This study concentrates on a comparison between steel plate and stiffened panels subject to localised corrosion. A finite element analysis is used to investigate the effect of random corrosion on the compressive strength capacity of marine structural units. Variables include the extent of corrosion; slenderness ratio and aspect ratio. A corrosion prediction model is incorporated to determine the thickness reduction with time. Corrosion-induced volume loss results in a greater reduction of ultimate strength for slender plates compared to stiffened panels, up to 45%, showing the structural element selection can strongly influence the accuracy of the estimated corrosion damage effect.

Influence of corrosion on the ultimate compressive strength of steel plates and stiffened panels

The State of Bahia has one of the largest port complexes in Brazil, that consists of public ports and private use terminals. One of which is specialized with a cargo carrying capacity of about 530 thousand TEUs (Twenty-foot Equivalent Unit) per year. On the other hand, the container terminal at the port of Genoa, Italy, has a similar capacity but has been performing better than the Brazilian one. The present study evaluates the differences and similarities between these ports, in the context of engineering, environmental sustainability and some topics of the port regulatory framework that can influence productivity. Based on the arrival and service rates of the ships and their respective probability distributions, a mathematical model of queuing theory was developed that indicates the port occupation rate, the time and the average number of ships in the queue, in a process with which one can assess the environmental impact of these terminals. (naval-port infrastructure and queuing theory) and in environmental sustainability, as well as in some points of the regulatory framework and logistical infrastructure of both countries that can influence and reveal the competitiveness of these ports. Based on vessel arrival and service rates and their consequent probability distributions, in addition to other constraints, the queuing model reveals the time and average number of ships in process, the port occupation rate, and the expected probability of this finding variable, may provide a possibility of fine payments for delay in services, thus serving as the efficiency indicators of port operation. The results obtained here, and their interpretations, are limited to the time of their respective data collection, as well as to the reliability of information that was possible to obtain at the time of the technical visits and professional meetings held. They are also limited to the consultations made to the electronic pages of the terminals and institutions that control local port operations. The present work is in the context of other researches already carried out. Camelo et al. (2010), used queuing theory to simulate the behavior of the row of iron ore vessels in the port of Ponta da Madeira, Brazil, with the aid of the Arena® software and found high berth occupation rates, recommending investments in the expansion of its capacity to meet the expectations of growing demand for ores in the world market. In this same direction, Schoreder (2014) simulated the operational behavior of the container terminal at the port of Durban, South Africa, based on the operation of the queue system of the container terminal at the port of Rotterdam from the logic of model construction simulated

Progress in Maritime Technology and Engineering : Proceedings of the 4th International Conference on Maritime Technology and Engineering (MARTECH 2018), May 7-9, 2018, Lisbon, Portugal

The investigation of wetdeck slamming phenomenon is a challenging Fluid-Structure Interaction (FSI) problem for both experimental and numerical analysis, requiring detailed design and structural assessment of the physical model. The focus of this paper is to document the design approach and the testing effort devoted to provide a reliable and well identified physical model before the towingtank tests were carried out for giving key insights into the wetdeck load and responses as well as an FSI validation dataset for numerical solvers. Thus, one of the main objectives is reducing the uncertainty linked to the modeling of the multi-hull structure by performing a series of both static and dynamic characterization tests on the as built catamaran model. The insight gained from this test campaign will be used to update the structural models coupled within the FSI solvers to increase the accuracy of the predicted hydrodynamic loading. Among FSI problems still receiving positive attention in ship and offshore engineering, the accurate prediction of complex loading and responses on multi-hull vessels is particularly demanding, since it involves two-way coupling of the deck structure with the flow impinging on it. Currently, there is a gap in available experimental FSI data related to this problem that can be used for numerical solver validation. Current FSI data sets are severely limited by the uncertainties associated with the experimental setups. Furthermore, though segmented model tests have become more feasible and popular for monohulls, not many experimental campaigns (Hermundstad et al. 1995, Kyyro & Hakala 1997, Cheng, F. 1997) exist for segmented catamarans that provide both global and local loads and hull responses. The only systematic investigation on elastically scaled catamarans was carried out by Lavroff et al. (2007, 2013). Dessi et al. (2016) have already illustrated the preliminary experimental results on an elastically scaled model of a SWATH aimed to accurately depict the wave loading and structural response from seakeeping tests. In the present paper the focus is instead on the structural tests performed for the physical model qualification with an extended account of the dry and wet vibration mode identification of the entire catamaran.

Progress in the Analysis and Design of Marine Structures : Proceedings of the 6th International Conference on Marine Structures (MARSTRUCT 2017), May 8-10, 2017, Lisbon, Portugal

Experimental study on compressive behavior of GFRP stiffened panels using digital image correlation

The behaviour and ultimate strength of locally damaged plate panels is investigated in this study. The damage is in the form of a local imperfection and represents a dent that could be caused by a fall or strike of an object. Panels are made of nine identical plates – three plates transversally and three longitudinally – and only one of the plates is damaged. The influence of several parameters has been studied to establish their interaction with the presence of the local dent. The main focus, is however the influence of the adjacent intact plates. The large panel is compared with smaller transverse model made of three plates and with a single plate model in order to evaluate the effects of adjacent plates and define the minimum size of the model necessary to obtain proper results.

Ultimate strength of locally damaged panels

Unstiffened plates are integral part of ship structures, offshore oil platforms, lock gates and floating docks. Openings are provided in these plates for access and maintenance. Provision of opening influences the ultimate strength of plate elements. In this paper the effect of increase in the size of rectangular opening along the loading direction on the ultimate strength is determined using nonlinear finite element analysis. A general purpose finite element software ANSYS is used for carrying out the study. The software is validated for the ultimate strength of unstiffened plate under axial compression. A parametric study is done for different plate slenderness ratios and by varying the area ratio of opening to plate to determine the effect of ultimate strength on the size of rectangular opening. It is found that increase in area ratio along the loading direction decreases the ultimate strength. The variation in ultimate strength varies linearly for plate slenderness ratio less than 2.23 and varies nonlinearly for plate slenderness ratio beyond 2.23 for area ratio ranging between 0.02 - 0.18. Based on nonlinear regression analysis, a design equation is proposed for square plate with rectangular opening under axial compression. Keywords: Unstiffened Plate, Ultimate Strength, Rectangular Opening, Axial Compression, Design Equation DOI: 10.3329/jname.v4i1.913 Journal of Naval Architecture and Marine Engineering 4(2007) 15-26

https://www.researchgate.net/profile/M_Kumar9/publication/245564001_Ultimate_strength_of_square_plate_with_rectangular_opening_under_axial_compression/links/53f478810cf2888a7490fd5f.pdf

Ultimate strength of square plate with rectangular opening under axial compression

Stiffened panels in ships and offshore oil platforms are provided with circular openings for repair, access and maintenance. This paper presents the numerical study carried out on the ultimate strength of stiffened panel with central circular opening subjected to axial load, lateral load and a combination of axial and lateral loads. Ultimate strength of the panel was evaluated considering both geometric and material non-linearities using FEA software ANSYS. Plates of varied widths and open section unequal angle stiffeners covering plate and column slenderness ratios in the practical range of 1.0–4.5 and 0.32–1.00, respectively, keeping the opening ratio equal to 1.0 are the parameters considered in this study. On the basis of the study, interaction curves were developed for normalised axial load and normalised lateral load. The developed interaction curves for stiffened panels with angle stiffeners and circular opening were found to be non-linear for lower plate slenderness ratio up to 2.0 and for the ran...

M. Suneel Kumar

Papers

Ultimate strength of square plate with rectangular opening under axial compression

Interaction curves for stiffened panel with circular opening under axial and lateral loads

Ultimate strength of stiffened plates with a square opening under axial and out-of-plane loads

Seismic performance of special concentric steel braced frames

Ultimate Strength of Ship Plating under Axial Compression