Hi everyone,

I used to use Abaqus/Standard as my analysis tool. But recently I face some problems then turn to Abaqus/Explicit. So I start to browse User Manual. One thing I'm confused is that how dose it calculate stable time increment? Below I try to post two paragraph from Abaqus Aanlysis User's Guide 2016.

The first one describes Abaqus/Explicit is conditionally stable if stable time increment equal less than 2 / (highest frequency).

However, the second one mentions Abaqua/Explicit see dynamics problem as dilatational wave problem. Also apply the wave speed and the smallest element dimension to calculate stable time increment.

The second gives the specific rules to obtain stable time increment. But what about the first one? Does that join the calculation of time increment? Or it just help to modify the result from second one? I mean if the result of second > (Lmin) / (wave speed) is larger than first one, system will choose first one to prevent unstable.

Thanks,

Adam Cheng