Andrea Benedetti

Teh research activity of Dr Benedetti is focused on the themes encompassed by the field of structural health of ancient and monumental buildings in seismic zones. The main topics considered are:

- durability of structures exposed to environmental and accidental actions,

- structural rehabilitation and strengthening by means of fiber reinforced materials and innovative techniques,

- fire damage in structural materials and restoration techniques,

- seismic vulnerability of masonry constructions and bridges,

- seismic analysis of prefabricated buildings with dry joints.

The problem of the evaluation of the residual safety margin of R/C structures damaged by severe fire accidents has been discussed with reference to analytical constitutive response formulation and non destructive experimental assessment, arriving at practical solution of engineering relevance.

The procedure for the damage assessment released by Dr Benedetti is continuously updated including new examples and mixed site – laboratory cross referencing test methods and is actually under examination by many other researchers.

Dr. Benedetti has been an active researcher in the field of non linear dynamical problem solution; in this respect, a versatile general algorithm for the solution of non linear problems in the frequency domain has been proposed and thoroughly tested.

Actually, in collaboration with Dr. Cosentino, a theoretical and experimental program for the characterization of distributed damping devices in cable dynamics is under development.

The peculiar field of ancient masonry structures analysis and restoration is of paramount importance for Europe and particularly for Italy. Basic solutions have been proposed for this topic regarding the compression strength of ancient brick and rubble masonry, and the problem of masonry walls with multiple brick types randomly mixed.

Some new studies on the seismic reliability of quasi fragile systems of masonry walls are in progress and a first analysis has been submitted to ICOSSAR 5 for presentation.

With reference to an advanced production technology for light alloy modular component production, a wide theoretical and experimental study was undertaken in order to enhance the high cycle fatigue resistance of the system. The research is under development and the first important findings have been presented in international Congresses.

Starting with one of the earlier strengthening operations completed in Italy in the last decade, Dr. Benedetti has worked out design methods and ideas for the efficient solution of the reinforcement net calculation and specification in strengthening commitments.

A general method for the design of shear – flexural reinforcement of beams ahs been recently published including a thorough discussion of more than 130 experimental tests found in the literature.

Several problems related to the prediction of the capacity of reinforced concrete sections and elements acted on by repeated loading in the low cycle fatigue range have been analysed and discussed, including singular phenomena like bar buckling after spalling and crack opening of precast elements.

The early sectional analysis was advanced producing a special beam – column finite element for non linear analysis of R/C structures. The main contribution has involved the development and testing of a novel fibre finite element based on a hybrid variational principle, able to solve material and geometric non linear problem with very coarse meshes. Some application included soil – structure interaction problem solutions.

Finally, a novel beam finite element based on the spline reconstruction of the axis line and a self equilibrated formulation of the stress field has been proposed. Applications to the complementary energy based modal analysis and to high precision thick curved structure solution showed the efficiency and robustness of the proposed technique. The proposed element, was also extended to the field of non linear analysis of curved structures with distributed plasticity of the material constitutive law. The element formulation based on a collocation method showed robustness and very high precision.