example for each model and result of bolt pretension approach in Code_Aster, it seems a pretension force is over-estimated due to relaxing compared to complete and full model with threads and torque load at nuts.
The stress field shown in your reference doesnāt have any sense to me because the preload do not propagate across the entire bolt shaft.
ccx Solves properly if BC are done carefully so model can freely expand. I have used recomended preload value according to nasa. (65%FtyAt)= .65900314=183.783KN with great agreement at the end of preloading step.
.65*900=585MPa
when a model results match analytical does not it means can be truthfully and trusted, only by full and complete model with threads and torque loads can be predicted. and represent well of preload bolts behavior. Thereās many papers and report related to this, and initial condition type stress more reasonable than others. Slide of an opposite displacement at nut seems to be better probably, effective bolt diameter due to threads length in shear plane also can be considered.
I can only suggest you stop reading/referring papers you donāt understand and start putting things into practiceā¦.. , against analytical solutions preferably. (That way you donāt need to ask other users to do your job with External solver comparisons)
-You will constate how good or poor is your understanding.
-You will understand the importance of increasing complexity gradually and accompanied with precise reference values to compare with.
-You will appreciate the analytical solutions and how accurate they can be even with their raw approximations.
-You will learn how a complex problem can be simplified.
-Your set up will be better grounded before going further.
-You will understand the computational cost of introducing details that are unnecessary or irrelevant to the aim of a specific problem.
-You will develop skills to differentiate better between raw but profitable results among non-sense ones.
And finally, I would mention you will appreciate the effort of otherās contribution no matter how simple they look like but thatās not warrantee so forget it.
where i says full model of bolt with a thread and torque loads is practical? only noticed the reasonable approach from many proposed and used complex analysis as benchmark and references.
other threads is clear i have no access to commercial solver, but i can do by myself with another opensource solver probably. I tested about ten shapes of thin-walled sections, and four of them failed to convergence in CalculiX so i guessed related to solver algorithm. Is there are my personal benefit only, not community., did you mean analytical by hand calculation of complex phenomena of buckling including plasticity, and self-contact or crushing maybe? as i understand only by physical test can be verified.
look out reinforced beam thread previously, how can a simple boundary condition setup is kept secretly and left the problem unsolved. Or clip contact problem since mortar contact with hard type shown working well without any tricks in mesh and time steps.
yea, appreciate your personal screenshot and keep ignoring other works as non-sense even published by reputable institution maybe, thatās not my culture sorry.