Material tests at quasi static and high strain rates

[svishal03]

Hi,

I'm attaching a file which have the stress strain curves of same material at quasi static and high strain rates.


See materials on page 1 and page 2.

Both are same materials.

The curve on page 1 is obtained at quasi static strain rate and the curve on page 2 is obtained at high strain rate.

Both have almost the same ultimate stress indicating that material is not strain rate dependent.

However, there is some change in elastic limit. Material at high strain rate has a lower elastic limit than one at high strain rate as well as there is some difference in slopes at quasi static and medium strain rates.

What can we infer why- changes in slope and elastic limit are occurring?

 

[Valerie Park]

The change in slope and elastic limit of the stress-strain curves can be attributed to the different strain rate conditions. At high strain rates, the material will experience a greater amount of deformation due to the increased strain rate. This can lead to a decrease in the elastic limit and a change in the slope of the curve. The change in the elastic limit is due to the rate at which the material is being deformed, as higher strain rates will cause the material to deform more quickly than at lower strain rates. The change in the slope can be due to a number of factors, such as increased work hardening or increased friction between the material and its environment.