Department Structural Dynamics and System Identification

Ground Vibration Test on AIRBUS Beluga XL
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AIRBUS

High-Resolution Measurement of Vibroacoustic Transfer Paths at DLR’s ISTAR in Braunschweig
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Ground vibration testing of helicopter components during final assembly at Airbus Helicopters in Donauwörth
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The Department of Structural Dynamics and System Identification focusses on the dynamics and vibrations of structures in aeronautics, space vehicles and wind energy. Through numerical analyses and experimental investigations, essential mechanisms of vibrations are recognized and the cause-and-effect logic is understood. Efficient measures for damping and control of vibrations are developed with the help of numerical simulations. System identification is utilized for the generation of mathematical substitute models of real technical systems.

The work content ranges from basic research to application in industry. The methods are used in the fields of aviation (i.e. aeroplanes, helicopters, UAVs, elastic wind tunnel models), space travel (i.e. satellites, launch vehicles) and wind energy (rotor blades, wind measurement masts, wind turbines).

The most important research topics are presented below.

Reasearch topics of the department

Research topic

Aeroelastic System Identification

In the research topic of Aeroelastic System Identification, we specialize in the methods for experimental and operational modal analysis. These methods are applied to aircraft, helicopters, EVTOLs and drones during Ground Vibration Testing (GVT), flight vibration testing and wind tunnel testing. The research work includes both, the development of new methods as well as the application of uniquely developed methods in the aerospace sector.

Research topic

Structural Dynamic Experiments

In the research topic Structural Dynamics Testing we deal with the planning, execution and analysis of structural dynamics experiments on small wind tunnel models through to ground vibration tests on large commercial aircraft. Therefore, we constantly developing the necessary software, measurement technology and test methods.

Research topic

Vibroacoustics

In the research topic of Vibroacoustics we deal with the experimental and numerical analysis and control of structure-borne sound. This includes the study of both the generation and propagation of sound in lightweight structures, as well as methods for its reduction. A wide range of measurement, analysis, and simulation techniques are employed for this purpose.

Research infrastructure of the department

Mobile ground and flight vibration testing system (SSVA)

Multi axis vibration simulator (MAVIS)

Technical articles and news from the department

August 30, 2024

Calibration of an instrumentation for load identification in flight experiments

Aircraft should be as light as possible. To achieve this, their primary structure (airframe) is optimized for given operating loads. Precise knowledge of the loads occurring during operation is of particular importance for the sizing of the primary structure.

April 29, 2024

Modal tests in the H135 production line to improve vibration prediction

Helicopters are aircraft with the ability to take off and land vertically. Due to these capabilities, helicopters are often used for fast and local air transport, as required, for example, for rescue operations. The ability to take off and land vertically is achieved by the lift of rotating wings (i.e. rotor blades).

August 18, 2023

Successful demonstration of active flutter suppression

A team of researchers in Europe has succeeded in overcoming an important challenge in aeroelasticity – the suppression of the phenomenon of flutter in an aircraft structure by means of an active control system.

June 16, 2023

Flight Vibration Test – Real-Time Data Analysis using Artificial Intelligence

During flight vibration tests the complex aeroelastic behavior of an aircraft is experimentally identified, to be sure that no critical vibrations can occur within the flight envelope. The DLR Institute of Aeroelasticity has enhanced its flight-testing methods by the use of artificial intelligence to get faster and even more reliable data.

March 21, 2023

Measurements automation in vibroacoustics

Cabin noise is understood as a vibroacoustic problem, in other words, the noise is a direct result of the undesired vibrations of the aircraft fuselage. There are multiple sources that contribute to the fuselage vibration such as engine sound radiation, turbulent boundary layer, engine related vibrations, etc. Hence, understanding what drives the fuselage vibrations and how these contribute to cabin noise is a crucial element of research in vibroacoustics.

December 15, 2022

fs35 Harpyie - Ground Vibration Test for full certification

In October 2022, the Ground Vibration Test (GVT) of the fs35 Harpyie motor glider took place at our structural dynamics laboratory in Göttingen. For two weeks the aircraft of the student research group Akaflieg Stuttgart has been tested extensively.

September 27, 2022

Bend­ing and twist­ing – test­ing high-tech ro­tor blades

With the WiValdi (WindValidation) Wind Energy Research Farm, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is building a research facility in Krummendeich, Lower Saxony, that is unique in this form. It will enable research into the technological aspects of wind energy – as one of the pillars of the energy system of tomorrow – on a real scale.

July 6, 2022

Acceleration sensors for wind measuring mast at the DLR research windfarm (WiValdi)

For the DLR research windfarm (WiValdi) two multi-megawatt wind turbines are currently built in Krummendeich. They will be both instrumented with innovative research sensors. To characterize the wind field there is already a 150m high IEC conform wind measurement mast available besides others like lidars that will be installed on the wind turbines.

May 31, 2022

1500 sensors for the rotor blades of the future

Rotor blades are one of the most important components of a wind turbine. They can be up to 70 metres long and weigh between 15 and 20 tonnes. In order to operate wind turbines more efficiently in the future and also to be able to use them in locations that are less wind-intensive, even larger and at the same time lighter blades are needed.

April 20, 2022

CO₂-neutral flying - how can aeroelasticity contribute to this?

In the future, aircraft will have to fly in a much more environmentally friendly manner in order to contribute to meeting the targets for limiting global warming. With the aim of testing new innovative engines, DLR has added a new research aircraft, a Do228-202, to its fleet. On this aircraft, electric engines powered by a hydrogen fuel cell are to be tested.

January 27, 2022

No more vibrations! - Viscoelastic damping design for the reduction of aircraft vibrations with elastomers

Anyone who has ever flown in an airplane knows this problem: You want to read a book or to snooze without being disturbed, but around you there is an annoying bucking and a humming noise. The sources of these disturbing events are usually wing or fuselage vibrations which are amongst others caused by wind gusts, turbulence or by engine operation.

November 5, 2021

How much noise? - cabin acoustics of future aircraft

Aircraft cause considerable noise, both to the outside world and inside the cabin. The INTONATE project is investigating how cabin noise is created and how it affects flight comfort. The main goal is to set up a digital thread for calculating the cabin acoustics of aircrafts still in the design phase.

July 2, 2021

DLR conducts vibration tests on ISTAR

Every aircraft vibrates in flight and during take-off and landing. It is important that critical vibration events are avoided. The Ground Vibration Test (GVT) is a key element to enable a new aircraft to receive its certificate of airworthiness.

Contact

Dr.-Ing. Marc Böswald

Head of Structural Dynamics and System Identification
German Aerospace Center (DLR)
Institute of Aeroelasticity
Bunsenstraße 10, 37073 Göttingen
Germany