SOL700 (Dytran) - how to apply time varying arbitrary load on surface ?

Hi Fergus, 

               Your understanding is correct. To apply a time-varying pressure load in SOL700 (Dytran) where each time step has a unique pressure distribution, you can indeed use a single DLOAD case with multiple TLOAD1 entries and TABLED1 functions. This approach allows you to define a time-varying load function for each load step, with appropriate ramp-up and ramp-down transitions between load steps.

Here's a step-by-step guide on how to implement this:

1. Define a Single DLOAD Case:

   • Use a single DLOAD entry to specify the load case. This will be the reference for all the time-varying loads you want to apply.

2. Create TLOAD1 Entries:

   • For each unique time step where the pressure distribution changes, create a TLOAD1 entry. Each TLOAD1 entry will reference a TABLED1 function that defines how the load varies over time.

3. Define TABLED1 Functions:

   • For each TLOAD1 entry, define a corresponding TABLED1 function. This function will describe the load variation over time, including ramp-up and ramp-down phases.
   • The TABLED1 function should start with a ramp-up from zero at the beginning of the load step and ramp down to zero at the end of the load step. This ensures smooth transitions between different load states.

4. Ensure Continuity:

   • Make sure that the end of one load step smoothly transitions into the beginning of the next. This can be achieved by carefully designing the TABLED1 functions to overlap slightly at the transition points.

Hi Shank,

Thank you for your excellent advice, much appreciated.

Fergus