Renaldas Raišutis is a professor at KTU Faculty of Electrical and Electronics Engineering, Chief researcher and the Head of Numerical Simulation Laboratory at KTU Prof K. Baršauskas Ultrasound Research Institute.
Ponte Morandi bridge collapse in Genoa, Italy, in 2018, because of structure corrosion; Xinjia Express Hotel that was used as coronavirus quarantine centre collapsed this year in Quanzhou, China; Alexander L. Kielland oil platform accident in 1980, because of defective weld condition – these are just a few global disasters examples of the last few decades. They could have been prevented or at least significantly reduced if the internal structural defects were found on time, and people were warned that it was no longer safe to work there.
Many other disasters involving ships, planes, bridges, power plants, renewable energy sources – wind farms – various tank accidents have claimed many lives and billions of direct and indirect financial losses. They are becoming a “driving force” for secure strategic energy, transport, aviation industry operations.
Thus, there is a need to continuously develop, implement and improve specialised technological solutions for monitoring object conditions and structures in strategic industrial sectors.
Security is always important, especially during a pandemic
Specially trained personnel performs routine inspection procedures using non-destructive testing and diagnostic methods at specified intervals periodically. It can take between 1 and 10 years between the inspections. Therefore, there is a risk that a minor defect not detected during one inspection will become dangerous before the next one, which could lead to an accident.
Now that the global coronavirus (SARS-CoV-2) pandemic and global quarantine limits people’s mobility, technical personnel cannot carry out inspections. International flights are cancelled; the staff of various institutions is quarantined, and the access to the inspection facilities is impossible. That is why many objects remain unsupervised.
Scientific advances are already allowing to mitigate these risks through autonomous, continuous structure health monitoring (SHM) systems.
Such systems must ensure that engineering structures are operating safely and are reliable, taking into account their current condition and the remaining “safe” service life. During SHM research, the research objects are in operation, fully functional, and they prevent the object downtime incurring no financial losses.
The cost of 1-hour downtime for energy facilities can range from tens of thousands up to hundreds of thousands of euros and more. The daily downtime costs of an aircraft can range from tens of thousands up to one hundred thousand euros.
SHMs can be performed with fibre optic sensors, mechanical distortion sensors, acoustic emission sensors, vibration sensors, and ultrasonic wave excitation and reception sensors. The biggest advantage of using ultrasound in SHM systems is the high applicability without being limited by the scale, size or long-range of the ultrasonic waves.
Can be monitored remotely
Using SHM ultrasonic guided waves, it is possible to continuously monitor various infrastructures or their elements, such as electrical components, walls and joints of various pipelines, wind turbine blades, constructions of transport and aeronautical composites. The low frequency guided ultrasonic waves emanating from the structure respond to its inhomogeneity and emerging defects.
Data and signals collected by SHM systems and processed in the initial stage are transmitted via various communication channels and automatically processed in the next stage using specialised data and signal processing algorithms.
Using artificial intelligence algorithms and responding to Industry 4.0 needs, the operator of a particular object receives an automated advisory response: the structure or object is safe/ not safe for further operation.
Returning to the challenges posed by the pandemic, there is no need to send technical staff to the site for periodic inspections, and the responsible operator can evaluate the results provided by the SHM system remotely.
From scientific laboratories to industry
Despite technological advances in applying ultrasound and other methods in SHM systems, existing SHM systems are usually implemented only in scientific laboratories. Why? Because the application of the systems in practice requires specific scientific knowledge about the propagation of ultrasonic guided waves and their interaction with the structure of the studied objects, possible emerging internal defects.
To transfer this scientific progress from laboratories to industry, a 4-year project funded by the European Commission Horizon 2020 Marie Sklodowska-Curie Actions Innovative Training Networks (MSCA-ITN) was launched this year at the Kaunas University of Technology (KTU) K. Baršauskas Ultrasound Research Institute together with international partners.
The aim of “Guided Waves for Structural Health Monitoring (GW4SHM)” project is to combine efficient methods of ultrasonic wave propagation modelling and signal processing for the first time, and to evaluate the reliability of structural health monitoring systems.
The project brings together academic and industry partners. It is a perfect environment to train young researchers and doctoral students and to provide them with interdisciplinary competencies related to SHM. After all, they are the next generation of scientists who can create things that are not yet mentioned even in science fiction, but that is another topic.
The project focuses on assessing structural integrity in the aeronautics, oil industry and transport sectors. Close cooperation between experts with knowledge of mathematics, physics, computer science, electronics allows expanding the possibilities of applying SHM methods while also research application carried out in practice.
The results of this project are of interest to companies in the energy, aviation and transport sectors, such as SHELL, AIRBUS, Dallara Automobili S.p.A., Safran, a supplier of aircraft components and engines from France, and others.
KTU Prof K. Baršauskas Ultrasound Research Institute has over 60 years of experience in fundamental and applied research. Institute activities include interdisciplinary applications of ultrasound in non-standard and extreme conditions, development of new technological measurements solutions and their industrial application.
Over 30 international European Commission’s Framework Programme’s (5,6,7 Framework), Eurostars, Horizon projects, implemented R&D works with international and national businesses, are used in the project.
The project will also use Ultratest equipment that is unique internationally and specialised in the research infrastructure. The research at the Institute is also carried out by doctoral students in electrical and electronic engineering and measurement engineering, as well as master students.
During a pandemic, there is never too much optimism and positive thoughts. It is always useful to remember that pandemics come and go while the scientific results remain.
Let us continue to create and develop a variety of innovative solutions and technologies for a safer present and future for all of us, in normal and pandemic conditions.
Regardless of high-end or complete solutions or technologies, developing and maintaining them still requires and will require the involvement of brilliant, creative and collaborative members of the academic community – future and existing students, lecturers and scientists, industry and society.