If a composite material can be defined as a combination of two or more distinct materials to attain new properties that can not be achieved by those of individual components acting alone, then it is only natural that production errors and material flaws will occur, as in every other manufacturing process. These composite material flaws can have a butterfly effect on the whole structure, which not only can bring tragic outcomes in the safety-critical applications but can also damage the economic health of the composite manufacturer and subsequently assembly companies.
To list the examples – common types of damages occurring in carbon composites include debonding, delamination, matrix failure, crazing, broken fibers. Manufacturing of anomaly detection methods are often inherent in composites, naturally, the introduction of composites into large scale production directly depends on the successful application of non-destructive testing (NDT).
Even though some of the current NDT methods are better in certain environments than the others, so far there isn’t introduced any ‘golden means’ technology, whether using the coin tapping, vibration analysis, thermography, optical, ultrasound, radiography methods or eddy current testing various limitations exist including limited accuracy, limited penetration depth, composite surface accessibility, methods being cost-intensive or time-consuming, limited use in a dusty industrial environment, need of a vibration-free environment or being unable to determine damage severity, etc. In general only a few of them allow for real-time measurements.
For any sector professional, it’s no secret that we are living in a world where many composite-based structures are serving beyond the lifetime they were designed for and they are likely to remain in service for even longer. Many composite structures are in need of immediate attention. Their repair, maintenance, or replacement will cost millions of dollars, however, it still needs to take place.
One company, RVmagnetics, believe that the composite industry needs to take a new road and develop smart self-monitored composites that can provide significant added value on top of the traditional NDT methods. How to achieve this?
RVmagnetics has developed MicroWires, miniaturized, magnetic, contactless microsensors of physical quantities (sensing temperature, pressure, and magnetic field directly and pull, axial stress, mechanical stress, torsion, bending, vibration, etc. indirectly).
The MicroWires are composite materials themselves, they consist of metallic nucleus and glass coating. MicroWire is a passive, unpowered element. To ‘power’ it, enabling sensing and real-time live data, a set of coils (powered, active element) and electronics are placed within the range of 10cm and allow contactless sensing. Without causing any material flows, or adding almost no additional weight MicroWires can be easily introduced into composites such as carbon fiber composites, glass fiber, ceramic composites and plastic composites.
The MicroWires are simply be embedded between composite layers in the production process which, naturally gives you control over:
- Each part of the production process (e.g. measure temperature locally not only on the surface but also in between the layers)
- Random inspections and defect detections
- Real-time live data about the current state of the composite (up to ten thousand times per second resolution) through the lifetime the composite is used
The RVmagnetics solution provides a real opportunity to create self-monitored composites that reduce the likelihood of material failure, optimizes the production process to manage composite properties minimizing material and production costs, accelerating processes (composite decking, bonding, etc.) without risking cracks or other failures. In a nutshell – increasing quality level while decreasing material waste.
Combining AI with live data brings the opportunity to increase safety drastically, provide data on remaining useful life (RUL) for the structure. The financial gain lays in reducing the frequency of maintenance tasks, transforming the preventive and reactive maintenance into predictive maintenance allowing a maintenance timetable to be created ‘on the go’.
While current structural health monitoring methods are valuable in detecting and preventing potential damages in the production process or post-production RVMagnetics strive for safety, real-time measurements and industry transformation towards digital. MicroWire sensing technology provides a gateway to real-time data from places that have been impossible to access thus far.
For more information: www.rvmagnetics.com