scholarly journals Finite Element Analysis of the Effect of Currents on the Dynamics of a Moored Flexible Cylindrical Net Cage

2021 ◽  
Vol 9 (2) ◽  
pp. 159
Author(s):  
Zhongchi Liu ◽  
Sarat Chandra Mohapatra ◽  
C. Guedes Soares

A numerical model associated with wave–current interactions with a moored flexible cylindrical cage was developed based on the finite element method. An analytical model was formulated under the linearised wave theory and small structural response, and a semi-analytical solution was obtained using the Fourier Bessel series solution and least squares approximation method, along with a matching technique. The numerical results from the finite element analysis of the horizontal displacements for different design parameters under a uniform current were compared with the analytical model solutions. It was seen that they had a good level of agreement with their results. The effects of different current speeds and time on the cage shapes were analysed from the finite element results. Further, the mooring forces on the flexible cage for different values of the cage height and cage radius were also presented. The comparison of the results indicated that the numerical model results could be used with confidence in the design of a flexible cylindrical net cage for applications to offshore aquacultures.

Author(s):  
Mosfequr Rahman ◽  
Saheem Absar ◽  
F. N. U. Aktaruzzaman ◽  
Abdur Rahman ◽  
N. M. Awlad Hossain

In this work, the effect of ply stacking sequence on the structural response of multi-ply unidirectional fiber-reinforced composite laminates was evaluated using finite element analysis. The objective of this study was to develop a computational model to analyze the stress response of individual plies in a composite laminate for a given stacking sequence. A laminated composite plate structure under tensile loading was modeled in ANSYS. Stress profiles of the individual plies were obtained for each lamina. An Epoxy matrix with both unidirectional Graphite and Kevlar fibers was considered for the model. Three dimensional sectioned shell elements (SHELL181) were used for meshing the model. Several sets of stacking sequences were implemented, symmetrical to the mid-plane of the laminate. Symmetric stacking configurations of 6 layers stacked in ply angles of [0/45/-45]s, [0/60/-60]s, [0/45/90]s, and an 8-layered arrangement of [0/45/60/90]s were modeled for the analysis. The layer thickness was maintained at 0.1 mm. The results were compared against an analytical model based on the generalized Hooke’s law for orthotropic materials and classical laminate theory. A numerical formulation of the analytical model was implemented in MATLAB to evaluate the constitutive equations for each lamina. The stress distributions obtained using finite element analysis have shown good agreement with the analytical models in some of the cases.


Author(s):  
Venkata M. K. Akula

Analysis of pipelines subjected to corrosion is critical to ensure their integrity and safe operation. Although regulatory codes such as ASME, API, etc. can provide guidance in determining the fitness of a pipeline, often finite element analysis is needed to more accurately predict the structural response. In this paper, we present the techniques that could be used for performing buckling analysis of a pipe with a surface flaw. Several procedures, available in Abaqus, such as the nonlinear Newton-Raphson solver, the implicit dynamics solver, etc. are discussed in the context of predicting the collapse load. The assumptions associated with the use of each solver are presented along with a discussion on their predictive capabilities. Thereafter, parametric sensitivity analysis to study the influence of the design parameters on the collapse load is discussed. The sensitivity analysis requires automating the entire simulation workflow, including the flaw geometry, for predicting the collapse load.


Author(s):  
R. N. Margasahayam ◽  
H. S. Faust

Abstract A finite-element stress analysis of a one-piece, integrated, all-composite shaft and coupling is presented. In addition to a brief discussion of design-driving parameters, some limitations of the analytical techniques used for design development are described. The 3D finite-element method (FEM) was then used to evaluate critical stresses and strains experienced by the shaft coupling. A comparison of the results from the finite-element analysis and those from static bending, axial, and torsional tests conducted on these prototype shafts yielded excellent correlation. Some important considerations in the development of the FE model and the correlation of results with tests, especially in the design of composite materials, are addressed.


2013 ◽  
Vol 313-314 ◽  
pp. 1038-1041
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Chao Li

According to uncertainty of the design parameters for large span truss of installing wave-maker, in order to avoid the waste of materials,the truss is analyzed based on the finite element analysis software ANSYS to find out its weaknesses and various parts of the deformation. On the premise of ensuring the intensity and stiffness, the weight of the truss is reduced by adjusting its sizes and selecting different profiles, so as to achieve the optimization of the truss of installing wave-maker.


1986 ◽  
Vol 30 (4) ◽  
pp. 920-928
Author(s):  
Yoshinobu Maeda ◽  
Masafumi Mori ◽  
Sadami Tsutsumi ◽  
Toshihiro Chinzaka ◽  
Masataka Minoura ◽  
...  

1999 ◽  
Author(s):  
V. Madhavan ◽  
L. Olovsson ◽  
S. C. Swargam ◽  
R. Agarwal

Abstract We describe here the development and testing of a capability for finite element simulation of practical machining operations such as turning and milling, using 3D multi-material, explicit dynamic, Eulerian finite element analysis. In these simulations the workpiece material and the air surrounding it are modeled using Eulerian finite elements and the flow of the workpiece material into the air as a result of the action of the Lagrangian tool can be freely tracked. Tension tests and Taylor impact tests are simulated using the traditional Lagrangian approach as well as the Eulerian approach. Comparison of the results is used to understand the factors affecting the solution accuracy. Simulations of orthogonal machining using this technique show that the side flow of the chip is simulated realistically. Simulations of oblique machining with various rake and inclination angles confirm that the chip flow angle is independent of the rake angle. Inertial effects cause the chip flow angle to differ from the inclination angle as the weight of the chip increases. Simulations of turning and end milling show that chip formation and flow can be simulated ab-initio. The simulation capability described here can provide accurate results for various outputs of interest and is also computationally efficient, allowing a typical analysis to be completed within a day.


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