Probabilistic Computations of Downtime for Inland Shipping in the Second Maasvlakte

2002 ◽  
Author(s):  
D. P. Hurdle ◽  
J. Onassis ◽  
J. J. Veldman
Keyword(s):  
Computational Methods ◽  
Structural Damage ◽  
Failure Modes ◽  
High Wind ◽  
Risk Of Failure ◽  
Port Area ◽  
Excessive Intake ◽  
Wave Conditions

This paper deals with the accessibility for inland shipping to several alternatives for the extension of the Maasvlakte in the Port of Rotterdam (Maasvlakte 2). The accessibility is governed by the risks associated with high wind and wave conditions, which can cause structural damage to the ship, excessive intake of water and high loads in the coupling cables of push-barge units. This paper discusses the computational methods for the following aspects: wave conditions in the port area; risk of failure in several failure modes and total downtime. The use of interviews with the skippers of the inland ships is discussed. A summary of the results of the study is also presented.

scholarly journals Damage Detection in Fiber-Reinforced Foamed Urethane Composite Railway Bearers Using Acoustic Emissions

2020 ◽  
Vol 5 (6) ◽  
pp. 50 ◽  
Author(s):  
Pasakorn Sengsri ◽  
Chayut Ngamkhanong ◽  
Andre Luis Oliveira de Melo ◽  
Mayorkinos Papaelias ◽  
Sakdirat Kaewunruen
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Failure Modes ◽  
Acoustic Emissions ◽  
Numerical Data ◽  
Composite Beams ◽  
Fiber Reinforced ◽  
Traffic Demand ◽  
Three Point Bending ◽  
Railway Industry

To a certain degree, composite railway sleepers and bearers have been recently employed as a replacement for conventional timber sleepers. Importantly, attributed to the rise in traffic demand, structural health monitoring of track structural members is essential to improve the maintenance regime and reduce risks imposed by any structural damage. A potential modern technique for detecting damage in railway components by using energy waves is called acoustic emission (AE). This technique has been widely used for concrete structures in other engineering applications, but the application for composites is relatively limited. Recently, fiber-reinforced foamed urethane (FFU) composites have been utilized as railway sleepers and bearers for applications in the railway industry. Neither does a design standard exist, nor have the inspection and monitoring criteria been properly established. In this study, three-point bending tests were performed together with using the AE method to detect crack growth in FFU composite beams. The ultimate state behaviors are considered to obtain the failure modes. This paper is thus the world’s first to focus on damage detection approaches for FFU composite beams using AE technology, additionally identifying the load-deflection curves of the beams. According to the experimental results, it is apparent that the failure modes of FFU composite beams are likely to be in brittle modes. Through finite element method, the results were in good agreement with less than 0.14% discrepancy between the experimental and numerical data. The attractive insights into an alternative technique for damage assessment of the composite components will help railway engineers to establish structural monitoring guidelines for railway composite sleepers and bearers.

FAILURE MECHANISM OF SINGLE-LAYER CYLINDRICAL RETICULATED SHELLS UNDER EARTHQUAKE MOTION

2012 ◽  
Vol 12 (02) ◽  
pp. 233-249 ◽  
Author(s):  
XU-DONG ZHI ◽  
FENG FAN ◽  
SHI-ZHAO SHEN
Keyword(s):  
Failure Mechanism ◽  
Structural Damage ◽  
Failure Modes ◽  
Dynamic Instability ◽  
Single Layer ◽  
Dynamic Strength ◽  
Fuzzy Synthetic Evaluation ◽  
Strength Failure ◽  
Earthquake Motion ◽  
Structural Responses

In order to have a good understanding of the failure mechanism of single-layer cylindrical reticulated shells under earthquake motions, two failure modes, that is, dynamic instability and dynamic strength failure, are studied of single-layer cylindrical reticulated shells under earthquake motion. The accumulation of material damages that may accelerate failure of these shells under dynamic actions is considered. The relationships between the structural responses under the ultimate loads are investigated through a systematic simulation study that covers different parameters. A method is proposed for classification of failure modes of the shells, using the fuzzy synthetic evaluation theory and the structural responses of different sample studies. The effectiveness of the proposed method is proved through applications to some examples. Finally, a damage model is established for identification of different structural damage levels and for determination of the ultimate load for strength failure.

scholarly journals Investigation of an Air-Cushion Supported Solar Island

2018 ◽  
Author(s):  
Trygve Kristiansen ◽  
Petter Borvik
Keyword(s):  
Failure Modes ◽  
Preliminary Investigation ◽  
Circular Cross Section ◽  
Linear Potential ◽  
Air Leakage ◽  
General Behaviour ◽  
Supported Membrane ◽  
Flexible Mode ◽  
Air Cushion ◽  
Wave Conditions

A preliminary investigation of a low-weight carrying marine platform concept was conducted by means of experiments and approximate theories. The platform consists of a circular elastic tube with circular cross-section, covered with an air-supported membrane deck. A vertical skirt is added along the circumference of the model to avoid air-leakage. We refer to this concept as floating solar island. Solar islands have recently gained interest. The models were subjected to waves. Both regular and irregular wave tests were conducted. Tests with the absence of the membrane (floater only) were also conducted. The general behaviour and failure modes were investigated. Failure modes include over-topping with flooding as consequence, as well as out-of-water incidents and membrane wear with air leakage as consequence. A systematic variation of wave conditions revealed for which wave conditions flooding occured. Out-of-water incidents of the skirt were not observed. Vertical accelerations were measured at eight positions along the circumference of the model, and the heave, pitch and first flexible mode motions were re-constructed by modal theory. The modal responses were compared to theory based on linear potential flow assumption, both for the floater model only, and with simplified theory accounting for the air-cushion of the island in heave. The theory was able to predict the global behaviour reasonably well, although important discrepancies were observed. More detailed studies, involving experiments with more instrumentation and development of theory, must be conducted in case deeper understanding of this relatively complex, hydro-elastic concept is needed.

Overview of Structural Life Assessment and Reliability, Part VI: Crack Arresters 1

2016 ◽  
Vol 32 (02) ◽  
pp. 71-98
Author(s):  
R. A. Ibrahim
Keyword(s):  
Stress Intensity Factor ◽  
Fracture Mechanics ◽  
Composite Structures ◽  
Structural Damage ◽  
Failure Modes ◽  
Life Assessment ◽  
Stress Concentrations ◽  
Ship Structures ◽  
Probabilistic Description ◽  
Damage Process

Structural life assessment periodically evaluates the state and condition of a structural system and provides recommendations for possible maintenance actions or the end of structural service life. It is a diversified field and relies on the theories of fracture mechanics, fatigue damage process, probability of failure, and reliability. With reference to naval ship structures, their life assessment is not only governed by the theory of fracture mechanics and fatigue damage process, but by other factors such as corrosion, grounding, and sudden collision. The purpose of this series of review articles is to provide different issues pertaining to structural life assessment of ships and ocean structures. Part I deals with the basic ingredients of the theory of fracture mechanics, which is classified into linear elastic fracture mechanics and elasto-plastic fracture mechanics. The amount of energy available for fracture is usually governed by the stress field around the crack, which is measured by the stress intensity factor. The value of the stress intensity factor, which depends on the loading mode, is evaluated by different methods developed by many researchers. The applications of the theory of fracture mechanics to metallic and composite structures are presented with an emphasis to those used in marine structures. When the inertia of relatively large pieces of a structure is large enough that the correct balancing of the energy of fracture requires the inclusion of kinetic energy, then the dynamic nature of fracture dominates the analysis. For a crack that is already propagating, the inertial effects are important when the crack tip speed is small compared with the stress wave velocities. This fact has been realized in the theory of fracture mechanics under the name of dynamic fracture and peridynamic. In essence, peridynamic replaces the partial differential equations of classic continuum theories with integro-differential equations as a tool to avoid singularities arising from the fact that partial derivatives do not exist on crack surfaces and other singularities. A brief overview of fracture dynamics and peridynamics together with damage mechanisms in composite structures is presented. The limitations of fracture mechanics criteria are also discussed. Life assessment of ship structures depends on the failure modes and the probabilistic description of failure, which are addressed in Part II. Life assessment of ship structures depends on the failure modes and the probabilistic description of failure. In view of structural parameter uncertainties, probabilistic analysis requires the use of reliability methods for assessing fatigue life by considering the crack propagation process and the first passage problem, which measures the probability of the exit time from a safe operating regime. The main results reported in the literature pertaining to ship structural damage assessments resulting from to slamming loads, liquid sloshing impact loads of liquefied natural gas in ship tankers, and ship grounding accidents, and collision with solid bodies are discussed in Part III. Under such extreme loadings, structural reliability will be the major issue in the design stage of ocean structures. The treatment of extreme loading on ship structures significantly differs from those approaches developed by dynamicists. Environmental effects on ship structures play a major factor in the life assessment of ocean systems. In particular, these effects include corrosion and hydrogen embrittlement. Part IV is devoted to a ship's life assessment resulting from corrosion and hydrogen embrittlement. Because structural components made from aluminum and its alloys are vital to the ship and aerospace industries, the influence of environment on aluminum structures and the means of corrosion control and monitoring in both aluminum and nonaluminum metals are presented. Hybrid ships consist of a stainless steel advanced double-hull center section, to which a composite material bow and/or stern is attached. Such structures require strong joints between the composite and the steel parts. Some of the difficulties with joining composites and metal are related to the large difference in mechanical properties such as stiffness, coefficient of thermal expansion, etc., between the adherents and the large anisotropy of composites. Such differences generally lead to large stress concentrations and weak joints. Fatigue crack growth, stress concentrations resulting from details, joints, and fasteners are addressed in Part V. Fatigue improvement in welded joints is considered one the major tasks of this part. Brittle fracture of hull structures causes serious structural damage and this motivated the ship structure community to develop some means to prevent brittle cracks from occurring. The basic principle behind the use of a crack arrester is to reduce the crack-driving force below the resisting force that must be overcome to extend a crack. The crack arrestor can be as simple as a thickened region of metal or may be constructed of a laminated or woven material that can withstand deformation without failure. Part VI provides different approaches of passive crack control in the form of crack arresters to stop crack propagation before it spreads over a structure component. Crack arresters used in ship structures and pipelines are described for both metal and composite materials. This six-part review article is by no means exhaustive and is based on over 1800 references. It does not address the structural health monitoring, which constitutes a major task in the structural diagnostic process.

Influence of Arctic seawater exposure on the flexural behavior of woven carbon/vinyl ester composites

2017 ◽  
Vol 21 (3) ◽  
pp. 1190-1208 ◽  
Author(s):  
R Garcia ◽  
AG Castellanos ◽  
P Prabhakar
Keyword(s):  
Flexural Strength ◽  
Vinyl Ester ◽  
Structural Damage ◽  
Failure Modes ◽  
Sea Water ◽  
Water Saturation ◽  
Flexural Modulus ◽  
Flexural Behavior ◽  
Failure Behavior ◽  
Material System

In this paper, the adverse effects of sea water environment and arctic temperatures on woven carbon fiber/vinyl ester composites are explored in the form of moisture uptake, impact on flexural modulus, strength, and structural damage. The research presented here attempts to relate failure modes to the flexural behavior of these composites exposed to three key environmental conditions: sea water, arctic temperature and combined sea water/arctic condition. Sea water saturation in general degrades the flexural strength up to ≈19.45%. Microstructures of dry and saturated samples are compared using scanning electron microscopy, where a saturated surface with distinctive hue for wet samples is observed as compared to a rough (parched) surface in the dry samples, implying large concentrations of sea water in a thin layer at the specimen boundaries. Arctic exposure and combined condition on these laminates increase the flexural strength by about 23.1% and 36.2%, respectively. However, they tend to shift the post peak behavior from progressive to brittle-type failure as compared to dry samples, which is attributed to matrix and fiber embrittlement in the material system caused by exposure to low temperature. Further, relatively large variations are observed in the flexural strength values of samples exposed to the combined condition (sea water saturated + arctic), which can be attributed to the freezing of sea water that was entrapped during sea water saturation. Variation in the quantity and location of sea water entrapped can alter the flexural strength significantly. Due to the aforementioned flexural responses and failure behavior observed in woven carbon/vinyl ester composites exposed to sea water arctic environment, special consideration is required while designing critical load bearing components in naval applications to avoid possible catastrophic structural failure.

scholarly journals EASI: An Air–Sea Interaction Buoy for High Winds

2014 ◽  
Vol 31 (6) ◽  
pp. 1397-1409 ◽  
Author(s):  
W. M. Drennan ◽  
H. C. Graber ◽  
C. O. Collins ◽  
A. Herrera ◽  
H. Potter ◽  
...  
Keyword(s):  
Surface Waves ◽  
Deep Water ◽  
Lower Atmosphere ◽  
Upper Ocean ◽  
High Wind ◽  
Wave Conditions ◽  
High Winds

Abstract This paper describes the new Extreme Air–Sea Interaction (EASI) buoy designed to measure direct air–sea fluxes, as well as mean properties of the lower atmosphere, upper ocean, and surface waves in high wind and wave conditions. The design of the buoy and its associated deep-water mooring are discussed. The performance of EASI during its 2010 deployment off Taiwan, where three typhoons were encountered, is summarized.

Integrating TOPSIS and DEMATEL Methods to Rank the Risk of Failure of FMEA

2014 ◽  
Vol 13 (06) ◽  
pp. 1229-1257 ◽  
Author(s):  
Kuei-Hu Chang ◽  
Yung-Chia Chang ◽  
Yu-Tsai Lee
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Iso 9000 ◽  
Decision Makers ◽  
Risk Priority Number ◽  
Effect Analysis ◽  
Analysis Techniques ◽  
Risk Of Failure ◽  
Quality Certification ◽  
Order Preference

Failure mode and effect analysis (FMEA) is one of the risk analysis techniques recommended by international quality certification systems, such as ISO 9000, ISO/TS 16949, CE, and QS9000. Most current FMEA methods use the risk priority number (RPN) value to evaluate the risk of failure. The RPN value is the mathematical product of the three parameters of a failure mode that is rated between 1 and 10 in terms of its severity (S), occurrence (O), and detection (D), respectively. However, the RPN method has been found with three main drawbacks: (1) high duplicate RPN values, (2) failure to consider the ordered weights of S, O, and D, and (3) failure to consider the direct and indirect relationships between the failure modes and causes of failure. Therefore, this paper integrates the technique for order preference by similarity to ideal solution (TOPSIS) and the decision-making trial and evaluation laboratory (DEMATEL) approach to rank the risk of failure. A case of an inlet plate ring that has been drawn from a professional mechanical factory is presented to further illustrate the proposed approach. After comparing the result that was obtained from the proposed method with the conventional RPN and DEMATEL methods, it was found that the proposed method can resolve the abovementioned RPN ranking issues and give a more appropriate risk assessment than other listed approaches to provide valuable information for the decision makers.

Evaluation of Tsunami Wave Loads Acting on Walls of Confined-Masonry-Brick and Concrete-Block Houses

2014 ◽  
Vol 9 (6) ◽  
pp. 976-983 ◽  
Author(s):  
Gaku Shoji ◽  
◽  
Hirofumi Shimizu ◽  
Shunichi Koshimura ◽  
Miguel Estrada ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Structural Damage ◽  
Failure Modes ◽  
Tsunami Wave ◽  
Concrete Block ◽  
Wave Loads ◽  
Wave Load ◽  
Confined Masonry ◽  
Wave Pressure ◽  
Horizontal Wave

Damage to confined-masonry-brick or concrete-block house was assessed for being subjected to a tsunami wave load. This study was prompted by recent three tsunamis – one during 2001 on the Near Coast of Peru, one in 2009 in the Samoa Islands, and one in 2010 in Maule, Chile. We analyzed 13 damaged walls from 10 single-storey houses located near the coastline. We focused on evaluating the tsunami wave pressure distribution on house walls. Based on the formula proposed by Asakura et al. (2000) to evaluate tsunami wave pressure distribution on a structural component located on land behind on-shore structures, which is used for designing a tsunami evacuation building, we identify the values of horizontal wave pressure indexain Asakura’s formula for walls and discuss the boundary value ofaat which a wall presents structural damage, such as in collapse and cracking failure modes.

Experimental Investigation of Residual Ultimate Strength of Damaged Metallic Pipelines

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Jie Cai ◽  
Xiaoli Jiang ◽  
Gabriel Lodewijks ◽  
Zhiyong Pei ◽  
Ling Zhu
Keyword(s):  
Ultimate Strength ◽  
Structural Damage ◽  
Large Scale ◽  
Failure Modes ◽  
Bending Strength ◽  
Metal Loss ◽  
Pipe Surface ◽  
Comparison Results ◽  
Mechanical Interference ◽  
Bending Capacity

The ultimate strength of metallic pipelines will be inevitably affected when they have suffered from structural damage after mechanical interference. The present experiments aim to investigate the residual ultimate bending strength of metallic pipes with structural damage based on large-scale pipe tests. Artificial damage, such as a dent, metal loss, a crack, and combinations thereof, is introduced to the pipe surface in advance. Four-point bending tests are performed to investigate the structural behavior of metallic pipes in terms of bending moment–curvature diagrams, failure modes, bending capacity, and critical bending curvatures. Test results show that the occurrence of structural damage on the pipe compression side reduces the bending capacity significantly. Only a slight effect has been observed for pipes with damage on the tensile side as long as no fracture failure appears. The possible causes that have introduced experimental errors are presented and discussed. The test data obtained in this paper can be used to further quantify damage effects on bending capacity of seamless pipes with similar D/t ratios. The comparison results in this paper can facilitate the structural integrity design as well as the maintenance of damaged pipes when mechanical interference happens during the service life of pipelines.

scholarly journals Development of parametric seismic fragility curves for historical churches

2021 ◽  
Author(s):  
Alessandra Marotta ◽  
Domenico Liberatore ◽  
Luigi Sorrentino
Keyword(s):  
Seismic Performance ◽  
Structural Damage ◽  
Seismic Vulnerability ◽  
Failure Modes ◽  
Fragility Curves ◽  
Central Italy ◽  
Ratio Test ◽  
Main Shocks ◽  
Structural Details ◽  
Masonry Churches

AbstractFor both spiritual and cultural reasons, churches are an essential part of the historical heritage of several countries worldwide, including Europe, Americas and Australasia. The extreme damage that occurred during the 2016–2017 Central Italy seismic swarm highlighted once again the noteworthy seismic vulnerability of unreinforced masonry churches, which exhibited several collapses and caused uncountable losses to the Italian artistic heritage. The seismic performance of 158 affected buildings was analyzed in the aftermath of the main shocks. The failure modes activated by the earthquakes were identified making reference to the local mechanisms currently considered in Italy for post-seismic assessment of churches. The structural damage of the investigated buildings, related to 21 mechanisms rather than to an overall global response, was explained resorting to empirical statistical procedures taking into account ground motion intensity and structural details that can worsen or improve the seismic performance. Finally, parametric fragility curves were derived selecting those structural details that mostly influence the damage by means of the likelihood-ratio test. Developed models can be used in future territorial-scale scenario or risk analyses.

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