the solution of such problems in ferrous alloys. This paper deals with the utilization of equivalent systems of constant stiffness E1I1, where b oth E(x) and I(x) of the original member are permitted to vary in any arbitrary manner, in order to determine the rotations and deflections of prismatic and nonprismatic aluminum alloy members. In the analysis, the material of the member is permitted to be stressed well beyond it s elastic limit, and all the way to failure.