A new approach to the limit analysis of masonry structures as assemblies of rigid-plastic blocks with frictional sliding contacts

Due to the lack of an associated flow in frictional sliding, the collapse load of an assembly of rigid-plastic blocks with frictional contacts depends on the loading history and cannot be studied in the context of standard limit analysis. In this work a theorem is developed to characterize the collapse states of these mechanical systems. In particular, the concept of kinematically admissible load multiplier is extended to these systems and it is established that if a load multiplier is both kinematically and statically admissible then it is a collapse multiplier. Based on this result, various plane masonry structures are examined, considering both Coulomb frictional sliding at blocks interfaces and plastic deformations. To take into account the lack of uniqueness of the load multiplier, its minimum and maximum values are determined. The numerical applications demonstrate the potential of this approach for assessing the collapse load of masonry-like structures.