# Global Time Step

The global time step (GTS) method can be used to calculate the time step of a model based on the natural frequency of the model.

- /DT/GLOB/Iflag
- $\text{\Delta}{T}_{sca}$

If `Iflag`=1, insert the next line

`Tol_GTS`
`Ncycles`

- $\text{\Delta}{T}_{sca}$
- Scale factor for the element time step
`Tol_GTS`- Convergence tolerance for the iterative algorithm
`Ncycles`- Number cycles between the calculation of the global time step

The global time method is useful in models without a large change in stiffness such as drop test simulations.

- Solid elements: /TETRA4, /TETRA10, hexa with the flags below
- /PROP/SOLID:
`I`_{solid}= 1 (Belytschko), 14 (HA8), 17 (H8C), 24 (HEPH) and 16 (20-noded) - Shell elements:
`I`_{shell}= 1 (Belytschko-Tsay), 12 (Batoz), and 24 (HEPH) - Truss element
- Beam element
- Contact interfaces: TYPE7, TYPE24 (without edge-to-edge option), and TYPE2
with
`Spot`_{flag}=25 and 27