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In this paper, a new semi-automatic procedure to transform three-dimensional point clouds of complex objects to three-dimensional finite element models is presented and validated. The procedure conceives of the point cloud as a stacking of point sections. The complexity of the clouds is arbitrary, since the procedure is designed for terrestrial laser scanner surveys applied to buildings with irregular geometry, such as historical buildings. The procedure aims at solving the problems connected to the generation of finite element models of these complex structures by constructing a fine discretized geometry with a reduced amount of time and ready to be used with structural analysis. If the starting clouds represent the inner and outer surfaces of the structure, the resulting finite element model will accurately capture the whole three-dimensional structure, producing a complex solid made by voxel elements. A comparison analysis with a CAD-based model is carried out on a historical building damaged by a seismic event. The results indicate that the proposed procedure is effective and obtains comparable models in a shorter time, with an increased level of automation.

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ReuseThis article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) licence. This licence only allows you to download this work and share it with others as long as you credit the authors, but you can't change the article in any way or use it commercially. More information and the full terms of the licence here: https://creativecommons.org/licenses/ TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. ABSTRACTIn this paper, a 3D detailed micro-model for the in-plane and out-of-plane numerical analysis of masonry structures is proposed. Representative Elements consisting of one brick and few mortar layers are explicitly modelled using 3D solid finite elements obeying to plastic-damage constitutive laws (one for brick and one for mortar) conceived in the framework of nonassociated plasticity. This permits to represent the brick and mortar mechanical behaviour when cracking and/or crushing occur. Representative Elements are assembled, accounting for any actual 3D through-thickness arrangement of masonry, by means of zero-thickness cohesive interfaces based on the contact penalty method. In the pre-failure of interfaces, all the significant deformability of the system is addressed to the 3D finite elements. A Mohr-Coulomb failure surface with tension cut-off is adopted. The post-failure interfacial response is characterized by a cohesive behaviour in tension and a cohesive-frictional behaviour in shear, which appears consistent with small-scale tests outcomes. Experimental-numerical comparisons are provided for the in-plane and out-of-plane behaviour of masonry panels. The accuracy and the potentialities of the modelling approach are shown. The direct characterization of all the model parameters from small-scale tests, as well as their clear mechanical meaning constitute further appealing qualities of the model proposed.

In this paper, a damaging block-based model is proposed for the numerical analysis of the cyclic behaviour of full-scale masonry structures. Solid 3D finite elements governed by a plastic-damage constitutive law in tension and compression are used to model the blocks, while a cohesive-frictional contact-based formulation is developed to simulate their cyclic interaction. The use of tests on small-scale specimens to calibrate the mechanical properties of the numerical model is presented and discussed. The tests belong to a comprehensive experimental campaign performed on calcium silicate brick masonry. The calibrated models are used to simulate in-plane and out-of-plane cyclic tests on masonry walls made of the same material, as well as a quasi-static cyclic pushover test on a full-scale terraced masonry house. The efficiency, the potentialities and the accuracy of the model here proposed are shown and discussed. The capability of explicitly representing structural details (e.g. running bonds) and any in-plane and through-thickness texture of masonry, which appears essential to study the response of masonry structures, is guaranteed by the block-based modelling approach. A good agreement between the numerical results and the experimental outcomes is observed. This allows to validate the model in the cyclic response as well as the strategy proposed for its mechanical characterization.

This paper presents a vibration-based model updating procedure for historical masonry structures which have suffered severe damage due to seismic events.This allows gathering in-depth insights on the current condition of damaged buildings, which can be beneficial for the knowledge of their actual structural behaviour and, consequently, for the design of repairing and strengthening interventions. The methodology, based on the experimentally identified modal parameters, is tested on the San Felice sul Panaro medieval fortress, which was heavily damaged by the 2012 Emilia earthquake. The finite element mesh of the structure in its post-quake condition is generated by means of a nonstandard semi-automatic mesh generation procedure based on a laser scanner points cloud. Ambient vibration testing is performed on the main tower of the fortress. Mechanical properties of the tower and the level of connections with the rest of the fortress in its current damaged state are investigated. To fully characterize the actual behaviour of the tower in operational condition, mesh elements corresponding to the damaged masonry are identified and different material properties are assigned to them. This allows to account for the effect of damage and cracks, which appeared essential in the calibration process. The updating procedure is carried out by means of an advanced surrogate-assisted evolutionary algorithm designed for reducing the computational effort.

In this paper, numerical insights on the seismic behavior of a non-isolated historical masonry tower are presented and discussed. The tower under study is the main tower of the fortress of San Felice sul Panaro, a town located near the city of Modena (Italy). Such a tower is surrounded by adjacent structural elements and, therefore, is not isolated. This historical monument has been hit by the devastating seismic sequence occurred in May 2012 in the Northern part of the Emilia region (the so-called â\u80\u9cEmilia earthquakeâ\u80\u9d), showing a huge and widespread damage. Here, in order to understand the behavior of the structure, its interaction with the adjacent buildings and the reasons of the occurred damage, advanced numerical analyses (both nonlinear static and dynamic) are performed on a 3D finite element model with different levels of constraint supplied by the adjacent structural elements and a detailed comparison between the simulated damage and the actual one is carried out. The results of the conducted numerical campaign show a good agreement with the actual crack pattern, particularly for the model of the tower that considers the adjacent structural elements

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