Search results for " Structural"
showing 10 items of 1751 documents
Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study
2016
Abstract Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, relia…
Estimation of air pollutant emissions in flower roundabouts and in conventional roundabouts
2013
Abstract The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the flower roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the capacity, delay, levels of service and the pollutant emissions into flower roundabouts. A comparative analysis between conven…
New Stage-Discharge Equation for the SMBF Flume
2016
AbstractFlumes for indirect discharge measurements are widespread and are characterized by a particular shape of the cross section area with various degrees of convergence and subsequent divergence. The flume named Samani, Magallanez, Baiamonte, Ferro (SMBF) is a simple and inexpensive instrument and its channel contraction is obtained by applying two semicylinders to the walls of a rectangular cross section. At first, in this paper a new stage-discharge equation for the SMBF flume is theoretically deduced. Then, this equation is experimentally calibrated using the laboratory measurements from the literature for different values of the contraction ratio. Finally the field measurements carri…
The Transverse Crack Tension test revisited
2016
Several problems arise when measuring the mode II interlaminar fracture toughness using a Transverse Crack Tension specimen; in particular, the fracture toughness depends on the geometry of the specimen and cannot be considered a material parameter. A preliminary experimental campaign was conducted on TCTs of different sizes but no fracture toughness was measured because the TCTs failed in an unacceptable way, invalidating the tests. A comprehensive numerical and experimental investigation is conducted to identify the main causes of this behaviour and a modification of the geometry of the specimen is proposed. It is believed that the obtained results represent a significant contribution in …
Frictional effects in structural behavior of no-end-connected steel-jacketed RC columns: Experimental results and new approaches to model numerical a…
2017
Steel jacketing of reinforced concrete (RC) columns is a common retrofitting technique used to restore bearing and deformation capacity of buildings presenting structural deficiencies. For practical reasons, steel angles are in several cases arranged leaving a gap with the end beams or slabs. Despite this disconnection, the angles are still able to support a non-negligible portion of load because of the frictional forces developed along the column-angle contact interface. In these cases, the definition of computational numerical and analytical models for the assessment of reinforced cross sections becomes more complex and must be handled with care. The actual load-carrying capacity of the a…
Multi-objective optimized management of electrical energy storage systems in an islanded network with renewable energy sources under different design…
2014
The subject addressed in this paper is the definition of some strategies for the design and the optimaized management of EES (Electrical Energy Storage) systems, for an existing islanded distribution network supplying the Island of Pantelleria (Italy) in the Mediterranean Sea. In the paper the authors have drawn interesting conclusions through the application of an efficient MO (multi-objective) optimization algorithm, the NSGA-II, minimizing the energy losses in the grid, the total electricity generation cost and the greenhouse gas emissions. The results obtained for different installation scenarios of the EES are presented and discussed, putting into evidence the technical, environmental …
Unified formulation for a family of advanced finite elements for smart multilayered plates
2016
AbstractFamilies of layer-wise and equivalent single-layer advanced finite elements for the analysis of smart multilayered plates are formulated in a unified framework. The proposed modeling strategy reduces the multifield problem to an effective mechanical plate by the condensation of the electromechanical state into the plate kinematics, which is assumed as a variable order expansion along the plate thickness. Carrera Unified Formulation is invoked to derive the elemental stiffness and mass matrices and the mechanical and magneto-electric equivalent forces. The obtained smart plate finite element equations involves kinematical variables only and this extends the tools developed for multil…
A novel hybrid polygeneration system supplying energy and desalinated water by renewable sources in Pantelleria Island
2017
Abstract In this paper a thermoeconomic analysis of a novel hybrid Renewable Polygeneration System connected to a district heating and cooling network is presented. The plant is powered simultaneously by solar and geothermal sources, producing electricity, desalinated water, heat and cooling energy. System layout includes Parabolic Through Collector (PTC) field, geothermal wells, Organic Rankine Cycle (ORC) unit and a Multi-Effect Desalination (MED) system. Cooling and thermal demands are calculated by suitable building dynamic simulation models, calibrated for Pantelleria Island. Electrical demand is obtained by measured data. A detailed control strategy has been implemented in order to pr…
Influence of secondary torsion on curved steel girder bridges with box and I-girder cross-sections
2015
Steel curved girder bridges are largely used today in motorways and railways. They are often composed of thin-walled crosssections, entirely made of steel or with an upper concrete slab. The deck may have I-girders or box cross-sections: in any case curved girders are subjected to twisting moment, associated with bending, even for dead loads. Moreover, in thin-walled sections the influence of non-uniform torsion becomes sizable with respect to Saint Venant torsion, modifying the state of tangential stresses in the section and introducing axial stresses due to warping being prevented. Open sections of I-girder bridges are especially subject to these phenomena and warping can be significant n…
INTERNAL PRESSURE AND COUNTERPUNCH ACTION DESIGN IN Y-SHAPED TUBE HYDROFORMING PROCESSES: A MULTI OBJECTIVE OPTIMISATION APPROACH
2009
In sheet metal forming most of the problems are multi-objective problems, generally characterised by conflicting objectives. A classical approach to investigate such kind of problems is focused on a combination of multiple objectives into a unique objective function to be optimised. Actually, in metal forming processes optimisation two main phases have to be developed in order to reach an optimal solution: the former is the modelling phase (definition of the design variables and objective function) and the latter concerns the computational aspect (numerical simulations or experiment to be developed). In this paper, an integration between numerical simulations, response surface methodology a…