Smeared crack material modelling for the nonlinear analysis of CFRP-strengthened historical brick vaults with adobe piers

Abstract

The collapse of non-engineered, historical, masonry buildings in seismically-active regions of Iran has been widely reported. FRP-strengthening techniques can be effectively used for lateral, load-carrying improvements. Numerical modelling can also be used as a cost-effective tool for the design of strengthening schemes. A two-step, macro-modelling approach is proposed and the performance of a CFRP-retrofitted, historical building is evaluated in this paper. The brick and adobe, prism samples of the building have been modelled by a commercial code, which uses smeared-crack materials and eight-noded isoparametric, solid elements. Nonlinear, stress-strain curves have been obtained and calibrated with experimental data for undamaged prisms as previously reported by this author. Complete stress-strain curves of damaged/undamaged brick and of undamaged adobe prisms have been used in the second step to monitor potential failures of the building. The brick vault was initially strengthened with FRP at extrados and this was followed by a strengthening of the extrados and piers. Solid elements with anisotropic, material properties were used for the FRPs. A comparison of these results with the current, simple, homogenized models demonstrated the efficiency of the proposed macro-modelling. When the vault was strengthened entirely at the extrados only, both its strength and ductility were improved whereas just using one strip at the extrados and the piers led to a big improvement in the load-carrying capacity despite a slight increase in the ductility.