RD1-TT flexes impressive educational credentials

Coventry University Ph.D. student ‘amazed’ at nonlinear resonance non-destructive testing capabilities for composite aerospace parts.

Having established in 2007 as a spin-out from Exeter University, Education has been integral to the research and development of non-destructive testing solutions at Theta Technologies. Not willing to condemn their educational credentials to history, Theta Technologies is embracing opportunities to work with educational institutions and their students to support engineering and manufacturing developments, as well as refining products and service offering available to customers.

Last week, Theta Technologies was thrilled to welcome a Ph.D. student from Coventry University to their site at Exeter Science Park to perform a series of resonance non-destructive tests on composite components in an attempt to validate some key data as part of his project.

Evangelos (Vagelis) Symeon Apostolopoulos has spent months developing a digital twin model for a composite structure in conjunction with a number of key industry partners. A ‘digital twin’ is a digital model of a structure that transmits and receives data for a physical component. The part, destined for use in aerospace, will ultimately be used to make maintenance and operational decisions.

With a fundamental component of Vagelis’ project requiring structural health monitoring and damage detection, he knew he needed to source an effective testing solution to assess the integrity of the composite structures that he had developed. When a course supervisor highlighted the capabilities of Theta Technologies’s nonlinear resonance NDT technology to him, Vagelis wasted no time in getting in touch with the team to setup a visit.

Vagelis, who spent two days on site at Theta Technologies, was not only looking to detect the natural frequencies of a component to be used in space applications, but having previously utilised more conventional NDT methods, he also wanted to use the acquired data to help determine the most effective solution to identify damage in a component of this nature. Vagelis arrived with two composite samples that were to be assessed using Theta Technologies’s unique nonlinear resonance NDT method, and after a series of tests, there was a clear distinction between the results. The damage index data received for each component clearly indicated that one part was free of flaws and the other was defective.


I was given the opportunity to use the RD1-TT nonlinear resonance machine and was amazed by its capabilities, its speed and damage detection ability compared to more traditional NDT techniques.


When asked about his visit, Vagelis stated that “The team at Theta Technologies was very kind in showing me how to use the testing equipment and I was able to collect all the information I needed during the experiments. The data that I collected allowed me to gain an insight into the different non-destructive inspection techniques that can be deployed on this type of specimen. I was also given the opportunity to use the RD1-TT nonlinear resonance machine and was amazed by its capabilities, its speed, and damage detection ability compared to more traditional NDT techniques like ultrasound and thermography”.

Research and Development Manager at Theta Technologies, Daniel Sanmartin helped coordinate the visit and the testing process at the offices in Exeter and was pleased with the outcome. “Theta Technologies is thrilled to be providing guidance and support to Vagelis during the duration of his Ph.D. project in order to increase its commercial relevance. During his visit to our lab, he had access to our state-of-the-art NDT equipment and our first commercial product RD1-TT in order to make very high precision resonance measurements”.

Daniel went on to say, “Vagelis used RD1-TT in representative carbon fibre composite structures used in Aerospace in order to validate his Finite Element Analysis models assumptions with measured experimental values. Eventually, his aim is to create digital twins of these structures which would be a very valuable training tool to the NDT community”.

When asked to summarise the success of his visit, Vagelis stated, “Overall, my visit to Theta Technologies was not only successful, but also very enjoyable and I would love to visit again to have the opportunity to take full advantage of the RD1-TT. I was amazed by the capabilities of RD1-TT and I was also able to gain valuable testing experience which will greatly help me in the future as a researcher”.

Theta Technologies is continuing to work with customers to offer rapid, cost-effective non-destructive testing solutions for a variety of materials including conventional metals, composites and 3D-printed components. This latest work with Vagelis has further reaffirmed the capabilities of nonlinear resonance NDT to provide fast, accurate results data. Read more about the unique benefits of Theta’s technology by visiting their website at www.thetandt.com