what does time period in step means
what does time period in step means
(OP)
Hello,
Am trying to do simulation using dynamics/explicit and I like to know what time period in step means. Because in static I set to default to 1. But in Dynamic if I set to 1 it takes more simulation time than less than 1. I know we can even set more than 1. My question is in time period values. Does these values means seconds or something else. I tried in manual too but I could not find its definition. So if I want to simulate wind load for a minute , do I have to put value of 60 meaning 60 seconds in Time period?
Am trying to do simulation using dynamics/explicit and I like to know what time period in step means. Because in static I set to default to 1. But in Dynamic if I set to 1 it takes more simulation time than less than 1. I know we can even set more than 1. My question is in time period values. Does these values means seconds or something else. I tried in manual too but I could not find its definition. So if I want to simulate wind load for a minute , do I have to put value of 60 meaning 60 seconds in Time period?





RE: what does time period in step means
It depends what system unit you choose for your analysis.
Abaqus has no default system unit, it is a user choice.
You have to choose three base units: length/mass/time.
For instance it can be SI system unit [m/kg/s] or [mm/kg/ms], [mm/ton/s].
When you made your decision you have to define all material properties and loads in correct units.
Young module for steel in [mm/kg/ms] will be in GPa so you put value of 210.0, in [mm/ton/s] it will be in MPa so the value is 210.0e+03
The same rule is for time unit, if you are working in [mm/kg/ms] you have to put value of 60000 for [mm/ton/s] it will be 60.
If you decide to use system unit like [mm/kg/min] (a little crazy but possible) you will have to define step for 1.
So the question is what system unit you use in your simulation?
See here: Getting Started with Abaqus: Interactive Edition, 2.3.1 Units.
Regards,
Bartosz
VIM filetype plugin for Abaqus
https://github.com/gradzikb/vim-abaqus
RE: what does time period in step means
Thank you for the explanation. So if I want to see stress acting on a structure due to wind load, where my SI system is m,kg,sec for 10 minutes then I have to give time period value as 600?
RE: what does time period in step means
You are correct, for SI system unit you have to set value of 600[s].
I have to say it is a lot for explicit analysis which is suitable for transient analysis.
For 10[min] you can expect quite big time of calculation.
Regards,
Bartosz
VIM filetype plugin for Abaqus
https://github.com/gradzikb/vim-abaqus
RE: what does time period in step means
Thanks for the solution. Is the wind analysis is done using this step or someother step like Implicit analysis? Am asking because which is a good step for that so simulation time will be less?