The reinforced structure of the F/A-18 fighter plane in the Swiss version will be tested in a complex largescale investigation. Realistic stresses, such as those that occur in flight, will be simulated with 68 hydraulic cylinders. This is to prove that the structure meets the relative sharp Swiss application conditions and that it can reach the required service life of 5,000 flying hours. A full scale fatigue test is essential for the qualification and validation of the Swiss reinforcements. Based on a safety factor of 2, 10,000 flying hours must be simulated within 2 years. The test structure is fitted with about 1,100 strain gages. In addition, displacement transducers, temperature sensors and pressure sensors were integrated into the test layout. The signals from these sensors must be measured and saved together with the parameters of the control system.
Specifications were drawn up, based on the customer order, for a control system and for a data acquisition system. The hardware and software requirements were listed in detail in these documents. These specifications formed the basis for all queries and negotiations with possible suppliers.
We placed great value on optimal solutions for the following problems:
Following thorough investigation of various suppliers and systems, we have decided on the following systems: Data acquisition:
Control system:
Interfaces:
Impressive concept for integrating both HBK and FCS systems
RUAG AG is a leading supplier, service provider, and integrator of systems and components for civil and military aviation. The company's core competencies include repair and maintenance work, as well as upgrades, development, manufacture, and integration of subsystems for aircraft and helicopters - and this throughout their entire service life.
Just over 70 years ago, the aerodynamics research department of RUAG's predecessor company, Eidgenössisches Flugzeugwerk F+W, began measuring forces and moments on aircraft. Although the technical possibilities have since been considerably refined, the fundamental questions that engineers ask themselves about understanding physical processes are as relevant today as they were then.
The control cabinets with the control circuits and measuring amplifiers are set up in the vicinity of the test specimen. Short cables can therefore be used for analog measuring signals with less interference effects.
All computers and monitors for operating the test are set up in a control room. The control rooms offers a good overview of the test layout. The connections between the control room and the control cabinets in the hall are implemented via network connections. We therefore only need a few cables for the long connection routes.
Dynamic tests
In normal test operation, the cells are loaded in blocks with 1,000 flying hours (FH) each in 24 hour shift operation. Such a block lasts around a week. A 1,000 FH block includes 5 runs of a loading program which is equivalent to 300 simulated flights or 200 FH. The loading program itself consists of a sequence of 26,900 load cases. There are 2,011 different types of load case.
Static tests
A strain survey is implemented at the end of each 1,000 FH block. The cells are loaded and then released in steps of 10% up to 70% of the maximum load in seven selected load cases.
The entire data acquisition is implemented with the HBK catman®Enterprise software.
During dynamic tests, 200 measuring channels are permanently recorded with a frequency of 10Hz. A measurement series takes about 20 hours and includes the data from a 200 FH cycle.
This produces a data file with around 125 million measured values. This data is then processed in catman® with scripts.
While the test is running, all important test parameters are displayed online on the HBK server PC screen. Plots of interesting sensor data are also displayed.
We use the "Snap Shot" function for measurements during a strain survey. This means that when a specific load level is reached, all active switched measuring channels are measured and saved time-synchronized at the press of a button (about 1,600 measuring channels). A data file normally contains 99 measuring lines. The data is evaluated with catman® scripts once the measurement is complete. Important test parameters are also shown online on the Server PC screen during static measurements.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.