Horizon 2020 Marie Skłodowska-Curie Innovative Training Network

Giulia Milana

BSc, MSc
Home/Giulia Milana
Giulia Milana 2019-01-11T23:06:43+00:00
Early Stage Researcher
Lloyd’s Register EMEA (United Kingdom)

Project 6: Residual life assessment and management of ship unloaders

Click on the icons for Giulia’s email, blog and Linkedin profile

Research Interests:

Structural engineering; Steel structures; Finite element analysis; Structural analysis and design; Sustainability; Dynamic analysis

Biography:

Giulia Milana earned a Master’s degree in structural engineering from University of Rome ‘La Sapienza’ in 2014, with a thesis entitled ‘Sustainability concepts in the design of high-rise buildings: the case of diagrid systems’.

Following graduate studies, she did an internship with StroNGER S.r.l. focusing on sustainable structural schemes for high-rise steel buildings and in particular Finite Element Element Method models and robustness analysis.

At the same time she developed some aspects of her Thesis and elaborated on some research papers, presenting her work at some international conferences.

Before joining TRUSS ITN in September 2015, she had published 1 journal and 4 conference papers. A summary of her research highlights and training, dissemination and outreach activities in TRUSS  other than network-wide events, is provided in the pdf below, followed by more detailed info on her research outputs.

ESR6_Summary

Research Outputs:

  • Milana, G., Olmati, P., Gkoumas, K. and Bontempi, F. (2015), “Ultimate capacity of diagrid systems for tall buildings in the nominal configuration and the damaged state”, Periodica Polytechnica Civil Engineering, paper 7795. [DOI]


Publications in TRUSS

Conference contributions
In the current paper, the impact of the hoisting operations, on the dynamic response of the lifting boom of a ship unloader, are taken into consideration. The lifting boom is used to carry out transient dynamic analysis, since it was recognized to be the single most representative element for studying the dynamic response of these structures. The response of the lifting boom was the result of dynamic analysis comprising two components: the structure (representing the waterside portion of the boom), and the applied load (expressed as different hoisting force profiles). A comparison between the different force profiles was carried out, in order to identify the parameters that mostly influence the dynamic behavior of the structure during a loading cycle. Furthermore, a baseline case based on pseudo-static analysis (as standard recommendation FEM 1987) was introduced and comparisons carried out in terms of vertical displacement and bending moments.
Here, the TRUSS (Training in Reducing Uncertainty in Structural Safety) ITN (Innovative Training Network) Horizon 2020 project (http://trussitn.eu, 2015-19) demonstrates how accuracy of residual life assessment predictions can be improved by achieving a good agreement between measured and predicted dynamic responses of a crane structure. Existing records of measured strain data are often missing information such as the weight of the payload, the hoisting speed and acceleration that are relevant for structural assessment purposes. This paper aims to reduce uncertainties associated to the recorded data in an aged grab ship unloader by comparing measured and non-linear transient finite element analyses results for a loading/unloading cycle. The speed pattern is determined from a best match to the measured record. The moving load consisting of ‘trolley + grab + payload’ is modelled with parameters that are derived from minimizing differences between measured and simulated responses. The determination of these loading parameters is central to accurately assess the remaining life of ship unloaders. -> Link to full text in academic repository

There is multitude of models available to assess structural safety based on a set of input parameters. As the degree of complexity of the models increases, the uncertainty of their output tends to decrease. However, more complex models typically require more input parameters, which may contain a higher degree of uncertainty. Therefore, it becomes necessary to find the balance that, for a particular scenario, will reduce the overall uncertainty (model + parameters) in structural safety. The latter is the objective of the Marie Skłodowska-Curie Innovative Training Network titled TRUSS (Training in Reducing Uncertainty in Structural Safety) funded by the EU Horizon 2020 research and innovation programme (http://trussitn.eu). This paper describes how TRUSS addresses uncertainty in: (a) structural reliability of materials such as basalt fiber reinforced polymer, (b) testing techniques in the assessment of concrete strength in buildings, (c) numerical methods in computing the non-linear response of submerged nuclear components subjected to an earthquake, (d) estimation of life of wind turbines, (e) the optimal inspection times and management strategies for ships, (f) characterization of the dynamic response of ship unloaders and (g) the relationship between vehicles fuel consumption and pavement condition.-> Link to full text in repository

Container cranes represent an important link in the maritime transport system. Assessment of residual life for such cranes is important both in terms of safety and cost of repair and maintenance. These cranes usually have a hoisting trolley system which can move along the boom for lifting, carrying and lowering the payload, loading/unloading vessels in the harbour. This paper investigates the dynamic response of the lifting boom using a non-linear finite element analysis. A number of such moving trolley systems, with different degrees of complexity, are modelled to assess the impact of their influence on the boom dynamic response parameters. Results from the finite element analysis are compared to a pseudo-static analysis and are presented in terms of a Dynamic Response Factor (DRF).-> Link to full text in repository

This paper highlights the impact of dynamic amplification factors in remaining fatigue life assessment of ship unloaders. In practice, the widely accepted procedure for these structures is to carry out a fatigue life assessment envisages: (1) carrying out static analysis, (2) taking into account dynamics via the application of dynamic amplification factors, and (3) applying Miner’s rule. This factor, provided by the standard, is applied to the structure as a whole without considering the vibration of each structural member individually. This paper characterizes the dynamic behavior of each element using location-based dynamic amplification factors estimated from measurements. This caters for a more accurate assessment of the structure, whilst maintaining the simplicity of the standard procedure. [DOI] -> Link to full text in repository

This paper reviews methodologies for fatigue analysis with emphasis on ship unloaders. Maintaining the performance of ship unloaders at a satisfactory level is essential for any port’s operation in order to comply with the global demand of shipping and trading. Ship unloaders are subject to alternating operational loadings and to adverse environmental conditions, and as a result, they show a rapid rate of deterioration that makes them susceptible to failure by cumulative damage processes such as corrosion and fatigue. The purpose of this paper is to review key features of the most common methodologies for fatigue analysis and to underline the limitations and uncertainties involved. Finally, developments in reliability-based approaches are suggested for a more accurate fatigue assessment of ship unloaders. -> Link to full text in repository

This paper reviews the most common causes of failure in ship unloaders. The structural forms employed in the design of ship unloaders and the characteristics of the loads acting on these structures are introduced first. Then, typical failures including overloading, joint failure, cable breaking, corrosion and fatigue failure amongst others, are described. Fatigue failure is discussed in further detail. When assessing a ship unloader for fatigue, it is necessary to define the fatigue demand and the fatigue strength capacity of those structural details under investigation. The latter experiences stress cycles that accumulate over time until reaching a limit that leads to cracking. Loads and stresses need to be monitored to describe those cycles, and critical locations must be checked to prevent a catastrophic failure. -> Link to full text in repository