Selection and scaling validation of ground motions according to TBEC-2018 for the seismic assessment of masonry structures

This paper addresses the selection and scaling of earthquake time histories for analysing masonry structures' Out-Of-Plane (OOP) response according to the 2018 Turkish Building Earthquake Code (TBEC-2018) guidelines. Ground motion simulations are proposed for regions with limited seismic networks or lacking information regarding recorded accelerograms for large-magnitude events. Selection and scaling procedures are automatised according to the TBEC-2018 recommendations. The pre-selection is conducted according to specific seismological characteristics, and the optimal scaling factors of individual records are computed using a metaheuristic optimisation based on the Differential Evolution Method (DEM). Two sets of records (11 real and 11 simulated) are generated and used as input to conduct non-linear dynamic analyses. A U-shaped masonry prototype is adopted as a structural benchmark. The structural response is monitored with an emphasis on the OOP response.ERC -European Research Council(LA/P/0112/2020

A concurrent micro/macro FE-model optimized with a limit analysis tool for the assessment of dry-joint masonry structures

A two-step strategy for the mechanical analysis of UnReinforced Masonry (URM) structures, either subjected to in- and out-of-plane loading, is presented. At a first step, a semi-automatic digital tool allows the parametric modeling of the structure that, together with an Upper bound limit analysis tool and a heuristic optimization solver, enables tracking the most prone failure mechanism. At a second step, a coupled concurrent FE model with micro- and macro-scales is assumed. A micro-modeling description of the masonry is allocated to regions within the failure mechanism found in the former step. In converse, the other domain regions are modeled via a macro-approach, whose constitutive response is elastic and orthotropic and formulated through closed-form homogenized-based solutions. The application of the framework is based on non-linear static (pushover) analysis and conducted on three benchmarks: (i) an in-plane loaded URM shear wall; (ii) a U-shaped URM structure; and (iii) a URM church. Results are given in terms of load capacity curves, total displacement fields, and computational running time; and compared against those found with a FE microscopic model and with a limit analysis tool. Lastly, conclusions on the potential of the framework and future research streams are addressed

Numerical Simulation of Fracture in Layered and Sandwich Structures: A Systematic Literature Review

A systematic literature review on numerical strategies suitable to simulate defects and discontinuities in layered and sandwich structures is presented here. Particular care is given to studies whose scope concerns the so-called Moving Mesh (MM) or Isogeometric Analysis (IGA) methods. A general overview of the peculiarities of each approach is also provided. A total of fifteen and twenty-six journal/conference articles were summarised and categorised for MM and IGA methods, respectively. Based on the available literature, it can be stated that MM approaches generally allow a lower computational burden due to the reduced number of re-meshing steps required when compared to standard finite element approaches. Conversely, IGA approaches bring strong advantages in the geometric description of curved shell structures and, due to a non-uniform rational b-spline interpolation function, ensure higher numerical accuracy in stress analysis problems.- (undefined