There is a process called auto-frettage which is used to induce compression stresses at the inner lining of gun barrels to restrict crack initiation and propagation due to excessive interval pressures during ballistic firing.
I have defined the thermo-mechanical material properties. modeled the thick cylinder geometry ad 2D disc with a hole at center. I already know the value of compressive stresses on the inner surface of the gun barrel and assign them to the model using predefined field, and am applying the realistic pressure and temperature cycles on the inside surface by using varying amplitude with step time.
I want to study the interaction of pre defined residual stresses, with applied internal pressure and temperature and see how due to applied temperature the residual stresses diminish.
The problem is as soon as temperature is applied the residual stress value drops to zero and only new applied pressure is taken into account for the solution of further steps. How can I tackle this issue ?
I hope I am able to explain my problem clearly, if you still need more details I can provide them as well.
Dear Faisal,
when you apply stresses with a predefined field, you need to ensure that the boundary conditions will maintain that stress in the model. Otherwise lacking any restrictions, all stresses will be relieved as part of the solution.
To put it in a different way, a predefined stress field is not necessarily an equilibrium condition without the BCs to balance it. Abaqus will solve for equilibrium
I hope this will help to solve your problem,
Best regards,
David
- Badges
- Science topic