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Invalid Restart Step Error (Static to Explicit)

an_02

Structural
Mar 25, 2025
3
Hello everyone,

I have a model where I perform static analysis in the first step and I import those results as initial state to dynamic explicit model. Static Step ran fully and I have followed all the steps to import results to dynamic step, yet I'm always hit with the error "Invalid Restart Step: Step-1.

These are the main steps I followed -
1. Static General Model -
A) defined parts, properties and instances
B) generating restart requests at [frequency=0, Interval =1, no time marks, no overlay] - thought it makes a big .res file
C) defining interactions, BCs as required.
------- THIS MODEL RAN FULLY

2. Dynamic Explicit Model -
A) Copied the Static general model into a new model
B) changed model attributes to read data from my job name in Static analysis and entered "Step-1" as the Step in the next field (as that was the name in my static model)
C) deleted the Step in step module. Created a new Dynamic Explicit step and renamed it so that it doesn't clash with the name "Step-1" of previous model
D) described General contact interaction
E) described BCs required
F) defined the predefined fields as stress states. Defined a predefined field (stress) for each instance.


The restart analysis worked for the explicit model I described above, but with a high energy balance ratio. I later tried making changes to loading rate and mass scaling and it has not worked since (even for those initial parameters where the simulation was working) and I keep getting the error "Invalid Restart Step: Step-1. Change the Model Attributes to a valid analysis step"

Changes I have tried -
1. Changing restart requests in initial Static simulation


There is enough space in my disk, enough RAM, the work directory is correct.

The only thing I can think of is a corrupted .res file but I'm unsure how to check that.

I would love to get input from you all if you have faced this error and how to resolve it. Thank you in advance for your help, I really appreciate it!
 
Last edited:
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There are 2 separate (although partially similar) analysis continuation procedures in Abaqus - restart and import. To change from Abaqus/Standard to Abaqus/Explicit or (vice versa) you need the import procedure. Define initial state field to use it and make sure *IMPORT keyword is included in the input deck.
 
There are 2 separate (although partially similar) analysis continuation procedures in Abaqus - restart and import. To change from Abaqus/Standard to Abaqus/Explicit or (vice versa) you need the import procedure. Define initial state field to use it and make sure *IMPORT keyword is included in the input deck.
Thank you so much for your response and pointing that out. I will try by just defining the initial state predefined field instead of doing both the restart and defining initial state.
 
It is working now. Thanks again, FEA Way.
 

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