Department Loads Analysis and Design

Control flaps on the intelligent wing model
Three separately controllable flaps allow the wing to virtually evade gusts.

The Load Analysis and Aeroelastic Design department deals with issues that arise in the design of aircraft with regard to aeroelastic properties and aeroelastic requirements. Furthermore, developments in the topic of aircraft loads are performed globally (e.g. for design tasks) and with a focus on dynamic loads (e.g. due to gusts) in the department.

Aeroelastic modeling

When designing an aircraft, it must be ensured that aeroelastic requirements are met. These include sufficient control surface effectiveness and the avoidance of divergence and flutter in the flight envelope to be demonstrated. The Load Analysis and Aeroelastic Design department develops methods for building parametric, aeroelastic analysis models that represent aeroelastic properties of an aircraft configuration. The level of detail of the models depends on the design phase (conceptual, preliminary or detailed design). The modeling is used to analyze conventional configurations (e.g. commercial aircraft) and unconventional configurations (e.g. high-altitude research aircraft).

Load process and load analysis

Determining the loads acting on the aircraft is one of the main tasks in aircraft development. Determination of the loads is crucial for the design and layout of an aircraft, e.g. for sizing of the structure, predicting flight performance and for certification. The department is involved in both the definition of a comprehensive load process and the development of selected load analysis methods. The load process consists of the following steps: load assumptions (definition of load-relevant analysis cases and specific specifications for modeling), execution of load analyses (analysis and simulation) and processing of results, i.e. the evaluation and condensation of the extensive analysis results into relevant data. The load analysis methods developed in the department include both fast methods, which allow a large number of load cases to be analyzed in a short time, and very precise methods, e.g. CFD-based manoeuvre and gust load analyses.

Structural optimization and aeroelastic tailoring

Finally, the calculated loads are used in structural design and optimization procedures. The structural model generated in the parametric modeling is sized with selected load cases. In the sizing process, methods from structural optimization are applied, whereby the restrictions from the field of aeroelasticity (control surface effectiveness, flutter velocity, divergence velocity) are also considered. Special optimization methods are developed for sizing with fibre composite material. Methods are also being developed for an efficient selection of the relevant sizing load cases for the design. Furthermore, certification regulations (e.g. CS25) are taken into account.

Research topics of the department

News from the department


Prof. Dr.-Ing. Wolf-Reiner Krüger

Head of Loads Analysis and Design
German Aerospace Center (DLR)
Institute of Aeroelasticity
Bunsenstraße 10, 37073 Göttingen