STRUCTURAL CONCRETE - CRACKED MEMBRANE MODEL

After a review of limit analysis and compression field approaches and a discussion of a recently developed tension chord model, this paper p resents a new model for cracked, orthogonally reinforced concrete pane ls subjected to in-plane stresses. The cracked membrane model combines the basic concepts of the modified compression held approach and the tension chord model. Crack spacings and tensile stresses between the c racks are determined from equilibrium conditions and bond shear stress -slip relationships, and the link to limit analysis is maintained sinc e equilibrium conditions are formulated in terms of stresses at the cr acks rather than average stresses between the cracks. Both a general n umerical method and an approximate analytical solution are derived and corresponding results are compared with previous theoretical and expe rimental work. In addition, a computational procedure is proposed that makes it possible to treat cracks as fixed and interlocked rather tha n as rotating and stress free. implementation of this procedure is rec ommended for future research.