The time interval is used in the Newmark implicit time history integration scheme to solve the dynamic finite element equation in PLAXIS code. The time interval should be not exceeded the critical time interval which depends on the the maximum frequency of input motion and the size of the finite element mesh in order to obtain reliable solution and ensure that the wave does not move through a single step distance larger than the minimum dimension of tan element. I suggest if you could review the PLAXIS manual – scientific part- section 7: Dynamic and you will find how to compute the critical time interval.

The time step (time interval) depends on the type of analysis. The time step in explicit analysis must be less than the courant time step (time it takes a sound wave to travel across an element) which can be determined by an equation. In Implicit transient analysis there is no inherent limit on the size of the time step. As such, implicit time steps are generally several orders of magnitude larger than explicit time steps.

Thanks so much proffessors

your recommendations where very helpfully for me

regards

I have another question, if you can help me please

I am entering a line displacement as harmonic signal, with accelerations data type. It has an amplitude of 0,2, frequency of 1 [Hz] and period of 1 [s]. The dynamic time interval it is 25 seconds, so it has 25 cyclic. My question is, how can i correctly define the correct number of max steps and number of substeps? I know that is important to define the correct number of both because my results vary to much if i put any different number of max steps and number of substeps.

Dr. Saad Faik Abbas Al-Wakel Junied Bakr

https://stackoverflow.com/questions/33113295/how-to-aggregate-data-by-a-dynamic-time-interval