{"id":308277,"date":"2023-09-25T06:58:16","date_gmt":"2023-09-25T06:58:16","guid":{"rendered":"\/forum\/forums\/topic\/no-convergence-due-to-screw-preload\/"},"modified":"2023-09-25T06:58:16","modified_gmt":"2023-09-25T06:58:16","slug":"no-convergence-due-to-screw-preload","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/no-convergence-due-to-screw-preload\/","title":{"rendered":"no convergence due to screw preload"},"content":{"rendered":"
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Hello,<\/p>\n

I want to analyze an aluminum casting housing for my thesis that is subjected to internal pressure. The assembly consists of seven components, all connected through a cylindrical surface and an end face. All fasteners are designed as blind holes, so there are no nuts involved.<\/p>\n

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The geometry was created in Inventor and imported into Ansys as a STEP file. The cast parts are connected to each other through cylindrical and end surfaces and defined as frictional. The screws are simplified as cylinders (screw head, shaft, and thread). The threaded surface is connected to the housing as a bonded contact, and the screw head surface is also bonded to the casting part. The housing is fixed using a cylindrical support and a rigid support at the attachment points.<\/p>\n

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I applied the preload force on the shaft, without any contacts or constraints on the surface. When I apply pressure to the inside of the housing, I obtain a solution. However, when I add the preload to the screws, the calculation stops at 17% and restarts. Ansys aborts the calculation after about 45 minutes. It doesn’t make a difference whether I apply the preload in one load step or two load steps (first step: preload, second step: pressure with preload locked).<\/p>\n

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Thank you!<\/span><\/span><\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n

 <\/p>\n","protected":false},"template":"","class_list":["post-308277","topic","type-topic","status-closed","hentry","topic-tag-bolt-pretension","topic-tag-convergence"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t