• Andreasen, Jens Henrik
• Jensen, Martin
• Jakobsen, Johnny

Abstract

The in-plane thermo-mechanical properties and residual stresses of a CSM E-glass/Epoxy<br/>material are characterised through the use of DSC and TMA. The measured data is used to<br/>generate material models which describe the mechanical behaviour as a function of<br/>conversion and temperature. The in-plane thermal expansion coefficient (a) of the composite<br/>material decreases above the glass transition temperature (Tg), which is compensated<br/>by a higher out of plane deformation above Tg. Comparison of a and chemical<br/>shrinkage measurements suggests that chemical bonds between the polymer matrix and<br/>the glass fibres are formed prior to shrinkage of the epoxy matrix, i.e., at an early processing<br/>stage. This suggests that production of composites with low residual stresses<br/>requires focus on reactivity between the matrix and the sizing rather than the matrix cure<br/>properties. As a consequence, residual stresses in the composite material are mainly a<br/>result of restricted cure shrinkage rather than mismatch between thermal expansion<br/>coefficients.

Topics

• impedance spectroscopy
• polymer
• glass
• glass
• composite
• thermogravimetry
• glass transition temperature
• thermal expansion
• differential scanning calorimetry