Wednesday, August 19, 2009

Disk Stress Analysis for Centrifugal Fans

I have been developing some formulas for calculating the stress in disks due to centrifugal force. These are useful to have when designing an industrial fan to ensure that the hub stresses and strains are acceptable. If the hub stresses are too high, the hub may crack at the keyway. If the hub radial strain is too high, the hub may come loose from the shaft as the strain exceeds the interference fit.

I combined formulas used for stress & strain due to centrifugal loading with the formulas for the pressure from an interference fit along with the formulas for radial strain due to pressure. The resulting formulas showed very good correlation with FEA results conducted in SolidWorks/CosmosWorks. The full paper describing the formulas along with an Excel spreadsheet containing the formulas, and Solidworks models can be purchased for providing training in developing analyticial and FEA methods for stress analysis of fans. Further details about fan engineering can be found at the Mechanical Design section of my website.

Making Stairs with Landing Revit

 This is a really good video, super simple for making stairs in revit with a landing: