scholarly journals Structural Analysis of an Aluminum Multihull

2015 ◽  
Vol 8 (17) ◽  
pp. 87
Author(s):  
David Fuentes ◽  
Marcos Salas ◽  
Gonzalo Tampier ◽  
Claudio Troncoso

Structural analysis of a multihull is relatively complex since the connecting structure introduces additional stress than those typical of a monohull. The aluminum trimaran presented in this work was designed within the framework of the research project “Conceptual Design of a High-performance Vessel for Passenger Transport in Chile’s Austral Zone”. The trimaran was structurally measured using the regulations of classification societies Germanischer Lloyd, Det Norske Veritas y LloydÅLs Register. For the scantlings obtained with each regulation a Finite Element Model was created and the structural analysis for the slamming and splitting moment events was made. The results were analyzed and the stress concentration zones were determined to compare them with admissible stresses and conclude whether the structural sizing adequately and safely responds to the design stresses.

Author(s):  
Huilong Ren ◽  
Chunbo Zhen ◽  
Chenfeng Li ◽  
Guoqing Feng

As a new high performance shipform, the structural form of trimaran is special and the stress concentration of its cross-deck structure is serious. According to the Rules for Classification of Trimaran Ships developed by Lloyd’s Register, the global finite element model of a trimaran is built. Main factors such as Thickness of bulkhead and wet deck, transitional forms and strengthening forms, which affect the stresses at local details are compared and discussed. Then the best structural form of trimaran cross-deck is given. The result can offer the reference for the trimaran’s design and development.


1985 ◽  
Vol 52 (4) ◽  
pp. 801-805 ◽  
Author(s):  
P. R. Heyliger ◽  
J. N. Reddy

A quasi-three dimensional elasticity formulation and associated finite element model for the stress analysis of symmetric laminates with free-edge cap reinforcement are described. Numerical results are presented to show the effect of the reinforcement on the reduction of free-edge stresses. It is observed that the interlaminar normal stresses are reduced considerably more than the interlaminar shear stresses due to the free-edge reinforcement.


Author(s):  
O. E. C. Prizeman ◽  
V. Sarhosis ◽  
A. M. D’Alri ◽  
C. J. Whitman ◽  
G. Muratore

Caerphilly Castle (1268-70) is the first concentric castle in Britain and the second largest in the UK. The dramatic inclination of its ruinous south west tower has been noted since 1539. Comparing data from historical surveys and a terrestrial laser scan undertaken in 2015, this paper seeks to review evidence for the long-term stability of the tower. Digital documentation and archival research by architects is collated to provide data for structural analysis by engineers. A terrestrial laser scan was used to create a detailed three dimensional finite element model to enable structural analysis of the current shape of the tower made by tetrahedral elements. An automated strategy has been implemented for the transformation of the complex three dimensional point cloud into a three dimensional finite element model. Numerical analysis has been carried out aiming at understanding the main structural weaknesses of the tower in its present condition. Comparisons of four sets of data: 1539, 1830, 1870 and 2015 enabled us to determine change albeit between very different methods of measurement.


2018 ◽  
Vol 42 (5) ◽  
pp. 467-482 ◽  
Author(s):  
Damien Caous ◽  
Nicolas Lavauzelle ◽  
Julien Valette ◽  
Jean-Christophe Wahl

It is common to dissociate load computation from structural analysis when carrying out a numerical assessment of a wind turbine blade. Loads are usually computed using a multiphysics and multibody beam finite element model of the whole turbine, whereas detailed structural analysis is managed using shell finite element models. This raises the issue of the application of the loads extracted from the beam finite element model at one node for each section and transposed into the shell finite element model. After presenting the methods found in the literature, a new method is proposed. This takes into account the physical consistency of loads: aerodynamic loads are applied as pressure on the blade surface, and inertial loads are applied as body loads. Corrections imposed by pressure and body load computation in order to match loads from the beam finite element model are proposed and a comparison with two other methods is discussed.


Author(s):  
Michaël Martinez ◽  
Sébastien Montalvo

Abstract The mooring of floating platforms is an important challenge for the offshore industry. It is an important part of the design engineering and, often, a critical point for the fatigue life assessment. A solution that could improve the fatigue life is to directly connect the mooring rope to the platform, without an intermediate chain. However this solution is not widespread and the behavior of a rope near such a connection is little known. The present paper proposes to better understand this behavior, thanks to a detailed finite element model of the rope. The study case is a steel wire rope directly connected to a floating wind turbine. A local finite element model of the rope has been built, where the wires are individually modeled with beam elements. One end of the rope is clamped, simulating the connection, while tension and cyclic bending oscillations are applied to the other end. A localized bending takes place near the connection, leading to stress concentration in the wires. The stress concentration and the local contact forces are calculated for each wire. These data are important entry parameters for a local failure or fatigue analysis. This latter is however not presented here. Despite IFPEN experience in the development of local finite element models of steel wire ropes, it is the first time that such a high capacity rope (MBL = 12 500 kN) is modeled. This is challenging because of the large diameter of the rope and the large number of wires. However this modeling approach is very valuable for such ropes, because the experimental tests are rare and very expensive.


2014 ◽  
Vol 912-914 ◽  
pp. 806-809
Author(s):  
Ming Feng Zheng ◽  
Yue Chen ◽  
Ya Lin Yan

Established a finite element model of the school bus based on the Hyper Mesh, take a finite element simulation about the various parts of the school bus parameters such as stress, displacement and deformation under 5 conditions. Through the analysis of the school bus to identify conditions displacement of stress more concentrated area as well as in operation, by optimizing improve the local structure of these regions,improve the stress concentration and safety.


Author(s):  
Bianca de Carvalho Pinheiro ◽  
Ilson Paranhos Pasqualino ◽  
Se´rgio Barros da Cunha

A nonlinear finite element model was developed to assess stress concentration factors induced by plain dents on steel pipelines subjected to cyclic internal pressure. The numerical model comprised small strain plasticity and large rotations. Six small-scale experimental tests were carried out to determine the strain behavior of steel pipe models during denting simulation followed by the application of cyclic internal pressure. The finite element model developed was validated through a correlation between numerical and experimental results. A parametric study was accomplished, with the aid of the numerical model, to evaluate stress concentration factors as function of the pipe and dent geometries. Finally, an analytical formulation to estimate stress concentration factors of dented pipelines under internal pressure was proposed. These stress concentration factors can be used in a high cycle fatigue evaluation through S-N curves.


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