Use of localized necking and fracture as a failure criterion in ship collision analysis

2020 ◽  
Vol 73 ◽  
pp. 102787 ◽  
Author(s):  
Burak Can Cerik ◽  
Sung-Ju Park ◽  
Joonmo Choung
Author(s):  
Chien-Chang Chou

Navigational safety is an important issue in maritime transportation. The most frequent type of maritime accident in the port and coastal waters is the ship collision. Although some ship collision models have been developed in the past, few have taken account of wind and sea current effects. However, wind and sea current are critical factors in ship maneuvering. Therefore, based on the previous collision model without wind and sea current effects, this study further develops a ship collision model with wind and sea current effects. Finally, a comparison of the results for the proposed collision model in this study and the ship maneuvering simulator is shown to illustrate the effectiveness of the proposed mathematical model in this paper, followed by the conclusions and suggestions given to navigators, port managers, and governmental maritime departments to improve navigational safety in port and coastal waters.


2021 ◽  
Vol 288 ◽  
pp. 123050
Author(s):  
Bing Liu ◽  
Jingkai Zhou ◽  
Xiaoyan Wen ◽  
Jianhua Guo ◽  
Zhiheng Deng ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1099
Author(s):  
Qingqing Chen ◽  
Yuhang Zhang ◽  
Tingting Zhao ◽  
Zhiyong Wang ◽  
Zhihua Wang

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.


2021 ◽  
Vol 9 (5) ◽  
pp. 533
Author(s):  
Mirko Čorić ◽  
Sadko Mandžuka ◽  
Anita Gudelj ◽  
Zvonimir Lušić

Ship collisions are one of the most common types of maritime accidents. Assessing the frequency and probability of ship collisions is of great importance as it provides a cost-effective and practical way to mitigate risk. In this paper, we present a review of quantitative ship collision frequency estimation models for waterway risk assessment, accompanied by a classification of the models and a description of their main modelling characteristics. Models addressing the macroscopic perspective in the estimation of ship collision frequency on waterways are reviewed in this paper with a total of 29 models. We extend the existing classification methodology and group the collected models accordingly. Special attention is given to the criteria used to detect potential ship collision candidates, as well as to causation probability and the correlation of models with real ship collision statistics. Limitations of the existing models and future improvement possibilities are discussed. The paper can be used as a guide to understanding current achievements in this field.


2021 ◽  
Vol 28 (1) ◽  
pp. 139-152
Author(s):  
Teng Huang ◽  
Dongdong Zhang ◽  
Yaxin Huang ◽  
Chengfei Fan ◽  
Yuan Lin ◽  
...  

Abstract In this study, the flexural bearing capacity and failure mechanism of carbon fiber-reinforced aluminum laminate (CARALL) beams with a double-channel cross-section and a 3/2 laminated configuration were experimentally and numerically studied. Two types of specimens using different carbon fiber layup configurations ([0°/90°/0°]3 and [45°/0°/−45°]3) were fabricated using the pressure molding thermal curing forming process. The double-channel CARALL beams were subjected to static three-point bending tests to determine their failure behaviors in terms of ultimate bearing capacity and failure modes. Owing to the shortcomings of the two-dimensional Hashin failure criterion, the user-defined FORTRAN subroutine VUMAT suitable for the ABAQUS/Explicit solver and an analysis algorithm were established to obtain a progressive damage prediction of the CFRP layer using the three-dimensional Hashin failure criterion. Various failure behaviors and mechanisms of the CARALL beams were numerically analyzed. The results indicated that the numerical simulation was consistent with the experimental results for the ultimate bearing capacity and final failure modes, and the failure process of the double-channel CARALL beams could be revealed. The ultimate failure modes of both types of double-channel CARALL beams were local buckling deformation at the intersection of the upper flange and web near the concentrated loading position, which was mainly caused by the delamination failure among different unidirectional plates, tension and compression failure of the matrix, and shear failure of the fiber layers. The ability of each fiber layer to resist damage decreased in the order of 90° fiber layer > 0° fiber layer > 45° fiber layer. Thus, it is suggested that 90°, 0°, and 45° fiber layers should be stacked for double-channel CARALL beams.


2021 ◽  
Vol 9 (4) ◽  
pp. 410
Author(s):  
Fan Zhang ◽  
Xin Peng ◽  
Liang Huang ◽  
Man Zhu ◽  
Yuanqiao Wen ◽  
...  

In this study, a method for dynamically establishing ship domain in inland waters is proposed to help make decisions about ship collision avoidance. The surrounding waters of the target ship are divided to grids and then calculating the grid densities of ships in each moment to determine the shape and size of ship domain of different types of ships. At last, based on the spatiotemporal statistical method, the characteristics of ship domains of different types of ship in different navigational environments were analyzed. The proposed method is applied to establish ship domains of different types of ship in Wuhan section of the Yangtze River in January, February, July, and August in 2014. The results show that the size of ship domain increases as the ship size increases in each month. The domain size is significantly influenced by the water level, and the ship domain size in dry seasons is larger than in the wet seasons of inland waters.


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