Limit state approach for structurally informed design of shells composed of interlocking blocks

This work demonstrates an extension of limit analysis with concave model to design 3D assemblages of dry jointed interlocking rigid blocks with orthotropic sliding resistance. A digital framework is developed to design and analyse the structural feasibility of assemblages of interlocking blocks. The sliding resistance is defined as a function of the geometric properties of the interlocking interface. Adjusting the geometric parameters, designers can modify the infeasible models to be stable. The limit states are governed by two types of failure planes including dry joints and fracture strips between the locks and the main body of the block. These planes are merged and simplified to an orthotropic interface between two blocks. Then, the interface is abstracted to a number of point contact points distributed on lock centrelines, at which the stress resultants are computed by solving the equilibrium problem under proper sliding constraints. Applying this method, the limit conditions for several single layer shells with hexahedral units assembled with stack bond are illustrated.