Thermo-viscoelastic modelling of organic matrix composite behaviour – Application to T700GC/M21

• Modelling of laminated composite strain rate dependency.
• Modelling of laminated composite temperature dependency.
• Influence of matrix sub-Tg transition on the temperature dependency.
• Strain-rate dependency analysis with the time–temperature superposition principle.

The purpose of this study is to propose a thermo-viscoelastic model able to describe the strain rate dependency, from creep to dynamic tests, and temperature dependency, from −100 °C to room temperature, of organic matrix composite materials. A bi-spectral viscoelastic model, proved to be representative of the T700GC/M21 behaviour on a large range of strain rates, is used and improved in this study for temperature dependency. First, thermal residual stresses are introduced and proved not to be sufficient to describe the temperature dependency of the laminate. Subsequently, further to the analysis of the time–temperature superposition principle on DMA tests, the viscoelastic model is improved with the introduction of an Arrhenius like shift factor. The proposed model is proved to be representative and predictive of the strain rate and temperature dependencies of the T700GC/M21 composite material.