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To evaluate the seismic stability of Mustafa Pasha Mosque in Skopje strengthened by an advanced mixed technology, shaking table tests were carried out on a model in scale 1:6. The investigation was performed within the activities of the Sixth Framework Program PROHITECH - oEarthquake Protection of Historical Buildings by Reversible Mixed Technologieso. To define the effectiveness of the proposed strengthening the testing procedure consisted of two main phases: testing of the original model and testing of the strengthened model. The observed seismic behavior and damage during each phase of the testing program were analyzed on the basis of the obtained experimental results.

A finite element model of laser welded connections was developed in this paper for the analysis of structural behaviour of built-up cold-formed steel members. The implemented FE model uses unidirectional elements with nonlinear generalized force-deflection capability and was calibrated on the basis of lap-shear experimental tests on laser welded connections carried out at the University of Naples. In order to validate the use of the implemented FE model, an application was presented to simulation of a built-up cold-formed beam assembled by multiple laser welds. In particular, the compression flange of the selected beam was investigated, by comparing experimental and numerical results.

The experimental and analytical results presented in this paper are a part of the activities performed within the Sixth Framework Program PROHITECH - "Earthquake protection of historical buildings by reversible mixed technologies". For the selected prototype structure - historical monument Mustafa Pasha Mosque in Skopje, 1/6-scale model was constructed and tested on seismic shaking table in several phases. The main aim of experimental model testing was to investigate the seismic stability of the monument after applying a reversible technology for strengthening. Beside the experimental shaking table testing of the model, three-dimensional finite element analyses were carried out using the general purpose software package ANSYS. The main aim of the numerical simulations was to predict the response of the large scale model during the shaking table tests. The results of finite element analysis have been compared with the experimental outcome, discussing the differences between the predicted seismic capacity and the experimental one for each phase of the test program. The evolution of partial and global collapse mechanisms observed during the tests has been also analyzed on the basis of numerical results.

This paper is concerned with the analysis of the seismic performance of the historical monument Mustafa Pasha Mosque in Skopje strengthened with FRP. The study was carried out by means of finite element and limit analysis. The main aim of numerical investigations was to control the response of the structure during the shaking table tests carried out on both the original and reinforced large scale model of the Mosque that was built at the IZIIS Laboratory in Skopje. In order to properly evaluate the structural interactions among the different parts of the specimen, a three dimensional finite element model of the Mosque was implemented. All the main elements of the building were simulated accurately, including the openings and the pendentives connecting the walls with the dome. In addition, a simplified modelling approach based on the limit equilibrium analysis of collapse mechanisms was developed in order to evaluate the ultimate load of both original and reinforced model. The results obtained from finite element and limit analysis were compared with the experimental outcome, showing the differences between the predicted and measured seismic capacity for each phase of the test programme. The evolution of partial and global collapse mechanisms observed during the tests has been also analyzed on the basis of numerical results.

In this paper the seismic performance of the iron roofing structure of the Umberto I Gallery in Naples is investigated by means of a three dimensional finite element model. The geometric and mechanical properties of the structure have been obtained through a wide investigation on available historical documentation. The considered design actions, namely self-weight, wind, snow and seismic loads, have been evaluated and combined on the basis of the Eurocode provisions. The numerical results allow the actual safety factor respect to both the ultimate and serviceability limit states to be evaluated. Some considerations on the structural vulnerability to corrosion damage are also developed. In particular, the influence of the atmospheric corrosion has been assessed on the basis of a specific modelling procedure which takes into account the main factors affecting this phenomena.

A wide experimental investigation on laser welded connections based on both lap-shear and tension tests was performed at the University of Naples. The aim of the study was to assess the possibility of using laser welding in innovative built-up cold-formed steel beams. The experimental programme was designed in order to evaluate the effects of different parameters on the strength and ultimate displacement of the selected connections. In particular, the influence of sheet thickness, gap, loading direction, weld shapes and zinc coating were analyzed. The results of the experimental tests were compared with the predicted resistance values according to Eurocode 3, with the aim of validating for laser welding the mechanical models provided for spot welds.

The results of a research project aimed at designing and development a built-up cold-formed steel beam assembled by laser welding are described in this paper. The research activity was concerned with the evaluation of the applicability of laser welded connections to cold-formed members and with the assessment of the load bearing capacity of the assembled beams. With this aim, both lap-shear and U-tension tests were carried out on laser welds in order to assess the influence on connection strength of different parameters such as the gap between the steel sheets and the zinc coating. Finally, the load bearing capacity of laser welded built-up cold-formed members was investigated by four-point bending tests. Four full-scale prototypes were manufactured with different spacings of connections along the flanges in order to evaluate the effects of weld configuration on the load bearing capacity.

To investigate the effects of contact interactions on local buckling of a built-up cold-formed steel member assembled by laser welding a finite element model was developed. The numerical model was validated against the experimental results of a four point bending test on a full scale specimen. A good agreement with test data was observed both in terms of ultimate bending strength and deformed shape at collapse. The calibrated finite element model was used to estimate the effects on buckling resistance of contact forces between the parts of the beam by varying the connection spacing on the flanges. As a main result, it was shown that contact interactions influence remarkably the ultimate strength of the beam and that their effects decrease with decreasing spacing of connections.