Influence of stress state and temperature on the strength of epoxy resins
11th International Conference on Fracture 2005 (ICF11)
Contribution to Conference
The yield and fracture behaviour of the neat resin was investigated. The parabolic failure criterion was applied to experimental results. From a neat resin slab, specimens for the tensile-, torsion- and compression - tests were manufactured and the failure behaviour of the neat resin due to the actual stress-state was tested at low and elevated temperatures and discussed in detail. The results of the mechanical tests and the fractographic study of the fracture surfaces were correlated to the stress-state dependent ultimate strength of epoxy resins. This plays an important role in fibre reinforced composites, because just after cooling to room temperature the resin matrix is in a tri-axial residual stress-state. The mechanical properties of the neat resin described by the parabolic failure criterion is able to explain the low strain to failure of unidirectional laminates under transverse tensile loading.