Modelling the seismic response of a 2-storey URM benchmark case study: comparison among different equivalent frame models

Carlo Filippo Manzini,Corrado Marano,Daria Ottonelli,Stefania Degli Abbati,Emilia Angela Cordasco

doi:10.1007/s10518-021-01173-2

Abstract

The paper presents the comparison of the results of non-linear static analyses performed with different software based on the equivalent frame (EF) modelling approach on a simple two-story unreinforced masonry building with rigid diaphragms. This study is part of a wider research activity carried out in the framework of the Italian Network of Seismic Laboratories (ReLUIS) projects, funded by the Italian Department of Civil Protection. Different configurations have been considered varying the layout of the openings on the bearing walls and the structural details. The EF models have been defined adopting as much as possible common assumptions, in order to reduce the epistemic modelling uncertainties and to facilitate the interpretation of the differences in the results obtained by the software. The comparison involved different aspects: the global scale response, in terms of capacity curves, the predicted damage pattern as well as checks at the local scale, in terms of distribution of the generalized forces. Moreover, in order to assess the reliability of the obtained results, the numerical predictions have been compared to an analytical upper bound reference solution. Finally, the sensitivity of the numerical response to the criterion adopted for the EF idealization of masonry walls has been investigated.

Highlights

The use of computer programs is nowadays a common practical resource for researchers and professional engineers
The results of non-linear static analyses performed with seven commercial software based on the Equivalent Frame (EF) approach are presented, while Cannizzaro et al (2021) treats the same topic with reference to software packages employing different Finite Element (FE) modelling strategies using either two- or three-dimensional elements
It is expected that the presented topics will constitute a useful contribution for both professional engineers and the scientific community

Summary

Introduction

The use of computer programs is nowadays a common practical resource for researchers and professional engineers. Software packages are useful, if not quite indispensable, both for the design of new structures and for the assessment of existing ones. The problem of their reliability and correct use is more and more recognized by associations and codes, representing a critical issue for the correctness of the obtained numerical results. In the specific field of masonry buildings, in the last decades the Equivalent Frame (EF) modelling approach has achieved great success, both at research level and for practice engineering aims, due to its simplicity of implementation and computational efficiency with respect to the Finite Element (FE) approach, even for non-linear analyses. The wide availability of EF model-based computer programs results in a huge variety of options, and in a potential scattering of achievable results (e.g. Mendes et al 2017; Esposito et al 2019; Parisse et al 2021), especially when analysts adopt the default settings, without proper knowledge of the software features and experience in the modelling approach

Objectives

Findings

Discussion

Conclusion