Search results for "Structural engineering"
showing 10 items of 1998 documents
Performance evaluation of directly photovoltaic powered DC PM (direct current permanent magnet) motor – propeller thrust system
2013
Photovoltaic (PV) powered directly coupled electro-mechanical system has wide applications (e.g. PV powered cooling fans in green houses, PV water pumping system, solar vehicles). The objective of this work is to analyse the operation of directly PV powered DC PM (direct current permanent magnet) motor – propeller system for selection of motor parameters. The performance of such system mainly depends on the incident solar radiation, operating cell temperature, DC motor and propeller load parameters. It is observed that the operating points of the PV DC PM motor – propeller system matches very closely with the maximum power points (MPPs) of the PV array, if the DC PM motor – propeller parame…
Modular device for determining forming limit curves – a cost effective aproach
2010
Abstract The paper presents the realising and functioning of a modular device for testing the formability of metal sheets. By using the device it is possible to realise experimentally the tests needed for drawing the forming limit curves using the Nakajima and Marciniak methods, but there can be also done researchs on deep-drawing. The results gathered from the tests were validated by numerical simulations using the finite element method. The device was designed at the Research Center for Metal Forming of the “Lucian Blaga” University of Sibiu and realised with the support of S.C. Uzina Mecanica Marsa – Sibiu
A new and simplified approach to assess the pavement surface micro- and macrotexture
2017
Abstract Road safety depends on pavement skid resistance and surface texture. Skid resistance mainly depends on micro-texture and macrotexture. Skid and texture measurements on samples, in the laboratory, at the preliminary stage of the design, would enhance the design in terms of timing, costs, and reliability. Consequently, this study aims at setting up and validating simple methods for assessing surface texture and skid resistance based on core/sample measurements. Experiments were carried out and predictive relationships were set up to explain and predict results. Under given conditions, miniaturised macro-and microtexture tests (modified EN 13036-1 and modified EN 13036-4, respectively…
Failure by corrosion in PC bridges: A case history of a viaduct in Italy
2016
Purpose The paper illustrates a viaduct collapse due to corrosion phenomena. Moreover, a contribution to the issues related to both the control of existing structures and design methods to be followed for the construction of new buildings is provided. Design/methodology/approach The objectives were achieved by in situ observations and numerical analyses. The effects of corrosion phenomena are investigated, and the progressive collapse analysis is provided to be helpful in this case. Findings The damages induced by corrosion phenomena have caused the collapse of the viaduct taken in to account. The performed numerical analyses were able to reproduce the effects of corrosion in terms of redu…
A microplane model for plane-stress masonry structures
2003
Publisher Summary For a refined nonlinear finite element analysis of masonry structures, an accurate constitutive model that is able to reproduce the desired phenomenological material features is required. Constitutive models for quasi-brittle materials, as plain concrete, have been proposed in the chapter, which allow to reproduce the very complex response in the two- or three-dimensional state of stress. Usually, the constitutive relations proposed are based on some appropriate extensions of elastic-plastic continuum models and more recently on continuum damage models. It has been observed that for these tensorial-based constitutive relations to be effective often require a large number o…
A feasibility study of some DSM enabling solutions in small islands: The case of Lampedusa
2017
Abstract The paper addresses the issue of the transition from a traditional electrical system without automation to a newer active and smart system allowing the possibility of implementing Demand Side Management policies, for little islands not supplied by the main grid. In particular, the paper focuses on two main topics related to the definition of: • an effective control, monitoring and communication system as a tool for the full exploitation of the opportunities given by Demand Response policies; • some solutions for the automation of the end-users’ electrical installations, in order to offer to the utility flexibility to be used for the improvement of the generation and distribution ef…
The cost of green roofs disposal in a life cycle perspective: covering the gap.
2012
Abstract This study is aimed at providing a contribution in overcoming the current gap, especially in Life Cycle Costing (LCC) and Benefit – Cost (BCA) analyses, due to the lack concerning the green roof disposal costs. Therefore, we have applied to an actual extensive green roof the LCC methodology suggested by D. G. Woodward (that appears like one of the most formalized and generalizable), but we have extended the analysis to the disposal phase. This will allow a complete and proper application of the LCC methodology in order of achieving an economic accounting of this component through its life cycle. In this way, it is possible to achieve the complete evaluation of the “green roof” perf…
A GRASP algorithm for the container stowage slot planning problem
2016
This work presents a generalization of the Slot Planning Problem which raises when the liner shipping industry needs to plan the placement of containers within a vessel (stowage planning). State-of-the-art stowage planning relies on a heuristic decomposition where containers are first distributed in clusters along the vessel. For each of those clusters a specific position for each container must be found. Compared to previous studies, we have introduced two new features: the explicit handling of rolled out containers and the inclusion of separations rules for dangerous cargo. We present a novel integer programming formulation and a Greedy Randomized Adaptive Search Procedure (GRASP) to solv…
Cloudy with a Chance of Fuzzy: Building a Multicriteria Uncertainty Model for Construction Project Delivery Selection
2017
AbstractThe process of choosing a project delivery method is infused with cognitive uncertainties associated with the decision maker. Fuzzy uncertainties arise because of imprecise understanding and subsequent representation of these uncertainties by the decision maker, whereas random uncertainties arise from variance of these imprecisions. Since there are no well-defined rules for spontaneous decisions, in order to be consistently confident in the appropriateness of the chosen delivery method, a structured approach incorporating uncertainty is required. Previously unanswered questions such as (1) what are the sources of uncertainty in project delivery decisions, (2) how do decision makers …
Multicriteria evaluation of sustainable energy solutions for Colosseum
2017
Abstract Colosseum is a large office building in the capital region of Finland. The building owner operates on the highly competitive office rental market. With increasing emphasis on environmental responsibility, energy efficiency and sustainable energy solutions can provide competitive edge on the rental market. This study evaluates in terms of multiple criteria different alternatives to enhance the energy solutions of the building. The alternatives included different configurations of solar power, ground source heat, and roof constructions, along with district heating. Decision criteria included internal rate of return, energy efficiency, CO2 emissions, and attractiveness. Attractiveness…