Thermal non-destructive testing can detect internal defects through target excitation and the observation of thermal differences on a target surface. At DES, Diagnostic Engineering Solutions, a spin-off company of Politecnico di Bari, Italy, NDT specialists use a wide variety of thermal imaging cameras from FLIR to characterize possible defects inside composite materials.
NDT is a widely used method to evaluate the properties of a material, component or system without causing damage. The method relies heavily on the use of thermal cameras and makes it possible to detect defects and points of failure in composites, solar cells, bridges, and electronics.
DES - SCIENTIFIC AND TECHNOLOGICAL PARTNER FOR STRUCTURAL DIAGNOSTICS OF PRODUCTS AND PROCESSES
The core business of DES is centered around the development of hardware and software systems for structural diagnosis, tailored to customer needs. As such, the company makes intensive use of thermal imaging technology of FLIR Systems for integration into larger inspection systems. Industries served by DES include aeronautics, mechatronics, the energy industry, naval systems, food and agriculture, the chemical and plastics industry, and many more.
The many application areas DES is active in result from the fact that almost any process in nature is related to a change in temperature. In other words, if you can monitor the change of temperature, you can monitor the process. Umberto Galietti, president of DES, comments: “Our main expertise is non-destructive testing and defect characterization in composite materials. We use thermal cameras from FLIR Systems very intensively, because they really give us added value for the analysis of composite materials. Thermal research cameras provide very high resolution, which makes it easy to characterize defects inside a material. The quality of the cameras, the quality of the service, and the variety of possible solutions that we have from FLIR is exactly what we needed for our solutions.”
Umberto Galietti: “The quality of the cameras, the quality of the service, and the variety of possible solutions that we have from FLIR is exactly what we needed for our solutions.”
COOLED AND UNCOOLED THERMAL CAMERAS
For many applications in research and development and process monitoring, DES makes use of cooled cameras, which have distinct advantages over uncooled cameras. They can see minute temperature differences, have better image quality, and can be used to capture high-speed thermal transients. Umberto Galietti: “FLIR is an excellent partner, because for our applications, we need a wide variety of thermal cameras with a wide variety of performance, from uncooled to cooled cameras. FLIR has a high-quality solution for any possible application.”
WELDES: NON-DESTRUCTIVE TESTING FOR WELDED JOINTS
One solution from DES that makes use of FLIR cameras is WELDES: an inspection system for thin welding by means of active thermography (laser and/or flash excitation). WELDES can be used to inspect welded joints for micro- or macro-defects. WELDES makes use of the company’s proprietary analysis software, IRTA - Infrared Testing and Analysis. The WELDES system allows researchers to see welding defects in the size of microns. The system can be fully automated; it can be put on an anthropomorphic robot - and on a working station to monitor any kind of components. WELDES makes use of cooled FLIR cameras, like the ultrasensitive FLIR X6540sc camera. “The FLIR X6540sc is exactly what we need, because this cooled camera offers us the frame rate we need, the thermal resolution we need and all possible connectivity and control features to perform this kind of quality non-destructive testing.”
WELDES is an inspection system for thin welding by means of active thermography (laser and/or flash excitation), which makes use of the FLIR X6540sc camera.
NON-DESTRUCTIVE TESTING OF COMPOSITE MATERIALS
NDT for composite materials is the core business of DES. The MULTIDES inspection system is the company’s flagship product, used for nondestructive testing of components and structures with active thermographic methods with multiple thermal exciters (flash and halogen lamps, ultrasounds, laser, microwaves). Umberto Galietti: “We heat up a component and we analyze the thermal transient. This way, we are able to spot whether there are defects and which kind of defects there are. Uncooled FLIR thermal cameras are so good that you can use them to perform analyses typically performed by cooled cameras, such as lock-in analysis. With our MULTIDES System, you can use a wide variety of cameras, but we prefer the FLIR A655sc, because it’s compact and it gives you everything you need to obtain excellent results. The FLIR A655sc is stable, it doesn’t have any thermal drift, and it offers excellent frame rate control and excellent thermal resolution.”
The MULTIDES inspection system is the company’s flagship product, used for non-destructive testing of components and structures with active thermography.
THERMOELASTIC STRESS ANALYSIS (TSA)
Stress and fatigue testing are common test methods in mechanical engineering and materials science, but provide limited information on complex structures. Thermal stress mapping provides thousands of stress measurements simultaneously, even on geometrically complex components. Compared to strain gauges, this technique provides faster, more complete information to researchers. Thermal cameras also allow DES NDT specialists to perform Thermoelastic Stress Analysis (TSA). This includes obtaining stress maps of mechanical components and analyzing the change of temperature in a component due to the change in load. In a matter of seconds, stress maps of mechanical components can be generated, so the mechanical design can be assessed. TSA is also very useful to validate a numerical model in a fast way.
A tie rod with a dynamic load simulates the in-service condition loading. The stress map of the tie rod shows the stress concentration which allows you to easily see the failing or breaking component.
The FLIR X6540sc is designed to provide the best thermal measurement performance together with the most advanced connectivity.