Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

ABAQUS - Student new to software, keep getting error messages when running job - please help!

Status
Not open for further replies.

JamesPowell

Structural
Sep 5, 2020
11
Hi everyone,

I am currently completing my final year research project on the seismic performance of segmental columns and I am using Abaqus to run the simulations. I am brand new to Abaqus, and since my supervisor has never used the software before I am having to teach everything to myself which is very difficult.

Basically I have some segmental concrete columns reinforced with steel bars and stirrups, encased in steel jackets (modeled by shell elements) and held together with a prestress tendon.
Every time I submit my job to validate my model, I get an error. I have tried to fix the problem by finding solutions online, but I keep getting a new error each time, such as "too many attempts made for this increment" or "time increment required is less than the minimum specified". I also get warnings such as "zero pivots", "negative eigenvalues" or "numerical singularities". Most of the warnings appear to be within the shell elements (steel jackets).

As I am new to the software, I am unsure of what to look for or how to solve this, and I have nobody to ask for help or to look at my model for me. Is anyone able to suggest some solutions?
I have based my model off of a previous study completed by a student in the past (sent to me by my supervisor) and my model appears to be correct after comparing, but I keep getting the errors. I do not have long at all to fix this and get the jobs running, and I am stuck on what to do.

I have attached the .msg file file (for my first model I am using for verification), and I can upload any other files (the .cae, .inp, .odb, and .dat files) if that will be any help in case anyone is able to have a look and possibly see what the cause of the problem is.

Thank you for any help or suggestions - it would be greatly appreciated, I am very stuck at the moment!
 
 https://files.engineering.com/getfile.aspx?folder=0fef076b-fcbc-4678-893f-1615cd519979&file=Job_Test.msg
Replies continue below

Recommended for you

You also have a warning. ***WARNING: DISPLACEMENT INCREMENT FOR CONTACT IS TOO BIG. I think this might be the source of your problem. Be sure you are applying the right displacement or the units you are using are consistent.
 
What could cause this?
Those warnings for the displacement increment being too big are during Step-1 which is where I create H-and F-Outputs 1. The interactions are created in the Initial step, as well as the BCs and the predefined field for the tendon initial stress. The loads are not actually applied until Step-3, so it cannot be an issue with the loads.
I am sure that all instances are placed correctly and have the correct interactions.

How would you model a concrete segment encased in a thin steel jacket? I have a feeling that if I have done anything wrong, it will be the interaction/modelling of these.
 
There is a typical non-convergence error in your message file: "The increment required is less than the minimum specified". But you also have some warnings such as those that may indicate underconstraint: "numerical singularity" and "negative eigenvalues". Check your boundary conditions. Try using automatic stabilization.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor