Elemental Time Step Calculations

Time Step Calculations

Critical Time Ste for Shell (2D) Elements

Critical time step:


Figure 1.
Where L is the characteristic length and c is the sound speed:


Figure 2.

Where E is Young's modulus and ρ is Material density.

Critical Time Step for Solid (3D) Elements

Critical time step:
Figure 3.


Where L is the characteristic length and c is the sound speed:


Figure 4.
Additionally:


Figure 5.

Where, E is Young’s modulus, ρ is Material density, 𝜐 is Poisson’s ratio, K is Bulk Modulus, G is Shear Modulus.

Critical Time Step for Beam (1D) Elements

Critical time step:


Figure 6.
Where, L is the characteristic length and 𝑐 is the sound speed.
Figure 7.


Where, E is Young’s modulus and ρ is Material density.


Figure 8.

Critical Time Step for Spring/Discrete Elements



Figure 9.
Where, M is Mass, K is Linear stiffness and C is Damping coefficient.
Note: Refer to the solver manual and theory manual for more details on time step calculation, element library, the characteristic length, element formulation and Hourglass control parameters. HyperMesh element criteria settings provides calculation methods for minimum length of 2D and 3D elements.