Steel based retrofitting interventions for existing masonry walls: a comparative numerical investigation

Masonry buildings constitute a significant portion of the architectural heritage all over the world, also in regions affected by a high seismic hazard. Since this constructional material is characterized by lack of tensile strength, as well as small deformation capacity, masonry structures could result hugely damaged if shaken by seismic forces. In order to avoid collapses and reduce structural damage, innovative retrofitting interventions are necessary to improve the seismic behavior of masonry structures. In this context, steel-based techniques could be considered among the most suitable solutions. In fact, by using such a high-performant material, additional strength and ductility may be conferred to existing masonry structures. Based on these premises, the present paper focuses on a numerical investigation of two different retrofitting techniques: the CAM© system and the application of steel grids on both faces of a masonry wall. In particular, on the base of an experimental test carried out within the research project In.CAM.M.I.N.O. on an unreinforced masonry wall tested in condition of constant vertical force and horizontal loads, a reference FE Model has been calibrated in Abaqus by using a macro-modelling approach with a damage-plasticity material model for the masonry. Then, based on the reference model, the efficiency of the two systems has been investigated and compared by means of numerical analyses, in order to evaluate the strength and ductility increases obtainable by the application of the two retrofitting techniques

Influence of Column Axial Load and Heat Affected Zone on the Strength of Aluminium Column Web in Tension

The component method for aluminium joints has been recently introduced in some codes and guidelines. Nevertheless, it is still in need of some development and improvement, as in some cases it was obtained by adapting the existing formulations that are valid for steel. The current paper presents the main outcomes of a parametric analysis carried out by means of finite element (FE) numerical models for determining the influence of both column axial load and heat affected zone—in the case of welded details—on the structural response of the column web in a tension component. The proposed study integrates previous research carried out by the authors, where the influence of the assumed alloy was investigated and interpreted by corrective parameters expressed as a function of both the material strain hardening and ductility

Design of low strength-high hardening metal multi-stiffened shear plates

In this paper design curves for low strength-high hardening metal multi-stiffened shear plates are provided, based on both experimental tests and parametric numerical analyses. To this aim, an almost pure aluminum is considered as base material, it being characterized by a yielding stress point of about 20. MPa and a hardening ratio higher than 4.An "initial stability" curve, which is useful to determine service limit conditions for metal plates in shear, is outlined with the aim of establishing the early buckling phenomena. Then, design curves providing the reduction factor of the ultimate strength of the plate in shear duly accounting for buckling phenomena are proposed as a design tool for system dimensioning.Finally, the issue related to the design of stiffeners, which are applied to delay shear buckling and to improve the plate hysteretic performance, is investigated. The current study represents an extension of the outcomes provided in a previous paper [4] (Brando and De Matteis, 2011), where the above design curves have been provided for hardening aluminum shear plates without stiffeners

Hydrocarbon explosion loading

COST C12 - WG2 Datasheet: Final Scientific report of the COST Action C12 - Improvement of Buildings Structural Quality by New Technologies - Outcome of the Cooperative Activitie