Void nucleation and growth in mineral-filled PVC – An experimental and numerical study

• Damage mechanisms in PVC are investigated with SEM and finite element simulations.
• Effects of statistical scatter of cohesive strength are analyzed.
• The softening of the stress–strain curve is related to debonding of particles.
• Void growth on the microscale is shown to be the source of the plastic dilation.
• Numerical analyses of unit cell models capture the experimentally observed behaviour.

The nucleation and growth of voids in mineral-filled PVC have been investigated through experimental and numerical studies. Uniaxial tensile specimens were deformed in tension to different elongation levels and then unloaded. The macroscopic strain fields were recorded by use of digital image correlation. After the test, the microstructure of the deformed specimens was investigated in a scanning electron microscope. It was found that the observed volume strain on the macroscale is related to void growth on the microscale. In addition, finite element simulations were performed on unit cell models representing the microstructure of the material in a simplified manner. The numerical simulations demonstrate macroscopic dilation as a result of void growth. Moreover, the numerical simulations indicate that the experimentally observed stress-softening response of the PVC composite material may result from matrix-particle debonding.