In this paper, a numerical modelling-based damage diagnostics methodology is proposed for cultural heritage structures (CHSs) made of masonry. Firstly, an integration of 3D documentation data (i.e. point clouds and virtual tours) is developed for the rapid numerical model generation of CHSs. This allows to directly exploit non-comprehensive point clouds (e.g., associated to outer surfaces only) for the solid finite element model generation, where the lacking information is merged with off-site interactive and immersive frameworks. Secondly, a number of nonlinear static and dynamic analyses are conducted on the generated solid model to account for various load scenarios (e.g., earthquakes, soil settlements, etc.), considering a nonlinear continuum constitutive law. Thirdly, a crack pattern matching indicator is introduced to quantitatively identify the most likely load scenario which originated the damage pattern present in the CHS, by comparing numerical and actual crack patterns. The proposed methodology allows to rapidly generate and extract the numerical model that reflects the current (damaged) state of the CHS. This also allows to identify the parts of the CHS susceptible to further damage. The effectiveness of the proposed methodology is promisingly assessed on an actual historical masonry structure, the Morris Island lighthouse in South Carolina (USA)
