Strain rate dependence of resins.
Plastics have the property of becoming harder as the deformation speed increases.
Tthis is called strain rate dependence.
If the phenomenon you want to predict becomes faster, you cannot express only by the normal resin characteristics (low-speed stress-strain curve).
Asahi Kasei’s unique material model
Crystalline resin represented by polyamide has a crystalline part and an amorphous part as shown in the figure.
When a non-reinforced dumbbell-shaped specimen of polyamide is pulled, then necking occurs in this way, which causes ductile fracturing.
This is because the polymer of the amorphous part is stretched and the resin has the characteristic that the fracture occurs at the boundary between the crystalline part and the amorphous part.
We have developed a material model that considers such microscopic damage and applied it to impact analysis so that we can predict the failure mode and the amount of energy absorbed at the time of failure.
Fig.4 Material model considering the craze effect