I have an aircraft longeron/frame splice with a mix of neat-fit and interference-fit fasteners. Typically, we calculate fastener stiffness for our FE models using the Grumman equations lap joints. However, looking at the theory and the test data the equations are based on, it doesn't look like fit state is accounted for, and no fit state for the test coupons is mentioned.
There's got to be a big difference in stiffness between NF and IFF joints, and I'm sure it'll affect the load distribution across the pattern. Does anyone know what the assumed fit state is for these equations (Huth/Grumman/Boeing/etc)? How have you accounted for fit state when calculating joint stiffness in the past?
Thank you
There's got to be a big difference in stiffness between NF and IFF joints, and I'm sure it'll affect the load distribution across the pattern. Does anyone know what the assumed fit state is for these equations (Huth/Grumman/Boeing/etc)? How have you accounted for fit state when calculating joint stiffness in the past?
Thank you
