estimating residual stress due to cold bending
estimating residual stress due to cold bending
(OP)
Hi everyone,
would someone be willing to point me in the right direction for estimating residual stresses in sheetmetal plates due to cold bending? the only case i need to learn about is when a 90 degrees flange is set. relevant articles or forum threads? is this usually done using some set of rules or maybe FEA?
any help is very welcome.
Thanks,
Mark
would someone be willing to point me in the right direction for estimating residual stresses in sheetmetal plates due to cold bending? the only case i need to learn about is when a 90 degrees flange is set. relevant articles or forum threads? is this usually done using some set of rules or maybe FEA?
any help is very welcome.
Thanks,
Mark






RE: estimating residual stress due to cold bending
I am in the process of designing a sheetmetal structure assembled of plates that are attached to each other by cold bent flanges, all 90 degrees. The flanges of adjacent plates are bolted together.
The structure will be loaded quite heavily by transient events, which are however not cyclic. It is easily verified that the plate webs are strong enough, but near the cold bent areas bend stresses become important. Residual stresses due to the cold bending process are added to these bend stresses. They become the center of attention when fatigue is taken into consideration.
So that is why I am interested in estimating the residual stresses due to the cold bending process. I am aware of the qualitative theoretical model which helps to form an image of the way these stresses arise but is not very helpfull in determining actual residual stress levels. I do not know how these stresses are estimated in real life situations. We do not have the means to perform experiments on already formed plates.
Thanks! Mark
RE: estimating residual stress due to cold bending
Many design codes for applications with high fatigue, or other causes of fracture typically require heat treatment or notch toughness testing of the plate material. Other design codes where stability or plastic failure modes govern have conservative methods to discount and ignore these residual stresses. Which group does your project fit in?
Wadavis
E.I.T.
RE: estimating residual stress due to cold bending