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Modeling of single-lap bolt-joint (urgent)

Modeling of single-lap bolt-joint (urgent)

Modeling of single-lap bolt-joint (urgent)

(OP)
Hi all,

I am a new user of ABAQUS. Now, I am using version 6.8 (CAE) to model a single-lap bolt-joint (see the attached files: 1-bolt.cae, job-1.inp, job-1.dat and job-1.msg). When I run the model, I get the following message "the system matrix has 2 negative eigenvalues". It seems that the reason for the warning message relates to the instability. I try to reduce the increment time but the problem still persists. It would appreciate if someone can help me to solve this.

Thank you very much.

NDH   

RE: Modeling of single-lap bolt-joint (urgent)

You posted the *.DAT only.  It states:
"                              WITH     1 ERROR MESSAGES ON THE MSG FILE
                              AND    130 WARNING MESSAGES ON THE MSG FILE"

My guess is that the 2 parts are disconnected and there is a rigid body motion.  Be sure to constrain all 6 DOFs and to have connectivity between the models through coupling or contact.  I hope this helps.

Rob Stupplebeen

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