Elastomer materials are now firmly established in technical applications and are used, among others, for bearings, hoses, tyres, and seals. Geometrically complex profiles comprised of various fibre-reinforced and thermally stable elastomers are used with the aid of other polymer materials for the manufacture of aircraft door seals. Their purpose is to seal the interior cabin of the aircraft against the atmospheric conditions, whereby the sealing effect should be as unaffected as possible by external disturbing influences. Depending on the flight altitude, the differential pressure in the fuselage of the aircraft and the temperature are distinct from flight to ground conditions. These differences influence the local stresses of the door seals and thus modify the required special design solutions. The main purpose of this work is to provide a suitable methodology to quantify and understand the variables behind the seal performance for design development with the help of the commercial CAE tools. Based on the large strain formalism of continuum mechanics, the characterization of the material properties is used as the initial step to consider the behaviour of an elastomeric seal in a physically consistent manner. Since elastomers and polymers belong to the class of thermo-viscoelastic materials, changes in the contact stress distribution may also occur due to relaxation. By establishing the mission profile of a long-range aircraft from ground to flight conditions, the analysis steps are built in a sequence of static, dynamic, and temperature-influenced solutions. For simulation purposes, 2D models are used after extrapolation techniques to assume a representative mesh size using the FEM. From a conceptual inflatable seal design used for passenger and cargo doors, the simulations are parametrised in a virtual environment for computational experiments. Despite the lack of validation of the analysis methods on a component level, Design of Experiments (DOE) provides the assessment of the inputs that are correlated to the seal performance indicators related to leakage, collapse, force, safety factors, and residual displacement. These indicators depend on model outputs such as stress, displacement, and contact pressure which are modified based on the choice of the 'best' design through Parametric Optimisation techniques. The results show that it is possible to extract the optimal solution from slightly different design candidates or variants by combining the capabilities of two algorithms: NSGA-II and LSRGR. An objective function that reduces air leakage, while minimising the reaction force when the door closes, is covered by three critical loading conditions governed by relative displacements of the striker. Performance comparisons are ultimately computed with the DOE re-analysis of 500 load cases that were initially generated by the optimal Latin Hypercube Sampling (LHS) of 11 inputs.    «

Elastomer materials are now firmly established in technical applications and are used, among others, for bearings, hoses, tyres, and seals. Geometrically complex profiles comprised of various fibre-reinforced and thermally stable elastomers are used with the aid of other polymer materials for the manufacture of aircraft door seals. Their purpose is to seal the interior cabin of the aircraft against the atmospheric conditions, whereby the sealing effect should be as unaffected as possible by exte...    »