Aging aircrafts, transmission pipelines, bridges, railways, power plants and other large sections of our civilian and defense infrastructure are known to have far exceed their design lifetime. This has driven to an increasing demand of novel non-destructive evaluation (NDE) systems. NDE is an important research area that comprises the development of technologies and methodologies for assessing the structural integrity of critical materials, components and structures without affecting its future usefulness.
Gathering researchers from the Instrumentation and Measurements group, the Applied Electromagnetics group and the Optical Networking group, under the coordination of Helena Ramos, this internal IT project intended to increase accuracy and reliability to the inspection procedure by integrating complementary information obtained with two NDE techniques. The aim was to propose novel methods that push the state of art in NDE with a goal to monitor, detect and characterize hidden damage in carbon fiber polymer reinforced (CFRP) composites.
CFRP materials are increasingly being used in structures due to their lighter weight and improved strength, when compared to metals, in addition to their capability to be readily formed into custom shapes to meet unique requirements. However, NDE techniques have been problematic to employ in these new materials.
The RELIM research team joined two complementary NDE techniques: eddy current testing (ECT) and guided wave ultrasonic testing (GWUT). These two techniques were chosen, not only because they are complementary, but also because GWUT possesses propagation capabilities that enable inspection to be carried out with reduced scanning, allowing detection of damages in hidden parts of the structure or with difficult access. In addition, the use of tiny piezoelectric as sensors and actuators with GWUT is foreseen as a step forward in the direction of the development of a Structural Health Monitoring (SHM) evaluation. It is expected that in the near future, SHM shall bring huge costs and safety savings to different industries.
Photo: Locating real time impacts with PZT transducers in CFRP plates. After dropping the impactor through a tube, the guided wave signals obtained by the four PZTs are acquired by the digital oscilloscope.
Astronomers and software specialists from all over the world have completed the SKA´s First Science Data Challenge (SDC1), showcasing the community´s enthusiasm to prepare for the SKA´s complex and large data volumes. The challenge was held on July 15, in SKA Global Headquarters, Jodrell Bank, UK.
Nine teams representing 12 institutions' Consortia in 8 countries took part in the challenge. They were invited to analyse a series of high resolution images of the radio sky created through data simulations, and use software of their choosing to find, identify and classify the sources.
ENGAGE SKA from Portugal was ranked on the Top 3 of the Challenges. "This is very encouraging. The Challenge was already running for a couple of months, when we started the competition. For that reason, we adopted a direct approach to the problem using a set of tools that were already publicly available and could be fine-tuned to the problem and were also used by the top teams. It was a real challenge to deal with such large data set, but we are happy with our participation and with the results obtained", said Bruno Coelho, AENEAS fellow and researcher at IT, ENGAGE SKA, chairing the SDC1 work in Portugal.
"This is very exciting, it shows Portugal is creating an avenue for Big Data science mining, developing the skills and capacities required to handle the massive information expected from the SKA in the near future", added Domingos Barbosa, coordinator of ENGAGE SKA and also a researcher at IT.
The images show how the SKA's mid-frequency array, to be located in South Africa, would see the radio sky at three different frequencies (560 MHz, 1.4 GHz and 9.2 GHz), over three different exposure times: eight hours, 100 hours and 1000 hours. Each of the nine images filled 4GBytes (or 1074 MegaPixels).
Photo: A snapshot from the SKA Science Data Challenge image, showing a large Active Galactic Nucleus (AGN) as if observed by SKA-mid at 1.4 GHz. (Credit: SKA Organisation)