R & D Projects

A major focus of activities at INTES is the continuous development of the simulation Software PERMAS. Therefore, INTES is involved in research and development projects on national and international scale.

Insulation and nonlinear damping

Application to an Ariane space launcher payload adapter

Application to an Ariane space launcher payload adapter

In the field of aeronautics and space, the need to attenuate the vibratory environments of equipment on board a launcher and on a helicopter engine is crucial. Progress in the consideration of damping during numerical simulations for predicting dynamic behavior will have a decisive effect on the design of flight equipment (weight reduction, reduction of oversizing, acceleration of the design process and reduction of development costs ...).

The INCAS project falls within this framework, with the objective of developing innovative insulation and damping solutions for complex mechanical systems, as well as software tools for the simulation of their dynamic behavior. Non-linear numerical models have thus been designed, characterized, and validated to precisely model, using the PERMAS tool, the non-linear behavior of the damping devices studied, based on cables or elastomers.

A complementary panel of partners took part in this project with ambitious objectives. Ariane Group and Safran Helicopter Engines thus took part as end users of the solutions designed and tested during this project. Other partners, with whom INTES has worked in close collaboration, include the manufacturers of damping devices Socitec (cable device) and EFJM (elastomer device), the company in charge of project management (AVNIR Engineering) or even Airbus Defense and Space, which provided its expertise in payload comfort and pre-existing solutions.

For the modeling of PID devices under PERMAS, a two-node macroscopic model is used (CONTROL6 element), as illustrated below, to which the appropriate non-linear constitutive law is associated. As part of this project, an innovative method was set up for the modeling of this non-linearity. The peculiarity of the non-linearity of the elastomeric PID resides in the fact that it is dependent on the excitation frequency and characterized only from unit tests. The difficulty for designing such a non-linear model is therefore to have a characterization method adaptable to new designs for which new characterization tests would be carried out.

The principle adopted consists in using rheological sequences (such as Generalized Maxwell models) including non-linear effects. These rheological elements are associated so as to make the behavior of the damping devices correspond with the results of the characterization tests and to allow an extrapolation of this behavior for the torques (static preload, dynamic stress) for which no characterization has been performed.

Correlation Tests / Calculations

From simulations carried out upstream using the PERMAS finite element software, which made it possible to define the excitations to be applied to achieve the desired loads, tests were carried out at scale 1 at the Technological Institute FCBA in Bordeaux (France, 33). These tests made it possible to test the contribution of the various technologies studied during the project on the comfort of the payload. But they also allowed an extensive valuation of the finite element models PERMAS and the digital tools set up during the project by providing a considerable mass of results scanning a wide range of types of loadings: transient, harmonic or random, with bi-axis excitations. All of this data made it possible to judge the performance of the models set up according to the type of loading.

Lift-off / Blastwave

(single-sine)

Comparison between test and simulation results (PERMAS) for the load case relating to "Pressure oscillations"


Booster pressure oscillations

(harmonic)

Comparison between test and simulation results (PERMAS) for the load case related to "Pressure oscillations"

The study of the correlation between test results and simulation results showed a high consistency between the two series of results, especially with respect to the modal behavior by taking into account non-linear damping or the maximal accelerations reached. The video below allows to take into account a complete life cycle test, during which the different flight phases follow one another, with the simulation result corresponding to the same loading cycle. One can note the lift-off phase (loading in mono-sine) at t = 18s, the phase of aerodynamic noise (temporal random loading) at t = 26s or the phase of pressure oscillations (harmonic loading) at t = 1min49s, which is the phase for which the insulation properties of PIDs are most desirable. The result is also very satisfactory since the structure then undergoes only a low level of vibrations, unlike what is observed without the PID devices.

Bi-axis tests (scale 1):

Ariane space launcher payload adapter

OptiAMix
Multi-target-optimized and automated component development for additive manufacturing in the product creation process.
The aim of this joint project is the multi-target optimization of additively manufactured components. The requirements placed on a component and diverging objectives such as load capacity, costs and production effort are weighted in advance and automatically taken into account by a software tool.
This joint project is funded by the BMBF (Bundesministerium für Bildung und Forschung).

SmartLM (2008-2011)
SmartLM will define location-independent software licensing strategies to surmount the effect of virtualisation and grids on software licensing. Current software licensing practices are limiting the acceleration of Grid adoption. The rapid emergence of service and virtualization environments requires a rapid evolution in licensing models.
Traditional licensing models are under pressure from a variety of alternative options that give more negotiation power to users; software users want fair conditions and flexibility. New usage-based models are needed where customers are charged for measurable units relevant to the software they are using and are allowed to flexibly select the best model for their environment. SmartLM will fill in the gap and improve current conditions favoring grids, clouds and virtual environments, aiming to reach a win-win situation between software vendors and users.

The Project has successfully passed the first review in March 2009 where the technical and business requirements for the SmartLM architecture and a first prototype have been presented.

ProGRID (2007-2009)
The goal of the project is to make the grid technology utilizable for cooperative product design and to demonstrate the advantages using selected scenarios. Using the grid technology offers strong potentials for an efficent product development. In case of a virtual validation it is possible to use models that are much more complex. Thus, simulations closer to reality can be carried out since additional parameters can be considered. The effects of changes made to the product model can be predicted more accurately than it was previously possible. Typical user groups in this area are "virtual enterprises" consisting of manufacterers, suppliers, and providers of engineering services that develop new products on a joint basis.