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

Optimisation of composite shapes with the help of genetic algorithms

A freely vibrating test stand for experiments with carbon fibre reinforced (CFRP) cross-ply specimens loaded in pure bending, is presented and used for fatigue testing. The developed test stand does not generate out-of-plane shear forces within the specimens, thus minimises specimen heating and enables testing at high frequencies above 100 Hz.

Characterisation and modelling of the inter-fibre cracking behaviour of CFRP up to very high cycles

With a novel Freeze Foaming method, it is possible to manufacture porous cellular components whose structure and composition also enables them for application as artificial bones, among others. To tune the foam properties to our needs, we have to understand the principles of the foaming process and how the relevant process parameters and the foam's structure are linked. Using in situ analysis methods, like X-ray microcomputed tomography (µCT), the foam structure and its development can be observed and correlated to its properties. For this purpose, a device was designed at the Institute of Lightweight Engineering and Polymer Technology (ILK). Due to varying suspension temperature and the rate of pressure decrease it was possible to analyze the foam's developmental stages for the first time. After successfully identifying the mechanism of foam creation and cell structure formation, process routes for tailored foams can be developed in future.

Investigation of the Foam Development Stages by Non-Destructive Testing Technology Using the Freeze Foaming Process.

A vibratable diaphragm (1) having passive tightened single layers of isotropic or anisotropic layers with active function elements (4) formed as a multilayer bond, is held in a holder (2). The diaphragm accepts deformation energy for different stable equilibrium positions, the change in which causes sound.

Wide frequency range sound generation system for internal noise reduction measure in motor vehicle, has vibratable diaphragm made of several passive tightened layers and active function elements

Maik Gude

Papers

Optimisation of composite shapes with the help of genetic algorithms

Characterisation and modelling of the inter-fibre cracking behaviour of CFRP up to very high cycles

Investigation of the Foam Development Stages by Non-Destructive Testing Technology Using the Freeze Foaming Process.

Wide frequency range sound generation system for internal noise reduction measure in motor vehicle, has vibratable diaphragm made of several passive tightened layers and active function elements

Effect of saw-tooth ply drops on the mechanical performance of tapered composite laminates