Twas thus it spoke,
“O rasher, bolder race Than all those daring deeds have tempted fate, Thou, whom no labours tame Nor war’s fell stroke, nor rest wilt grant on human toils
to wait: Since these forbidden bounds by thee are broke who durst my Virgin Seas to violate, Which long
I guarded, where I ne’er allow plowing to foreign or to native prow.”
Five centuries separate these two events, but the spirit, the tenacity and the courage is the same, it means that we do not settle for our corner of comfort, it is a challenge to open up new horizons, it is the will to overcome new challenges, it is the determination to fashion by our own hand the future of our present, it is the desire not to be just another grain of sand washed away by the waves of time, which led us to make our presence known both in the air and the space.
The world today is much more than the chaos, the tragedies and the calamities depicted by the media on a daily basis; on the contrary, it is a world brimming with new opportunities. It is up to us to choose to let ourselves be submerged by the constant waves of opportunities that wash by us or to ride their crest. The latter was the choice made by LABET – Aerospace and Thermodynamic Testing Laboratory of ISQ
At the time, ESA (European Space Agency) was developing its IXV (Intermediate eXperimental Vehicle) programme, the prototype of a space shuttle to make an initial flight to collect data and test new materials, resistant to the extremely adverse conditions of re-entry into the atmosphere. Were we knowledgeable and experienced in this area? We were not, but we had experience in testing and mastered the universal languages of engineering: mathematics and physics.
We also knew that this challenge would be our best opportunity to internationalise our aerospace activity and thus take a qualitative and quantitative leap which our market would not allow.
Therefore, after conducting a summary study of the investments needed, and their availability in view of future business opportunities, we began to implement them. We were careful to try and develop, whenever possible, all the activities internally, including those related to data control and acquisition, so that it was possible to configure independently, at any time, the equipment for our clients’ future specific needs.
We purchased a 10-6 mbar high vacuum double body chamber to enable external heating or cooling, equipped with various access flanges for future instrumentation needs, passage of electric power and cryogenic tubing. Vacuum tests under temperatures from -150°C to +1200°C have already been conducted in this chamber, as well as the determination of specific vacuum heat and extreme temperatures of various materials used in the aerospace industry.
The existence of this multipurpose vacuum chamber and its easy move and adjustment to customised tests made it a
highly sought-after piece of equipment, particularly on the international market, and led to a growing domestic market for new components, not just for the aerospace industry, but also for other sectors of new material and technological development, enabling tests to be performed at lower costs and without the need to travel to foreign labs.
At the time, a shaker with a horizontal table was also acquired, as was a guided vertical expander with maximum power of about 290Kw, equipped with an LMS data acquisition system (standard for the aerospace industry), which enables, in addition to conventional Seno and Random tests, Operational Modal Analysis tests to be performed for fine-tuning mathematical design models. This shaker was also equipped with a climatic chamber for vibration tests with temperature control between -40°C and +150°C.
We performed the Operational Modal Analysis tests for various thermal protection panels in this shaker, as well
as the IXV nose, to determine the natural specific frequencies and their respective modal forms. In this modal analysis, we determined the first natural frequency was within the 60Hz range, which coincided with the frequency of the Vega launcher itself.
The Italian project team was immediately alerted to this coincidence which would have negative consequences for the IXV launch.
Therefore, by changing the compaction of the insulating silicon fibres, it waspossible to modify the rigidity of this “IXV nose”, making its first resonance module move away from the critical 60 Hz range.
In addition to aerospace tests, e.g. those performed on the new panels of the cryogenic tanks of the new Ariane (CUST – Cryogenic Upper Stage Tanks) and the new carbon fibre exhaust nozzles for satellites and craft, many other tests have been performed in this shaker, both for international and domestic industries (automotive, components for satellites, electrical equipment, certification of aircraft components for the Air Force, military equipment, cold production units, among others), which now have easy access to one of the largest shakers in the Iberian Peninsula and Europe.
Also under the IXV programme, the need for traction tests arose for stand-offs, insulating panel fasteners to the
craft outer body. But, once again, this test required temperatures varying from room temperature to 1000ºC. For this
purpose a specific customised system was entirely designed and developed at LABET. It was also necessary to develop a whole system to enable the study of gas migration and measurement of permeability inside the IXV insulating panels in order to ensure their integrity during the rapid depression caused by the quick climb of the launcher.
Under the IXV certification programme, it was LABET’s responsibility to perform the thermal tests for re-entry into the atmosphere on the “nose” and the insulating panels of the craft’s lower belly. To this end, a second specific design was made at LABET, a muffle capable of reaching 1200°C and temperature increase ramps, identical to the temperatures expected during re-entry. This test and its monitoring enabled the expected behaviour to be analysed in terms of temperature distribution, both inside the re-entry protection panels and on the interface of the craft’s external surface insulation, during and after this wide transient regime during re-entry.
This was a short assignment with great impact”, said Gaele Winters, ESA’s Launch Director, at the time. It is thus that, on 11 February 2015, after a short, but very important and successful mission, Portugal stands on an equal
footing alongside its European partners in breaking new ground.
EMPOWERING TO ALSO RESPOND TO THE CHALLENGES OF AERONAUTICS
But the dream has not stopped here. Thanks to the experience gained by ISQ and the success achieved in this kind
of test, a new, important door began to open. The aeronautical sector also started to look on us as a partner for testing aeronautical components. And the challenge came from an aeronautical manufacturer in one of the sector’s world giants, Embraer.
We were set a fresh challenge: To design and build a customised laboratory for testing aeronautical structures, capable of conducting static and fatigue tests on large aircraft components, as well as developing a whole new specific testing programme and sequence for this area.
Following technical visits to Embraer and other aeronautical testing labs, we concluded that the most advanced
systems, used by the main manufacturers, are the MTS hydraulics control systems and the HBM data acquisition system, so ISQ opted for these.
At the same time, a structured floor was designed and built, as was the remaining infrastructure needed in a lab of this kind. Simultaneously, LABET, together with other ISQ labs and teams and in partnership with Embraer’s engineers, began to develop the project and the infrastructure required for the particular test we were going to perform: testing a half-wing in composite material. Just over a year later, the lab, endowed with the MTS hydraulics system and the HBM data acquisition system, was accredited to AS/EN 9100 standard, and audited and approved by Embraer.
At the same time, the design of the supporting RIGs for the test article was complemented and the building of
these welded metal structures began. Despite its size and weight, the design accuracy and the quality of the welds
with full penetration to ensure the perfec-t positioning of the test article and a resistance to fatigue tests (several million cycles) required full monitoring during the construction stage by ISQ welding and- 100% ultrasound control specialists.
In mid 2015, everything was finally ready for the tests to the half-wing to start.
Surrounded by a team of engineers from Embraer Compósitos in Évora and Embraer S.A. in Brazil, who had designed and built this half-wing, and by another team from the testing department of Embraer S.A., Brazil, the long-awaited and most critical time had come. Never had the pressing of an Enter key been so harrowing…
A completely new test, never done before in Portugal, operated by a complex hydraulics control programme,
where thousands of variables were introduced, from PID configuration (feedback control loop Proportional
Integral Derivate), all the loads that made up the various flights, the flight combinations and the calibration
data of all parameters, together with the prediction and definition of all alarm and/or shutdown thresholds, in the event of an anomaly, all this, despite many, repeated validations by the whole LABET testing team, always left a question hanging when it came to pressing Enter. Has anything failed or is anything missing?
Any fault could simply destroy the test article, a unique, priceless piece, and the whole ISQ investment and credibility would be ruined then. However, confident in the excellent team and the professionalism demonstrated
over time, in so many new, non-standard tests successfully performed, certain that in this case we had not given Murphy’s Law any leeway, Enter was pressed…
And everything went smoothly!
The static tests were very successful, with no programming faults in the entire MTS hydraulics control or HBM data acquisition control systems. Once again, LABET had successfully achieved its goal, and ISQ once again lived up to its long tradition of honouring its commitments and overcoming the technical challenges set by its clients, turning what seemed impossible and a mere dream into a new palpable reality on which our future will continue to build.
AND SPEAKING ABOUT THE FUTURE…
Speaking about the future, a new and promising opportunity has been seized through a collaboration protocol between two major Portuguese engineering institutions, ISQ and CEIIA (Centre of Excellence and Innovation in the
As an initial practical result of this partnership, thanks to the experience acquired with the half-wing test, ISQ began to perform the qualification tests
for some components, designed and developed for the new Embraer KC 390 military transport airplane. Shock
and static limit tests have already been successfully performed on the elevator of this aircraft, with fatigue and Load Bearing traction tests now being underway on various representative test specimens of this model.
Therefore, by combining complementary knowledge, joining forces, working as a team and believing in ourselves, we
managed to position Portugal in its welldeserved place in history, as the poet justly sings…