Learning Forum

[nils-erik.sanhen]

Hi everyone,

I’m working on simulating the behavior of a structure under varying loads in PyMAPDL. After reaching certain load limits, I need to make small adjustments in the definition for subsequent load reactions. I’ve written a loop to generate multiple load steps and would like to solve them one by one, extract data, and use it for the next cycle.

However, I’m trying to avoid generating 100 separate analysis files. Since the lssolve command doesn’t seem to support restarts according to the documentation, is there a way to:

1. Use another command to reach this aim?
2. Change something in the defintion of the existing commands?
3. Combine all load steps into a single file?
4. Merge results from individual steps?

Below is my current code for context.

Thanks in advance for any help!

Best regards,
Nils

# Number of load steps
num_loadsteps = 100
final_time = 1

# To create displacement and time lists
time_list = []
displ_list = []

for i in range (1,num_loadsteps+1):

    loadstep_time = final_time / (num_loadsteps) * i
    loadstep_time = f"{loadstep_time:.3f}"

    loadstep_displ = Displ / (num_loadsteps) * i 
    loadstep_displ = f"{loadstep_displ:.3f}"

    displ_list.append(loadstep_displ)
    time_list.append(loadstep_time)
    
mapdl.finish()
mapdl.slashsolu()
mapdl.antype("static")  # Static analysis
# Activate non-linear geometry (optional if large deformations expected)
mapdl.nlgeom("on")

# Perform analysis with multiple load steps
for i in range(1, num_loadsteps + 1):

  
    # Apply displacement for the current load step
    mapdl.d(node="Displ_nodes", lab="UY", value=displ_list[i - 1])
    
    # Set the time for the current load step
    mapdl.time(time = time_list[i - 1])

    # Write the load step definition
    mapdl.lswrite(lsnum=i)  # Store current load step

    # Solve the current load step
    mapdl.lssolve(i,i,1)

    ###
    ###
    #### Do Something here ####
    ###
    ###

# Save the model
mapdl.save()

# Post-process results
mapdl.post1()
mapdl.set(1, "LAST")

[mrife]

Hi nils

Why use load steps files at all, why not just solve?  Also you can ask PyAnsys scripting questions on the specific GitHub Discussion site for specific the PyAnsys project you are using. For PyMAPDL see here https://github.com/ansys/pymapdl/discussions