Effects of gauge length and strain rate on fracture toughness of polyethylene terephthalate glycol (PETG) film using the Essential Work of Fracture analysis
Ecy. Ching et al., Effects of gauge length and strain rate on fracture toughness of polyethylene terephthalate glycol (PETG) film using the Essential Work of Fracture analysis, POLYM ENG S, 40(2), 2000, pp. 310-319
Essential Work of Fracture (EWF) analysis was used to study the fracture to
ughness of a PETG film. In the study of the gauge length (Z) effect on the
specific essential work (w(e)) using Z = 50, 100, 150, 200 and 250 mm, it i
s observed that w(e) is independent of gauge length, except that a slightly
lower w(e) value was measured for Z = 50 mm. Interestingly, for specimens
with long gauge lengths (Z greater than or equal to 150 mm in this study),
brittle fracture occurred. The minimum ligament length at which ductile/bri
ttle transition took place was observed to decrease with increasing gauge l
ength. There is a small strain rate effect on w(e) with loading rates less
than 1 mm/min. But with higher loading rates, w(e) showed no strain rate se
nsitivity.