• Design of viscous dampers for the mitigation of actions induced by earthquake upon structures
The main research contributions in this field consist in the development of a 5-step design procedure to guide professional engineers through the whole design process of a structure equipped with viscous dampers, i.e., from the sizing of viscous devices to the design of structural member in order to achieve target seismic performance objectives. (details in [I1], [I16], [I25]]). Other results are related to (i) the calibration of behavior factors for structures equipped with viscous dampers (details in [I26]), (ii) the derivation of damping reduction factors based on a stochastic approach (details in [I12]), (iii) simplified estimations of inter-storey peak velocity profiles to be used in the preliminary design phase to estimate peak damper forces (details in [I14], [I17]), (iv) seismic behavior of frame structures equipped with strongback (details in [I2]).
• Seismic response of structures made with sandwich lightly-reinforced concrete walls
This research line comprises analytical, numerical and experimental studies to assess the cyclic non-linear behavior of structures made by RC sandwich panels. Experimental tests included cyclic pseudo-static tests upon panels in real scale, pseudo-dynamic tests upon a two story mock up, shake table test upon a 3 story real scale building (details in [I28], [I30]). The analytical predictions were developed modifying the modified compression field theory according to the specific constitutive behavior of shotcrete and reinforcement typically used for sandwich RC panels [I29]. The numerical predictions were carried out using an isotropic concrete damage model implemented in the open source software Opensees [I11]. The results evidenced good correlations between experimental behavior and analytical/numerical predictions. The experimental results proved that low-rise buildings made by RC sandwich walls re characterized by high seismic performances that together with the good insulation properties and reduced costs thus appearing of great appeal for construction in developing countries ([I5]).
The experimental activities were partially carried out within the European research project SESYCOWA (project SERIES funded by European Community).
• Development of the novel hysteretic device “Crescent Shaped Brace”
The Crescent Shaped Brace (CSB) is a steel hysteretic device that can be introduced into a frame to act as a hysteretic dissipative brace. The coupling of its material and geometrical non-linear behavior induced by its peculiar geometrical shape (e.g., a boomerang-like shape) determines a complex non-linear behavior that can be fine-tuned to satisfy specific seismic design requirements within a Performance-Based design approach (details in [I19], [I23]). The cyclic non-linear behavior of the device was verified through experimental tests carried out first on reduced-scale prototypes [I6], and then on a two-storey steel frame equipped with CSBs.
The experimental activities were partially developed within the research project RELUIS 3 and TiRiSiCo (PORFESR 2014-20 Emilia Romagna)
• Development of an innovative ductile unreinforced masonry system
This research activity, conducted thorough a large experimental campaign, has been carried out to develop an unreinforced masonry system characterized by superior seismic performances. The research project focused on a twofold objectives: (i) development of a mortar characterized by high ductility and high tensile strength, (ii) development of a new masonry unit for thin layers having superior thermal properties and good mechanical performances. The performances on the innovative masonry system were verified through both triplet tests and diagonal compression tests on meter-size masonry specimens.
The experimental activities were developed within the research project ITALICI (call Industria 2015) and ZERO (PORFESR 2014-20 Emilia Romagna).
• Structural analysis and monitoring of Historic Monumental Buildings
Our research combined advanced simulations tools (Discrete Element Method) with structural health monitoring techniques applied to predict the structural response of landmark monumental buildings such as the Asinelli and Garisenda Towers of Bologna and Modena Cathedral (details in [I13], [I18], [C1], [C2]).
The monitoring activities are currently carried out in collaboration with the Italian Institute of Geophysics and Volcanology INGV.
• Seismic induced torsional phenomena in planar eccentric structural systems
Development of predictive formulas for the estimation of the maximum seismic displacement demand of planar asymmetric buildings grounded on the key fundamental parameters controlling the behavior of those systems (i.e., the so-called alpha method, [I8] and [I27]).
More recently Dr. Palermo has approached the topics of seismic risk assessment and metal Additive Manufacturing:
• Assessment and mitigation of seismic risk at urban scale
An integrated bottom-up approach for the energy and seismic risk analysis of the built environment has been developed. A novel integrated (seismic/energetic) building taxonomy is proposed in order to describe the performance of buildings in an urban district utilizing a comprehensive approach allowing for a detailed seismic vulnerability diagnosis. The taxonomy is organized through a series of multidimensional tables, each of them collecting a number of information pertaining to several attributes. The procedure has been implemented in a web-based platform which allows simulating refurbishment interventions such as individual interventions for energy or seismic improvements or integrated packages. The platform also allows generation of thematic maps dealing with energy performances and seismic risk-related exposures of building at urban scale.
The research activates are carried out within the RIGERS research project (call Smart Cities2013).
- Mechanical and geometrical characterization / optimization of additive manufactured metal structures
The research aims at developing a groundbreaking additive manufacturing technology for 3D printing of metal grid-shell structures utilizing bio-inspired robots capable of moving and printing on the structures without the need for external support. The research has an inherent interdisciplinary nature and is carried out by a team with knowledge from diverse fields as Robotics and Control, Architecture, Structural design and metallurgy (coordinated by Dr. Michele Palermo). The team collaborates with the Dutch company MX3D, leader in the field of Wire and Arc Additive Manufacturing (WAAM). First research results comprise a detailed characterization of the metallurgic and mechanical properties of steel made by WAAM process. A prototype of the mobile robot printer is under development.
The research activities are partially carried out within the AUTOR3﴾d﴿ICOLARI project coordinated by Dr. Michele Palermo (Almaidea research programme funded by UNIBO).