Polymer matrix composites are currently used in many structural applications that require a significant reduction in weight for energy and/or environmental reasons. A paradigmatic example is the new composites developed for aeronautical applications.
For example, as much as 25% of the weight of the new AIRBUS A380 aircraft is made up of composites (GLARE® and fibreglass and carbon fibre composites) in its wings, fuselage and tail sections and the new Boeing 787 Dreamliner boasts the first fuselage made entirely of composites. However, for these structural designs to be truly efficient, these new materials must be exploited to their maximum potential.
Unless our knowledge of the materials progresses, this potential will be restricted by the presence of internal defects (delaminations, voids, wrinkles, etc.), which arise either from the manufacturing process or during the assembly and maintenance of these structures.
But, how can these internal defects be found? And once they have been located, what makes the difference between a defect being harmless and it genuinely compromising the structural integrity of the material? Currently, the aeronautical industry is required to carry out vast batteries of mechanical tests on different scales (from the material itself, through sub-components, to the entire structure), which can take as long as seven years, to validate and certify new materials for use. Wouldn't it be better to have the necessary understanding to be able to predict the mechanical behaviour of a new composite and, more importantly, the effect of any defects that could occur? Following several recent advances, this understanding is now within the reach of Materials Science and Engineering.On the one hand, non-destructive analysis techniques have been developed, such as X-ray computed tomography. This technique is based on computer-assisted reconstruction of the three-dimensional microstructure of the material based on X-ray radiographies taken from various viewing angles. The development of new X-ray generation and detection techniques means it is now possible to achieve sub-micrometer resolutions, making this technique a valuable tool for internal characterisation of defects and the study of propagation of damage in composites with great reliability, as can be seen in the following images.
On the other, new simulation strategies and the increase in computational power over recent years have made it possible to develop powerful micro- and meso-mechanical models. These explicitly take into account the configuration of fibres (and the typology of the defects), making it possible to predict both the mechanical behaviour and the mechanisms responsible for failure, as well as how they interact with pre-existing defects in the material.
In order to go into greater depth on these aspects and to develop tools that will enable composite manufacturers to distinguish between the various types of defects, IMDEA-Materiales is leading the DEFCOM project, with funding from the regional government of Madrid through the ERA-net MATERA network. The consortium, made up of Austrian universities and companies from aeronautical industry (SECAR) and the wind power sector, will spend three years working in this subject. For this, IMDEA-Materiales has a state-of-the-art X-ray nanotomography device, Phoenix Nanotom, with a nominal resolution of 0.3?m, and is using the most advanced multi-scale simulation techniques applied to composites.
IMDEA | alfa
3-D-printed structures shrink when heated
26.10.2016 | Massachusetts Institute of Technology
From ancient fossils to future cars
21.10.2016 | University of California - Riverside
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
26.10.2016 | Materials Sciences
26.10.2016 | Health and Medicine
26.10.2016 | Physics and Astronomy