Development of a Relationship Between Residual Ultimate Longitudinal Strength Versus Grounding Damage Index Diagram for Container Ships

2012 ◽  
Author(s):  
Do Kyun Kim ◽  
Han Byul Kim ◽  
Xiaoming Zhang ◽  
Preben Terndrup Pedersen ◽  
Min Soo Kim ◽  
...  
Keyword(s):  
Structural Damage ◽  
Damage Index ◽  
International Maritime Organization ◽  
Longitudinal Strength ◽  
Fire And Explosion ◽  
Damage Criteria

Various accidents such as grounding, collision, fire, and explosion commonly occur on operating ships. The structural damage caused by such accidents is often accompanied by casualties and serious pollution. Therefore, an accidental risk-based approach that is in line with the goal-based standard of the International Maritime Organization is being developed in the literature. In the present paper, the residual ultimate longitudinal strength versus grounding damage diagram (R-D diagram) for container ships is established as per the method of Paik et al. [1]. The proposed R-D diagram should be useful for defining acceptance damage criteria and making rapid salvage plans or rescue schemes for container ships that have sustained a grounding accident.

A New Method for Assessing the Safety of Ships Damaged by Grounding

2012 ◽  
Vol 154 (A1) ◽  
Keyword(s):  
Residual Strength ◽  
Structural Damage ◽  
Damage Index ◽  
Sampling Technique ◽  
Damage Scenario ◽  
Strength Performance ◽  
Damage Scenarios ◽  
Longitudinal Strength ◽  
Oil Tankers ◽  
Double Hull

The primary aim of the present study is to propose an innovative method for assessing the safety of ships which have suffered accidental or in-service damages. Only a small number of probable scenarios for accidental or in-service damage representing all possible damage scenarios are selected using a sampling technique in which the random variables affecting the damage are probabilistically characterized. A damage index for the corresponding damage scenario is defined as a function of damage characteristics such as location and extent of the damage. The residual strength performance of a ship with the corresponding damage scenario can then be calculated by analytical or numerical methods. Once this process has been carried out for each of the damage scenarios selected, a diagram relating the residual strength performance to the damage index (abbreviated as the R-D diagram) can be established. This diagram will be very useful for a first-cut assessment of a ship’s safety immediately after it has suffered structural damage. The diagram can also be used to determine acceptance criteria for a ship’s safety against accidental or in-service damage. An applied example is shown to demonstrate the applicability of the proposed method in terms of developing a diagram between the ultimate longitudinal strength versus grounding damage index for four types of double-hull oil tankers – VLCC, Suezmax, Aframax, and Panamax.

A NEW METHOD FOR ASSESSING THE SAFETY OF SHIPS DAMAGED BY GROUNDING

2021 ◽  
Vol 154 (A1) ◽  
Author(s):  
J.K. Paik ◽  
D.K. Kim ◽  
D.H Park ◽  
H.B. Kim ◽  
M.S. Kim
Keyword(s):  
Residual Strength ◽  
Structural Damage ◽  
Damage Index ◽  
Sampling Technique ◽  
Damage Scenario ◽  
Strength Performance ◽  
Damage Scenarios ◽  
Longitudinal Strength ◽  
Oil Tankers ◽  
Double Hull

The primary aim of the present study is to propose an innovative method for assessing the safety of ships which have suffered accidental or in-service damages. Only a small number of probable scenarios for accidental or in-service damage representing all possible damage scenarios are selected using a sampling technique in which the random variables affecting the damage are probabilistically characterized. A damage index for the corresponding damage scenario is defined as a function of damage characteristics such as location and extent of the damage. The residual strength performance of a ship with the corresponding damage scenario can then be calculated by analytical or numerical methods. Once this process has been carried out for each of the damage scenarios selected, a diagram relating the residual strength performance to the damage index (abbreviated as the R-D diagram) can be established. This diagram will be very useful for a first-cut assessment of a ship’s safety immediately after it has suffered structural damage. The diagram can also be used to determine acceptance criteria for a ship’s safety against accidental or in-service damage. An applied example is shown to demonstrate the applicability of the proposed method in terms of developing a diagram between the ultimate longitudinal strength versus grounding damage index for four types of double-hull oil tankers – VLCC, Suezmax, Aframax, and Panamax.

Structural Damage Assessment Using Output-Only Measurement: Localization and Quantification

2013 ◽  
Author(s):  
Chin-Hsiung Loh ◽  
Min-Hsuan Tseng ◽  
Shu-Hsien Chao
Keyword(s):  
Damage Detection ◽  
Damage Assessment ◽  
Structural Damage ◽  
Damage Identification ◽  
Model Updating ◽  
Null Space ◽  
Singular Spectrum Analysis ◽  
Damage Index ◽  
Computation Efficiency ◽  
Output Only

One of the important issues to conduct the damage detection of a structure using vibration-based damage detection (VBDD) is not only to detect the damage but also to locate and quantify the damage. In this paper a systematic way of damage assessment, including identification of damage location and damage quantification, is proposed by using output-only measurement. Four level of damage identification algorithms are proposed. First, to identify the damage occurrence, null-space and subspace damage index are used. The eigenvalue difference ratio is also discussed for detecting the damage. Second, to locate the damage, the change of mode shape slope ratio and the prediction error from response using singular spectrum analysis are used. Finally, to quantify the damage the RSSI-COV algorithm is used to identify the change of dynamic characteristics together with the model updating technique, the loss of stiffness can be identified. Experimental data collected from the bridge foundation scouring in hydraulic lab was used to demonstrate the applicability of the proposed methods. The computation efficiency of each method is also discussed so as to accommodate the online damage detection.

FEM Free Damage Detection of Beam Structures Using the Deflections Estimated by Modal Flexibility Matrix

2021 ◽  
pp. 2150128
Author(s):  
Wen-Yu He ◽  
Wei-Xin Ren ◽  
Lei Cao ◽  
Quan Wang
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Damage Index ◽  
Element Model ◽  
Mode Shapes ◽  
Beam Structures ◽  
Flexibility Matrix ◽  
Damage Quantification ◽  
Modal Flexibility ◽  
The Cost

The deflection of the beam estimated from modal flexibility matrix (MFM) indirectly is used in structural damage detection due to the fact that deflection is less sensitive to experimental noise than the element in MFM. However, the requirement for mass-normalized mode shapes (MMSs) with a high spatial resolution and the difficulty in damage quantification restricts the practicability of MFM-based deflection damage detection. A damage detection method using the deflections estimated from MFM is proposed for beam structures. The MMSs of beams are identified by using a parked vehicle. The MFM is then formulated to estimate the positive-bending-inspection-load (PBIL) caused deflection. The change of deflection curvature (CDC) is defined as a damage index to localize damage. The relationship between the damage severity and the deflection curvatures is further investigated and a damage quantification approach is proposed accordingly. Numerical and experimental examples indicated that the presented approach can detect damages with adequate accuracy at the cost of limited number of sensors. No finite element model (FEM) is required during the whole detection process.

Scaled Acoustics Experiments and Vibration Prediction Based Structural Health Monitoring

2008 ◽  
Author(s):  
Nesrin Sarigul-Klijn ◽  
Israel Lopez ◽  
Seung-Il Baek
Keyword(s):  
Health Monitoring ◽  
Dimensional Reduction ◽  
Structural Damage ◽  
Numerical Study ◽  
Damage Index ◽  
Time Frequency ◽  
Structural Health ◽  
Reduction Techniques ◽  
Vibration Prediction ◽  
Dimensional Reduction Techniques

Vibration and acoustic-based health monitoring techniques are presented to monitor structural health under dynamic environment. In order to extract damage sensitive features, linear and nonlinear dimensional reduction techniques are applied and compared. First, a vibration numerical study based on the damage index method is used to provide both location and severity of impact damage. Next, controlled scaled experimental measurements are taken to investigate the aeroacoustic properties of sub-scale wings under known damage conditions. The aeroacoustic nature of the flow field in and around generic aircraft wing damage is determined to characterize the physical mechanism of noise generated by the damage and its applicability to battle damage detection. Simulated battle damage is investigated using a baseline, and two damage models introduced; namely, (1) an undamaged wing as baseline, (2) chordwise-spanwise-partial-penetration (SCPP), and (3) spanwise-chordwise-full-penetration (SCFP). Dimensional reduction techniques are employed to extract time-frequency domain features, which can be used to detect the presence of structural damage. Results are given to illustrate effectiveness of this approach.

Non-model-based damage identification of plates using measured mode shapes

2016 ◽  
Vol 16 (1) ◽  
pp. 3-23 ◽  
Author(s):  
Yongfeng Xu ◽  
Weidong Zhu
Keyword(s):  
Structural Damage ◽  
Damage Identification ◽  
Damage Index ◽  
Thickness Reduction ◽  
Aluminum Plate ◽  
Mode Shapes ◽  
Identification Method ◽  
Model Based

Mode shapes (MSs) have been extensively used to detect structural damage. This paper presents a new non-model-based damage identification method that uses measured MSs to identify damage in plates. A MS damage index (MSDI) is proposed to identify damage near regions with consistently high values of MSDIs associated with MSs of different modes. A MS of a pseudo-undamaged plate can be constructed for damage identification using a polynomial of a properly determined order that fits the corresponding MS of a damaged plate, if the associated undamaged plate is geometrically smooth and made of materials that have no stiffness and mass discontinuities. It is shown that comparing a MS of a damaged plate with that of a pseudo-undamaged plate is better for damage identification than with that of an undamaged plate. Effectiveness and robustness of the proposed method for identifying damage of different positions and areas are numerically investigated using different MSs; effects of crucial factors that determine effectiveness of the proposed method are also numerically investigated. Damage in the form of a machined thickness reduction area was introduced to an aluminum plate; it was successfully identified by the proposed method using measured MSs of the damaged plate.

scholarly journals Seismic Damage Model of Bridge Piers Subjected to Biaxial Loading Considering the Impact of Energy Dissipation

2019 ◽  
Vol 9 (7) ◽  
pp. 1481 ◽  
Author(s):  
Shangshun Lin ◽  
Zhanghua Xia ◽  
Jian Xia
Keyword(s):  
Energy Dissipation ◽  
Structural Damage ◽  
Biaxial Loading ◽  
Mechanical Performance ◽  
Damage Model ◽  
Damage Index ◽  
Seismic Damage ◽  
Bridge Piers ◽  
Dissipated Energy ◽  
The Impact

The large degradation of the mechanical performance of hollow reinforced concrete (RC) bridge piers subjected to multi-dimensional earthquakes has not been thoroughly assessed. This paper aims to improve the existing seismic damage model to assess the seismic properties of tall, hollow RC piers subjected to pseudo-static, biaxial loading. Cyclic bilateral loading tests on fourteen 1/14-scale pier specimens with different slenderness ratios, axial load ratios, and transverse reinforcement ratios were carried out to investigate the damage propagation and the cumulative dissipated energy with displacement loads. By considering the influence of energy dissipation on structural damage, a new damage model (M-Usami model) was developed to assess the damage characteristics of hollow RC piers. The results present four consecutive damage stages during the loading process: (a) cracking on concrete surface, (b) yielding of longitudinal reinforcements; (c) spalling of concrete, and (d) collapsing of pier after the concrete crushed and the longitudinal bars ruptured due to the flexural failure. The damage level caused by the seismic waves can be reduced by designing specimens with a good seismic energy dissipation capacity. The theoretical damage index values calculated by the M-Usami model agreed well with the experimental observations. The developed M-Usami model can provide insights into the approaches to assessing the seismic damage of hollow RC piers subjected to bilateral seismic excitations.

Intelligent Systems for Structural Damage Assessment

2018 ◽  
Vol 29 (1) ◽  
pp. 378-392
Author(s):  
Eleni Vrochidou ◽  
Petros-Fotios Alvanitopoulos ◽  
Ioannis Andreadis ◽  
Anaxagoras Elenas
Keyword(s):  
Damage Assessment ◽  
Intelligent Systems ◽  
Structural Damage ◽  
Fuzzy Inference ◽  
Damage Index ◽  
Reinforced Concrete Structure ◽  
Ann Model ◽  
Inference System ◽  
Time Frequency ◽  
Artificial Neural Network Ann

Abstract This research provides a comparative study of intelligent systems in structural damage assessment after the occurrence of an earthquake. Seismic response data of a reinforced concrete structure subjected to 100 different levels of seismic excitation are utilized to study the structural damage pattern described by a well-known damage index, the maximum inter-story drift ratio (MISDR). Through a time-frequency analysis of the accelerograms, a set of seismic features is extracted. The aim of this study is to analyze the performance of three different techniques for the set of the proposed seismic features: an artificial neural network (ANN), a Mamdani-type fuzzy inference system (FIS), and a Sugeno-type FIS. The performance of the models is evaluated in terms of the mean square error (MSE) between the actual calculated and estimated MISDR values derived from the proposed models. All models provide small MSE values. Yet, the ANN model reveals a slightly better performance.

Comparison of macroseismic-intensity scales by considering empirical observations of structural seismic damage

2020 ◽  
pp. 875529302094417
Author(s):  
Siqi Li ◽  
Yongsheng Chen ◽  
Tianlai Yu
Keyword(s):  
Structural Damage ◽  
Damage Index ◽  
Seismic Damage ◽  
Seismic Intensity ◽  
Calculation Model ◽  
Macroseismic Intensity ◽  
Intensity Scale ◽  
Failure Characteristics ◽  
Damage Survey ◽  
Seismic Engineering

In practice, seismic intensity is evaluated in accordance with a macroseismic-intensity scale recognized in the field of seismic engineering globally. The application of different seismic-intensity scales to evaluate the seismic damage of a specific structure due to an earthquake yields diverse results. On this basis, this study compared a few extensively used macroseismic-intensity scales. The results can be used as a reference to develop an international intensity scale. According to empirical structural-damage survey data from the Wenchuan earthquake (Mw = 8.0) that occurred on 12 May 2008 in China, the European Macroseismic Scale (EMS)-98, Medvedev, Sponheuer, and Karnik (MSK)-81, and Chinese Seismic Intensity Scale (CSIS)-08 intensity scales were utilized to evaluate the resulting damage. This study carried out a vulnerability analysis of typical structures, established vulnerability seismic-damage matrices, and mapped out vulnerability curves under different intensities. Our objective is to demonstrate that the use of multiple intensity scales can lead to very different intensity levels. The differences in the damage of typical structures under different intensity levels were obtained from an evaluation using the three aforementioned intensity scales. As a result, a calculation model of the mean damage index is proposed herein. Ultimately, this article conducted an analysis on the failure characteristics of typical structures in an earthquake and provided effective measures to improve seismic performance for future reference.

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