Search results for "0201 civil engineering"
showing 10 items of 242 documents
Modelling of a hydro-pneumatic system for heave compensation
2018
This paper presents a mathematical model of the dynamic behaviour of a passive heave compensation system. The main purpose is to develop a model that enables cost-efficient prototyping and testing of the control system in an active heave compensator. The physics are described by first principles, and result in 21 ordinary differential equations. Temperature calculations are included as an option during simulation in order to investigate its effect on the results. Similarly is a non-ideal gas law (Redlich-Kwong equation) implemented and compared to the ideal gas law. Verification against field data shows that the model is in good accordance with real-life drilling operations. It is further s…
Experimental calibration of flat jacks for in-situ testing of masonry
2018
Flat-jack testing method is one of the most commonly used techniques for the structural assessment of existing masonry structures. Single and double flat jacks are usually adopted to evaluate the acting normal stress, or the compressive behaviour of masonry material. Test procedures are codified by international standards (e.g., A.S.T.M D4729-87; C1196-04; C1197-04, R.I.L.E.M TC 177–MDT D.4; R.I.L.E.M. TC 177–MDT D.5), which provide the preliminary calibration of an experimental coefficient (km) and of the effective area (Aeff), which determination influences significantly the reliability of the test. This article presents the result of an experimental study on the calibration of flat jacks…
Empirical Equations for the Direct Definition of Stress–Strain Laws for Fiber-Section-Based Macromodeling of Infilled Frames
2018
Equivalent strut macromodels are largely used to model the influence of infill walls in frame structures due to their simplicity and effectiveness from a computational point of view. Despite these advantages, which are fundamental to carrying out seismic simulation of complex structures, equivalent struts are phenomenological models and therefore have to conventionally account for the influence of really large amounts of geometrical and mechanical variables with a relatively simple inelastic response. Mechanical approaches, generally used to evaluate the force-displacement curve of a strut, are based on hypothesizing the damage mechanism that will occur for an infill-frame system subject to…
Macroelement Model for the Progressive-Collapse Analysis of Infilled Frames
2021
A new multistrut macromodel for the analysis of the progressive-collapse response of infilled reinforced concrete (RC) frames is presented in this paper. The model consists of three struts: two outer infinitely rigid and resistant struts and one inner fiber-section strut. The inclination of the struts as well as the stress-strain response are modulated by two parameters that are obtained by means of analytical correlations provided in the paper. The latter link the geometric and mechanical properties of an infilled frame to the geometric configuration and mechanical response of the equivalent strut model. This confers the model the capability to adapt to consider different collapse configur…
Pyrolysed cork-geopolymer composites: A novel and sustainable EMI shielding building material
2019
Abstract In this investigation, and for the first time, pyrolysed sustainable cork was used to produce waste-based geopolymer-cork composites with enhanced electromagnetic interference (EMI) shielding properties. The influence of the pyrolysed cork amount and the geopolymer porosity on the EMI shielding ability of the composites was studied. The maximum total shielding effectiveness (SET) values achieved by these novel building materials (−13.8 to −15.9 dB) are equal to any other reported geopolymer microwave (MW) absorbers over the X-band, despite containing much lower carbon content. In addition, our composites were produced using an industrial waste (biomass fly ash) as raw material and …
Taking the Advantage of Smartphone Apps for Understanding Information Needs of Emergency Response Teams’ for Situational Awareness: Evidence from an …
2016
In search and rescue (SAR) operation, a lot of information is being shared among different emergency response groups. However, one of the key challenges experienced by these rescue groups during SAR operation is obtaining the complete awareness of the situation from the shared information. Moreover, one of the key actions of rescue leaders is to get the needed information in order to coordinate effectively with other teams and perform well. So, in this study we conduct an indoor fire drill with the help of Smartphone application with two settings (without SmartRescue smartphone application and with SmartRescue smartphone application) to find out what type of information is mostly communicat…
Synthesis, characterization and study of covalently modified triazole LAPONITE® edges
2020
Abstract LAPONITE® (Lap) clay mineral was successful functionalized by triazole groups in a two steps procedure. First, the Lap edges were modified with 3-azidopropyltrimethoxysilane by traditional heating and microwave irradiation. Microwave irradiation allowed us to obtain high loading onto the Lap edges in lower times compared to those obtained through conventional method. Afterwards, the triazole moieties were obtained by reaction between azido functionalized Lap and propargyl alcohol. The successful functionalization of Lap was proved by thermogravimetric analysis, FT-IR spectroscopy, dynamic light scattering and ζ-potential measurements. Finally, the effects of the surface modificatio…
Minimum Leading Edge Protection Application Length to Combat Rain-Induced Erosion of Wind Turbine Blades
2021
Leading edge erosion (LEE) repairs of wind turbine blades (WTBs) involve infield application of leading edge protection (LEP) solutions. The industry is currently aiming to use factory based LEP coatings that can applied to the WTBs before they are shipped out for installation. However, one of the main challenges related to these solutions is the choice of a minimum LEP application length to be applied in the spanwise direction of the WTBs. Generally, coating suppliers apply 10–20 m of LEP onto the blades starting from the tip of the blade using the “rule of thumb”, and no studies in the literature exist that stipulate how these LEP lengths can be calculated. In this study, we extend the sc…
Numerical prediction of ventilated planing flat plates for the design of Air Cavity Ships
2017
In recent years, a great world issue is the respect for the environment. Each researcher, in his competence field, proposes new technologies and new approaches in order to reduce the environmental impact of a product or of an industrial process. In the naval field, the main way in order to reduce the environmental impact of the ship during the navigation is the reduction of the drag resistance and so the reduction of requested power. There are many ways in order to obtain a reduction of drag. This paper investigates, with a preliminary numerical study by means of Computational Fluid Dynamics (CFD), the Air Cavity Ships technology (ACS). A first part of the paper concerns the study of the ri…
Flexural behavior of external beam-column reinforced concrete assemblages externally strengthened with steel cages
2016
In this paper, an experimental study referring to the flexural behavior of full-scale external beam-column joints externally strengthened with steel angles and strips and subjected to cyclic reversal loading is presented. One control specimen and five other specimens having the same characteristics as the control specimen but strengthened with steel angles and strips along beams and columns, and characterized by different configurations of strengthening in the critical regions, were tested. The control specimen was designed with a weak column and strong beam to reproduce the most common cases of old frame structures in the Mediterranean area, which were designed only for gravity loads and a…