AnsweredAssumed Answered

bolt connectors on sheetmetal parts

Question asked by Mark Scholten on Mar 26, 2014
Latest reply on Apr 1, 2014 by Mark Scholten

Hi everyone,


i am sort of stuck on a project and hoping that someone can get me going again. I am doing a static study of a sheetmetal duct loaded by internal fluid pressures. The loading is such that membrane stresses will be significant. The sheetmetal panel flanges are connected using bolts. I am interested in plate deflections, plate stresses (in the webs and flanges at the bolt holes) and bolt stresses.


So initially I used "no penetration" contact conditions between the panels and bolt connectors, used shell elements created by SW simulation (so did not create them myself), and ran the study using the large displacement option to account for membrane stresses.


As it turns out, the simulation fails (inspite of on the bolt connectors in combination with shell elements (see, i get an error stating that the bolt length to diameter ratio is less than 5 and solids elements should be used.


After reading the post 49609 and KB S-058593 I decided to first try running the study using solid elements. Besides taking a very long time (even though the mesh only has 1 element in the through-thickness direction), it fails in the first load iteration (at 5% load) without stating what the problem is.


What is the smart road to take? Manually creating faces, replacing the bolt connectors and running the study without further changes? I am confused by the remark in

KB S-058593 stating that shell thickness should be SMALL enough to obtain desired accuracy, while the problem seems to be that the bolt length-diameter ratio should be INcreased... Does that mean that creating the shells manually would not remove the problem? Doing a validation study as KB S-058593 suggests is something i would like to avoid as we are pressed for time.


Thanks for your ideas,