Soutenance de thèse Omar HASSOON

Quand :
28 juin 2017 @ 9 h 30 min
Où :
Ensta bretagne amphi 1

Omar hassoon 


Sous le sceau de l’Université Européenne de Bretagne

Ecole Doctorale des Sciences de la Mer – [ED156]

Doctorant à l’IRDL

Pôle Thématique de Recherche :

soutiendra une thèse de doctorat intitulée :

« Conception et optimisation des matériaux et
structures composites pour des applications navales « 

Design and Optimisation the Composite Material structures for Naval Applications: Effects of slamming

The use of composite materials begin to normalize in the various sectors, however, these structures are very susceptible to degradation of their properties and consequently a catastrophic failure. The response of deformable composite laminate subjected to water-entry impact can caused a phenomenon called hydroelastic effect due to water-flexible laminate interaction. This phenomenon may be large enough to cause damage in the composite materials as the result of repeating the slamming impact. For these reasons, the flexibility and the damage failure modes in composite materials introduce additional complexity for predicting hydrodynamic loads when interactive with water. This considered a key challenge to use these materials in marine applications. The main contributions of this work are the experimental and numerical study of the dynamic behavior of composite panels and the quantification of the effect of the flexibility of these structures on the hydrodynamic loads and the resulting deformations. To study these effects, laminate composite and sandwich panels with two different rigidities and subjected to various impact velocities have been investigated experimentally using high speed shock machine with velocity control system. The dynamic resistance was analysed in terms of hydrodynamic loads, dynamic deformation and failure mechanisms for different impact velocities. The general analysis of experiment results were indicated that more flexible panel has a higher peak force as velocity increases compared with higher stiffness panels. On the other hand, the slamming model was implemented in Abaqus/Explicit software based on Coupled Eulerian Lagrangian model approach (CEL). In addition, different damage modes are developed and constructed using a user-defined material subroutine VUMAT and implemented in Finite element method, including the intralaminar damage, debonding in skin/core interface, and core shear to cover all possible damage modes throughout structures. The numerical model gave a good agreement results in judging with experimental data for prediction of the hydrodynamic force and panel deformation. Additionally, this study gives qualitative and quantitative data which provides clear guidance in design phase and the evolution of performances during lifetime of composite structures, for marine structure designers.


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