Search results for "Structural engineering"
showing 10 items of 1998 documents
Comparison of tritium measurement techniques for a laser cleaned JET tile
2014
Abstract Over the last 7–8 years, two quantitative analyzing methods—accelerator mass spectrometry (AMS) and full combustion (FC) followed by scintillation detection have been applied for determining the tritium activity concentrations in JET divertor tiles. These methods have two main differences – the range of detection and the spatial resolution – and are thus complementary. However, these differences can also complicate the comparison of the two techniques for typical JET divertor samples. Therefore a cross comparison exercise for tritium measurements was performed between the two methods using specially produced identical standard samples. The cross comparison measurements were perform…
Effectiveness of isolated vertical extension of masonry buildings as nonconventional TMD
2023
In this paper, the strategy of Intermediate Isolation System (IIS) is proposed for the vertical extension of an aggregate of masonry buildings located in Pozzuoli, south Italy. The effectiveness of IIS working as a nonconventional Tuned Mass Damper (TMD) for the existing construction is assessed in terms of reduction of seismic demand and damage in the masonry structure undergoing inelastic deformation under seismic input. For this aim, a general step-by-step procedure is first defined and then applied to the case study building. In particular, the characterization of dynamic behaviour and seismic capacity of the building aggregate is first addressed through modal and push over analyses. El…
Closure to “New Theoretical Solution of Stage-Discharge Relationship for Slit Weirs” by Vito Ferro and Ismail Aydin
2018
In this paper, the flow-process of a slit weir was analyzed on the basis of a theorem of dimensional analysis and incomplete self-similarity theory. The theoretically deduced stage-discharge formula then was calibrated using experimental data obtained for a ratio between the weir and the channel width, ranging from 0.05 to 0.25. The deduced stage-discharge relationship allowed measuring discharge values characterized by errors that, for 98% of the measured values, were less than or equal to +/- 5%. The performance of the proposed theoretical stage-discharge formula also was improved by introducing the Reynolds number (for 98.5% of the measured values the error was less than or equal to +/- …
A closed-form solution for natural frequencies of thin-walled cylinders with clamped edges
2016
Abstract This paper presents an approximate closed-form solution for the free-vibration problem of thin-walled clamped–clamped cylinders. The used indefinite equations of motion are classic. They derive from Reissner׳s version of Love׳s theory, properly modified with Donnell׳s assumptions, but an innovative approach has been used to find the equations of natural frequencies, based on a solving technique similar to Rayleigh׳s method, on the Hamilton׳s principle and on a proper constructions of the eigenfuctions. Thanks to the used approach, given the geometric and mechanical characteristics of the cylinder, the model provides the natural frequencies via a sequence of explicit algebraic equat…
A correction method for dynamic analysis of linear continuous systems
2005
A method to improve the dynamic response analysis of continuous classically damped linear system is proposed. As in fact usually, following a classical approach, a reduced number of eigenfunctions are accounted for and the response is evaluated by integrating the uncoupled differential equations of motion in modal space, neglecting the contribution of high frequency modes (truncation procedure). Here, starting from the given system, it is proposed to set up two differential equations governing the motion of two new continuous systems: the first one contains only the first m non-zero eigenvalues of the given system and the second one contains the remainder non-zero infinity - m eigenvalues. …
Branch-and-Cut-and-Price for the Vehicle Routing Problem with Time Windows and Convex Node Costs
2019
Two critical yet frequently conflicting objectives for logistics and transportation service companies are improving customer satisfaction and reducing transportation cost. In particular, given a network of customer requests with preferred service times, it is very challenging to find vehicle routes and service schedules simultaneously that respect all operating constraints and minimize the total transportation and customers’ inconvenience costs. In this paper, we introduce the vehicle routing problem with time windows and convex node costs (VRPTW-CNC), in which we model each customer’s inconvenience cost as a convex function of the service start time at that customer. The VRPTW-CNC combine…
Vertical integration and exclusivities in maritime freight transport
2011
A key recent theme in maritime freight transport is the involvement of shipping lines in terminal management. Such investments are costly but allow liners to provide better service. Most of these new terminals are dedicated terminals but some are non-exclusive and let rivals access them for a fee. In this paper, we show that a shipping line that builds its own terminal finds it strategically profitable (i) to continue routing part of its cargo through the open port facilities, and (ii) to keep its terminal non-exclusive. In this way, the liner investor pushes part of the rival's freight from the open to the new terminal. Besides, under non-exclusivities, the shipping lines offer a wider var…
Vehicle scheduling for rental-with-driver services
2021
Abstract In this paper, we introduce a new vehicle scheduling problem (VSP) with driver consistency faced by rental-with-driver companies. A weekly time-horizon is considered and a set of potential customers, each one associated with a list of required tasks, is assumed. The company can choose to accept or reject a customer, but if accepted, all required tasks must be performed by the same driver. A profit is associated with each customer. The goal is to maximize the company’s total profit, by respecting a list of daily and the weekly drivers’ workload limitations imposed by drivers’ contracts. We propose a mathematical formulation of the problem and design an exact solution method based on…
Development of a Design Procedure for Bending Operations
1999
Springback can be considered as one of the most important shape defect in sheet stamping. Such effect results relevant even when simple bending operations are taken into account. In the paper the authors present a design procedure able to provide the proper value of the punch stroke to be applied in order to compensate for elastic springback. In particular two approaches have been followed: firstly an inverse design technique has been utilized in order to find out the response function governing the investigated phenomenon; furthermore neural network techniques have been applied in order to represent the logical link between the input data and the aimed output, i.e. the proper punch stroke …