A New Approach to Compute the Non-Linear Whipping Response Using Hydro-Elastoplastic Coupling

Author(s):  
George Jagite ◽  
Hervé le Sourne ◽  
Patrice Cartraud ◽  
Šime Malenica ◽  
Fabien Bigot ◽  
...  

Abstract In the last ten years, the importance of whipping on the extreme hull girder loads has received much attention, but its consequence on the hull girder’s collapse is still unclear. The most common practice is to consider the structural behavior as linear-elastic in the hydro-elastic coupling, and as non-linear elasto-plastic in the ultimate strength evaluation. In order to investigate the influence of the non-linear structural behavior on the hydro-structure interaction responses, a new hydro-elastoplastic model is proposed to compute the non-linear whipping response. The structural part is modeled as two beams connected by a non-linear hinge, which follows the collapse behavior of a ship’s hull girder. The hydrodynamic problem is solved using the three-dimensional boundary element method, and the exact coupling between the structural model and the hydrodynamic one is made by making use of the shape function approach. Finally, the fully-coupled hydro-elastoplastic problem is solved directly in time-domain by numerical integration.

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
Osama Mohamed ◽  
Rania Khattab

This paper evaluates the practice of using moment connections in the perimeter of the structural system and shear connections within the interior connections of the three-dimensional structural system from the perspective of resistance to progressive collapse. The enhanced resistance to progressive collapse associated with using moment resisting connections at the perimeter as well as internal to the three-dimensional system is assessed. Progressive collapse occurrence and system resistance are determined using the alternate path method which presumes a primary load carrying-member is notionally removed. The paper compares the structural response determined using linear elastic, non-linear elastic and non-linear dynamic analyses. Linear and non-linear static analyses are found to be incapable of capturing the response pursuant to the loss of the primary load carrying member. The analysis procedures used in this study followed (for the most part) the United States Department of Defense Guide for Progressive Collapse Resistant Design of Structures.


1994 ◽  
Vol 29 (2) ◽  
pp. 137-145 ◽  
Author(s):  
M Y Tsai ◽  
J Morton

The three-dimensional nature of the state of deformation in a single-lap test specimen is investigated in a linear elastic finite element analysis in which the boundary conditions account for the geometrically non-linear effects. The validity of the model is demonstrated by comparing the resulting displacement fields with those obtained from a moiré inteferometry experiment. The three-dimensional adherend and adhesive stress distributions are calculated and compared with those from a two-dimensional non-linear numerical analysis, Goland and Reissner's solution, and experimental measurements. The nature of the three-dimensional mechanics is described and discussed in detail. It is shown that three-dimensional regions exists in the specimen, where the adherend and adhesive stress distributions in the overlap near (and especially on) the free surface are quite different from those occurring in the interior. It is also shown that the adhesive peel stress is extremely sensitive to this three-dimensional effect, but the adhesive shear is not. It is also observed that the maximum value of the peel stress occurs at the end of the overlap in the central two-dimensional core region, rather than at the corners where the three-dimensional effects are found. The extent of three-dimensional regions is also quantified.


Author(s):  
Wonhyuk Koh ◽  
Sungwoo Kang ◽  
Myunghwan Cho ◽  
Jung Yul Yoo

Three-dimensional fluid-structure interaction problem arising from steady flow in non-linear elastic tube is studied numerically by using a finite element software, ADINA. Strain-energy density function is used for non-linear elastic analysis of solid material. Navier-Stokes equation coupled with elastic wall condition is solved for the fluid flow. To simulate interactions between the fluid and the solid domains, arbitrary Lagrangian-Eulerian (ALE) formulation is utilized. For validation, thin-walled linear elastic collapsible tubes is computed and compared with previous numerical results. The tube collapses into the buckling mode N = 2 and the results are in excellent agreement with a previous study. Then, the results for linear elastic tube are compared with those for non-linear elastic tube to show the effects of non-linear elasticity of the wall. The wall material is considered to be non-linear hyperelastic and isotropic. The non-linear elastic wall shows the tendency to preserve its shape more than the linear material. The deformation patterns, pressure distributions of the tube with non-linear elastic material are significantly different from those with linear elastic material.


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