Fibre-reinforced thermoplastics

Abstract

SIMLab aims to develop a constitutive material model for fibre-reinforced thermo plastics. To do this an experimental database is needed. The main goal for this thesis is to provide this database by performing experimental tests, namely uniaxial tension tests, loading-unloading tests and BUP-tests. From the tests, material parameters are identified to serve as calibration coefficients for the new model.

Analyses in the finite element code LS-DYNA are also performed to investigate if already existing material models can capture the response observed in the experimental tests.

The results from the uniaxial tension tests showed the material to be affected by strain rates. The material isalso heavily dependent on the distribution and amount of glass fibres in the material. The fibre-reinforced material is brittle and fractures with little to no necking.

The loading-unloading tests shows signs of viscoelasticity, but this should be further investigated.

The BUP tests performed gives an insight into how the material behaves under a biaxial stress state.

An existing material model in LS-DYNA, *MAT_108, proved to capture many of the traits from the material tests. However it does not incorporate strain rate effects, viscoelasticity or failure criteria.