Project Details
Projekt
Residual Stressesin intrinsic hybrid laminates, detection, modification and consideration in manufacturing and the numeric damage modeling
Applicant
Professor Dr.-Ing. Michael Sinapius
Subject Area
Lightweight Construction, Textile Technology
Plastics Engineering
Plastics Engineering
Term
from 2014 to 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 256131096
The different thermal properties of the components as well as the anisotropy of hybrid CFRP-metal-composites lead to intrinsic high residual stresses during the production processes reducing in turn the strength of the hybrid composite. The project aims to investigate measures to reduce the interlaminar stresses. Therefore, measurement technologies are investigated for measuring the existing or nascent residual stresses. The focus lies on the application of fiber optical sensors being directly integrated into the uncured fibre reinforced polymer. Measures for modifying the level of residual stresses are investigated subsequently. Parametric mass screenings reveal the cause-effect relationships between the material parameters and the process parameters as well as the interlaminar residual stresses.Beside the intrinsic stresses asymmetric layups lead to process-induced deformations like curvatures or deflections. Curved structures exhibit significant complex stress states.The developed measurement principle will be adapted such that beside the determination of the residual stresses statements about the sources of process-induced deformation can be made. The achieved perceptions from the first funding period about the origin of residual stresses, the influence of different intrinsic and extrinsic factors are used to discover the cause-effect relationships between the process-induced deformation evoked by the structural curvature, the asymmetry, and the embedded residual stresses. Beside measures for reducing these stresses compensating methods for producing dimensionally accurate structures are investigated for hybrid structures. The developed compensating methods are used to manufacture accurate flat asymmetric coupons for CAI investigations. The effect on the damage behavior will be investigated experimentally.
DFG Programme
Priority Programmes
