Which LS-DYNA solver are you using? Are you running SMP or MPP? If MPP, a meaningful error message may be written in one of the mesXXXX files. Please check all mesXXXX files.
We have seen this problem before where the solver hangs without an error message and the calculation does not move forward. In this case, I would try running with another solver revision. You can download different revisions here:
You will find the latest release (R14) here:
Let me know how it goes.