Andrea Resente is a phd student of the Department of Industrial Engineering of the University of Padova (Italy). He started his phd in 2022, after the graduation in Mechanical Engineering at the University of Padova. The partner company of his phd is Electrolux SPA, which operates in the white goods industry. Andrea's main research topic is the design of industrial components using composite materials with a recycled polymeric matrix.
An experimental investigation of the fatigue behaviour of notched and unnotched specimens made of 25% wt. short glass fibre reinforced recycled Polypropylene filled with mineral filler is presented.
To this end, plain and double-edge notched specimens (with notch radius ranging from 0.25 mm to 10 mm) were produced by injection moulding and tested under tension-tension fatigue, highlighting the effect of the notch root radius and the notch geometry. During the fatigue test, the damage evolution was monitored using a traveling microscope to define the number of cycles spent for the fatigue crack nucleation. The fracture surfaces were careful analysed both at the macroscopic and microscopic level, discussing the analogies existing between plain and notched specimens.
The fatigue tests were reanalysed in terms of net stress amplitude defining the traditional stress-life curves, each of them fitted on data derived for a given specimen geometry. Then, an energy-based approach was proposed for the assessment of fatigue life spent for the crack nucleation. The model is conceptually based on the actual damage evolution observed both during the fatigue tests and reported in the technical literature: the initiation of a macro crack results from the accumulation of damage in the matrix. Thus, the strain energy density evaluated in the matrix and averaged on a structural volume embracing the notch tip was adopted as fatigue damage index to correlate in a single scatter band the fatigue data of unnotched and notched specimens.
|Wednesday 29th November
S04-1 Composites, elastomers and adhesive bonding
32 - Fatigue behaviour of 25% wt. short glass fibre reinforced recycled Polypropylene filled with mineral filler in presence of notches