The aim of this work is to propose a new automatic procedure for the seismic assessment of partial failure mechanisms in historical masonry aggregates. Starting from the geometrical survey, a three-dimensional model of the whole aggregate is derived. The model is discretized through few NURBS surfaces (Non-Uniform Rational Bezier Spline) and imported into the MATLAB environment. A procedure of kinematic limit analysis is applied to a preselected part of the construction. The walls selected are subdivided into few elements, each one is a portion of the initial NURBS surface and is assumed as a rigid body. Rigid-plastic interfaces are defined on the boundary of each element. As a result, the kinematic limit analysis provides a local mechanism involving the selected walls and an associated kinematic multiplier. An optimization procedure, here conducted by using a Genetic Algorithm, is applied with the aim of finding the collapse multiplier. The procedure can take into account the most spread reinforcement techniques adopted in historical constructions, such as tie-rods and FRP strips, which maintain a local response to horizontal loads. An application to a historical masonry aggregate, located in the center of Arsita (Teramo, Italy), is finally presented.

Automatic assessment of partial failure mechanisms in retrofitted historical masonry aggregates through adaptive nurbs limit analysis

Grillanda N.;Valente M.;Milani G.
2020

Abstract

The aim of this work is to propose a new automatic procedure for the seismic assessment of partial failure mechanisms in historical masonry aggregates. Starting from the geometrical survey, a three-dimensional model of the whole aggregate is derived. The model is discretized through few NURBS surfaces (Non-Uniform Rational Bezier Spline) and imported into the MATLAB environment. A procedure of kinematic limit analysis is applied to a preselected part of the construction. The walls selected are subdivided into few elements, each one is a portion of the initial NURBS surface and is assumed as a rigid body. Rigid-plastic interfaces are defined on the boundary of each element. As a result, the kinematic limit analysis provides a local mechanism involving the selected walls and an associated kinematic multiplier. An optimization procedure, here conducted by using a Genetic Algorithm, is applied with the aim of finding the collapse multiplier. The procedure can take into account the most spread reinforcement techniques adopted in historical constructions, such as tie-rods and FRP strips, which maintain a local response to horizontal loads. An application to a historical masonry aggregate, located in the center of Arsita (Teramo, Italy), is finally presented.
Proceedings of the International Conference on Structural Dynamic , EURODYN
Adaptive limit analysis
Historical masonry aggregates
Local mechanisms
NURBS
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1157714
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