Upper Bound limit analysis model for FRP-reinforced masonry curved structures. Part I : unreinforced masonry failure surfaces

A two-steps approach for the FE limit analysis of FRP reinforced curved masonry structures is presented in this paper. In step I, discussed extensively in the present Part I, a simplified kinematic procedure is proposed at a cell level to obtain macroscopic masonry behavior in the case of unreinforced masonry curved structures. In step II, discussed in the companying paper (Part II) strips are applied at a structural level on the already homogeneous material. Unreinforced masonry strength domain is obtained by means of a compatible approach in which each brick is supposed to interact with its six neighbors by means of rigid-plastic interfaces with frictional behavior representing mortar joints. A sub-class of possible elementary deformations is a-priori chosen to describe joints cracking under in- and out-of-plane loads. Suitable internal macroscopic actions are applied on the boundary of the representative element of volume, in analogy to the flat case. The limit analysis problem at a...