The discussion revolves around the issue of flange screw failures in a vehicle, specifically focusing on the potential role of vibrations in causing these failures. Participants explore methods for measuring flange acceleration and assessing whether the observed acceleration levels are excessive. The conversation includes technical considerations related to bolt specifications and structural analysis.
Participants present various approaches and considerations regarding the measurement and analysis of vibrations and screw failures, but no consensus is reached on the best method or solution. Multiple competing views remain regarding the technical aspects and potential remedies.
Limitations include the need for specific technical data that has not yet been provided, as well as unresolved questions about the adequacy of current measurements and analyses.
Hi--from the acceleration signal you should be able to reconstrunct the loal diplacement as function of time. Then, you could do some FEM calculations on the structure, maybe checking for fatigue failure.serbring said:Hi guys, in my company we have seen a lot a failures on a flange, in particular one flange screw strips. This flange is mounted in a vehicle and it support some hydraulic pipes. The designer thinks vibrations should cause the failure and so he suggests me to measure the flange acceleration along the screw axis. But how can I understand if the acceleration are too high?
nvn said:serbring: Is this a tapped hole? Post all dimensions, thread size, thread engagement length, material specifications, bolt installation torque, lubrication, and applied loads. Has the tapped hole been measured, to ensure the fabricator is not tapping the hole with sloppy thread tolerance, exceeding the thread tolerance specified on the drawing? Perform a bolt stress analysis, to determine if the thread shear stress exceeds the proof stress. Perhaps try a bolt with a polymeric locking patch.
drMS said:Hi--from the acceleration signal you should be able to reconstrunct the loal diplacement as function of time. Then, you could do some FEM calculations on the structure, maybe checking for fatigue failure.
M