Thermographic testing of CFRP structural components in motorsports

The use of carbon fiber reinforced plastics (CFRP) is indispensable in professional racing to push the performance limits of vehicles. Maximum weight savings while ensuring the desired functionality are the focus of design and product development. In addition to flow-optimized aerodynamic components, structural components such as complete chassis (monocoques), chassis parts and transmission and unit carriers are primarily made of CFRP. These are often hybrid components that utilize specific advantages of different materials to increase mechanical component properties.

The Application:

Non-destructive characterization using active thermography techniques plays an important role in the context of quality assurance measures for CFRP components. Due to their complex structure, CFRP hybrid components, such as monocoques, can have a wide range of material defects, such as delamination, air pockets (porosity) or impact damage. In racing, the metallic inserts embedded in the CFRP structure are of particular interest. Among other things, chassis components as well as transmission and unit carriers are assembled there. It is therefore of key importance that these have a strong, high-strength adhesive bond to the CFRP laminate. This is where active thermography comes into play, providing valuable information regarding the bonding of these inserts to the surrounding CFRP laminate.

The challenge:

In racing, not only complex component structures and high deadline pressure make quality assurance of CFRP structural components a challenge. Component damage is hardly or often not even visually detectable on the surface. Nevertheless, the structural integrity inside the component can be significantly impaired in this case.

The solution:

Active thermography techniques provide an efficient inspection method for characterizing CFRP structures. With these imaging methods, even large component areas can be inspected quickly, without contact and with depth resolution, whereby even complex shaped structures and sub-surface interfaces can be easily characterized within a few minutes. This is where our powerful OTvis/PTvis inspection systems with their intelligent excitation and evaluation technology come into play.

The procedure:

The newly manufactured component is first subjected to a zero test, i.e. before it is installed in the vehicle. In addition to quality assurance (ensuring structural integrity), the main focus here is on documenting the actual condition. After the component has been used, e.g. as part of approval processes or following accidents in the racing series, the components are subjected to a repeat test in exactly the same configuration. The comparison of the zero test with the current results thus enables a quick and reliable statement to be made about the change in condition of the component. Our experienced ISO9712-certified testers support manufacturers and users in their decision-making processes on how to handle the stressed components in the future.