Experimental study of the mechanical behaviour of pin reinforced foam core sandwich materials under shear load

Dimassi, M. Adli; Brauner, Christian; Herrmann, Axel S.

doi:10.1088/1757-899x/118/1/012012

Cited by 4 publications

(2 citation statements)

References 2 publications

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“…In order to make foam-based sandwiches more attractive, it seems useful to apply foam cores with a low density to lower the areal weight, while reinforcing the core to optimize the mechanical performance. The main idea is to strengthen the foam core in order to improve the compression and shear performance by means of inserting rods or pins [17][18][19]. While the inserted elements bear the majority of the loads, the surrounding foam prevents them from buckling and contributes in transferring shear loads.…”

Section: Introductionmentioning

confidence: 99%

Modified foam cores for full thermoplastic composite sandwich structures

Grünewald

Orth

Parlevliet

et al. 2017

Jnl of Sandwich Structures & Materials

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Full thermoplastic composite sandwich structures with a foam core offer the possibility to be manufactured by fusion bonding in significant shorter cycle times than thermoset-based sandwiches. However, the application of foam cores results in lower mechanical properties such as compression and shear strength compared to honeycomb cores, therefore foam-based sandwiches cannot compete with sandwich structures based on Aramid/phenolic honeycomb cores, the current state of the art. In order to improve the mechanical performance of foam core-based sandwiches while maintaining their advantages, concepts to reinforce the foams were developed in this study. By introducing rods either orthogonally or diagonally to the skin plane, which are fusion bonded to the skins during processing, the compression and shear properties can be improved by up to 1000% and 72%, respectively. Even when correcting for the weight increase, an improved specific compression strength could be achieved. And therefore, the pinning looks especially promising when only applied locally in highly loaded areas for example.

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Section: Introductionmentioning

confidence: 99%

Modified foam cores for full thermoplastic composite sandwich structures

Grünewald

Orth

Parlevliet

et al. 2017

Jnl of Sandwich Structures & Materials

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“…In order to overcome the issue of crack propagation owing to impact loading and to improve the fracture toughness of foam core sandwich, dry fibre bundles are inserted in the foam material under a specific inclination angel and pattern. The pins improve the stiffness and the strength of the foam core [4], stop the initiated cracks and maintain the integrity of the structure [5]. The studied pinreinforced specimens were pinned automatically using the tied foam core technology [6].…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Low Velocity Impact on Pin-Reinforced Foam Core Sandwich Panel

Dimassi

Herrmann²

2017

KEM

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The use of sandwich structures is well established in industrial sectors where high stiffness and strength combined with lightweight are required, like in marine, wind turbine and railway applications. However, the vulnerability of sandwich structures to low-velocity impacts limits its use in primary aircraft structures. Pin reinforcement of the foam core enhances the out-of-plane properties and the damage tolerance of the foam core. In this paper, a finite element model is proposed to predict the impact behaviour of pin-reinforced sandwich structure. An approach based on the building block approach was used to develop the model. Multi-scale modelling in the impact region that considers the delamination of the face sheet using cohesive zone elements was employed to increase the accuracy of the simulation. Impact tests were performed to validate the numerical model. A good agreement between numerical and experimental results in terms of contact-force displacement history and failure mode was found.

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