Composites science and technology

Voids, the most studied type of manufacturing defects, form very often in processing of fiber-reinforced composites. Due to their considerable influence on physical and thermomechanical properties ...

https://journals.sagepub.com/doi/pdf/10.1177/0021998318772152

Voids in fiber-reinforced polymer composites: A review on their formation, characteristics, and effects on mechanical performance:

Reference EPFL-ARTICLE-184271doi:10.1016/j.compositesa.2012.08.001View record in Web of Science Record created on 2013-02-27, modified on 2017-05-10

Composites Part A: Applied Science and Manufacturing

This paper investigates comprehensive knowledge regarding joining CFRP and aluminium alloys in available literature in terms of available methods, bonding processing and mechanism and properties. The methods employed comprise the use of adhesive, self-piercing rivet, bolt, clinching and welding to join only CFRP and aluminium alloys. The non-thermal joining methods received great attention though the welding process has high potential in joining these materials. Except adhesive bonding and welding, other joining methods require the penetration of metallic pins through joining parts and therefore, surface preparation is unimportant. No model is found to predict the properties of jointed structures, which makes it difficult to select one over another in applications. The choice of bonding methods depends primarily on the specific applications. The load-bearing mechanism of bolted joints is predominantly the friction that is the first stage resistance. Hybrid joints performance is enhanced by combining rivets, clinch or bolts with adhesives.

/pdf/joining-of-carbon-fibre-reinforced-polymer-cfrp-composites-b1dn74dni2.pdf

Joining of carbon fibre reinforced polymer (CFRP) composites and aluminium alloys-A review

Bistable plates for morphing structures: A refined analytical approach with high-order polynomials

By the benefit of functional integration the advantages of fiber reinforced plastics (FRP) as construction material can be increased due to the possibilities of integrating sensors and actuators. In Regard to the layer-by-layer definition of the wall thickness, this class of material offers a high potential for the integration of additional smart elements within the stacking and forming process. In addition to the actual integration methods of sensors or actuators, the electrical signal transmission and contacting is of great importance for smart structures. Various approaches can be followed. On the one hand, the conductor path can be defined by means of a wire and, on the other hand, the definition of conductor paths can be accomplished by functionalized films (by means of printing technology). Within this paper, experimental investigations are intended to demonstrate the suitability of screen-printed conductor paths for the press-technical transformation of FRP structures. In addition to the variation of the screen printing material and the film material, for a material-homogeneous integration, an evaluation of a corresponding selection of materials takes place with respect to the stresses derived from the deformation-technical boundary conditions.

Experimental Investigations on Integrated Conductor Paths in Fiber-Reinforced Thermoplastic Composite Structures

Gegenstand der vorliegenden Erfindung ist ein Verfahren zur kontinuierlichen Herstellung von Faserverbundhalbzeug und ein derart hergestelltes Faserverbundhalbzeug. Das im Verfahren eingesetzte Matrixmaterial weist einen Abstand zwischen Erweichungstemperatur und Vernetzungstemperatur auf. Im unvernetzten Zustand verfugt es uber thermoplastische und im vernetzten Zustand uber duroplastische Eigenschaften. Das Verfahren sieht das Aufbringen von Verstarkungsfasermaterial und unvernetztem Matrixmaterial auf ein Transportband und das Pressen von Verstarkungsfasermaterial und unvernetztem Matrixmaterial zu dem Faserverbundhalbzeug vor. Kennzeichnend ist, dass das Matrixmaterial wahrend des Pressens aufgrund einer Erwarmung in erweichtem Zustand vorliegt, jedoch dabei nicht vernetzt. Das erfindungsgemase Faserverbundhalbzeug bestehet aus Verstarkungsfasermaterial und mit diesem verpressten, unvernetztem Matrixmaterial, wobei das Matrixmaterial ein Einkomponenten-System ist, das einen deutlichen Abstand zwischen Erweichungstemperatur und Vernetzungstemperatur aufweist und das in diesem Temperaturbereich thermoplastisch umgeformt werden kann.

Maik Gude

Papers

Experimental Investigations on Integrated Conductor Paths in Fiber-Reinforced Thermoplastic Composite Structures

Faser-Kunststoff-Verbundhalbzeug und Verfahren zur Herstellung