Discussion Overview
The discussion revolves around determining the force applied to mounting holes in an aluminum plate when a torque is applied to a component attached to it. The focus is on the calculations necessary to ensure the plate's thickness is adequate for the expected loads, involving concepts of bearing stress and shear tear out stress.
Discussion Character
- Technical explanation
- Mathematical reasoning
- Homework-related
Main Points Raised
- One participant inquires about calculating the force on four mounting holes due to a torque of 35 Ib.in applied to a shaft connected to a component mounted on a 0.1" thick aluminum plate.
- Another participant suggests that if the screw holes are symmetrically arranged, the force on each hole can be calculated as Torque / (r*4 holes), but notes that this assumes equal distribution of forces, which may not be accurate. They propose that a more reasonable approach is to assume only 2 screws react to the torque, leading to Force = Torque / (r*2 holes).
- A participant mentions that once the force is determined, the adequacy of the plate thickness can be assessed by calculating bearing stress and shear tear out stress, offering assistance for these calculations.
- Another participant reiterates the method for calculating bearing stress and shear tear out stress, providing formulas for each and suggesting limiting the stresses to 40% of the yield strength of the plate.
Areas of Agreement / Disagreement
Participants express varying assumptions about the distribution of forces among the screws, with some suggesting equal distribution and others proposing that only a subset of screws may react to the torque. The discussion remains unresolved regarding the exact method for calculating the forces and stresses involved.
Contextual Notes
Participants mention the importance of the arrangement of the screw holes and their distance from the edges of the plate, which may affect the calculations. There is also a reference to typical yield strength limits for the material, but specific values are not provided.