Obiettivo In order to describe the external and internal deformation states of air springs several FE-related tools (in particular: new material laws) were developed. The calculations were largely based on measurements on different components of the air spring wall. In particular a new inelastic formulation for the rubber compound was developed by the Universitaet Hannover on the basis of a series of cyclic tensile and shear measurements on rubber samples carried out by Akzo. The constitutive equations reflect most of the observed elastic and inelastic rubber characteristics: elastic: 'Neo-Hookean' base characteristic damage: (recoverable) stiffness reduction after 'prestretching' hysteresis: direction-dependent additional stresses non-viscous: no strain-rate related effects Other material models were defined for the description of complete cord layers, individual cords and filament material. In FE calculations stress and strain distributions within the air spring wall were calculated for comparison with a simultaneously established fatigue test data base. Fatigue tests were carried out on different air spring tyres and on adapted pressurized cross-ply tubes. Although a comprehensive correlation analysis between the calculated stress strain data and the tested failure behaviour of air springs could not be concluded within the project framework a good correspondence could be found between areas of calculated maximum shear stress and the origin of observed fracture phenomena.For the design and optimization of products based on rubber-cord composites the knowledge of internal micromechanics and related fatigue mechanisms under application loadings is of fundamental importance. Several Finite Element programmes (e.g; ADINA, MARC, ABACUS) offer methods for a realistic simulation of deformations and some internal stresses and strains. Composite structures though are usually modelled using transverse isotropic elemental formulations, which only allow a macroscopic description of the internal deformation states. These methods do not take into account the helical geometry and the nonlinear behaviour of the cords. Also, most interactions between the cords and the surrounding rubber are ignored. Within the project new experimental techniques and numerical tools are to be developed to enable a better modelling of stress and deformation states of thin walled rubber cord composites (e.g. air bellows) Campo scientifico engineering and technologymaterials engineeringcompositesnatural sciencesmathematicspure mathematicsgeometrysocial scienceslaw Programma(i) FP2-BRITE/EURAM 1 - Specific research and technological development programme (EEC) in the fields of industrial manufacturing technologies and advanced materials applications (BRITE/EURAM), 1989-1992 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento Data not available Coordinatore Contitech Luftfedersysteme Gmbh Contributo UE Nessun dato Indirizzo Philipsbornstrasse 1 3000 HANNOVER Germania Mostra sulla mappa Costo totale Nessun dato Partecipanti (3) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto AKZO Paesi Bassi Contributo UE Nessun dato Indirizzo Mostra sulla mappa Costo totale Nessun dato Institute of Mechanics of Materials and Geostructures SA Grecia Contributo UE Nessun dato Indirizzo Askiton Str. 22 15236 PENDELI Mostra sulla mappa Costo totale Nessun dato Universität Hannover Germania Contributo UE Nessun dato Indirizzo Appelstraße 11 3000 Hannover Mostra sulla mappa Costo totale Nessun dato