EFFECT OF STRAIN RATE ON STATIC ELASTIC RESPONSE OF GLASS-POLYESTER COMPOSITE. PART 2: ANALYSIS OF EXPERIMENTAL RESULTS
Mateusz Kozioł, Szymon Latusek
Quarterly No. 1, 2023 pages 44-49
DOI:
keywords: glass-polyester laminate, static bending, strain rate, normal stress, elastic modulus in bending, energy dissipation
abstract This paper is the second part of the study aimed at evaluating the influence of the strain rate of the plain weave reinforced GFRP laminate, in the non-destructive static three-point bending test, on the material’s stress response. It was found that the stress level during the entire course of the deflection increases with the increase of the strain rate. The relative change in the stress level is comparable for the 0/90 and 45/45 fiber orientations. As the loading speed increases, the elastic modulus of the material also increases. For an increase in the strain rate from 1.11∙10-3 to 5.57∙10-1 1/s, the increase is 10% for the 0/90 fiber arrangement and 17.7% for the 45/45 fiber arrangement. The dependence of the modulus on the strain rate is logarithmic. Based on the theoretical analysis, the cause of the observed effects of the strain rate on the material response was attributed to the viscoelastic behavior of the matrix (cured polymer resin) and the viscoelastic behavior of the fibers system at the level of the laminate mesostructure.