How can we calculate the combined stiffness of a spline connected to a straight member?

I have a geometry that looks something like this. What will be the combined stiffness of the members?

• Which stiffness? Axial? Bending? The full stiffness matrix? Considering p-\delta effects or in the linear regime? Oct 30, 2023 at 19:31
• This is basically a slice from cochlea, where the bending part(material 2) is basilar membrane and the material 1, is a bridge tissue. both of them bend but their individual stiffness is different. For our model we are assuming them to be isotropic. I am primarily interested in the bending stiffness. Oct 31, 2023 at 3:30
• I get that the materials are different, but what are your expected loads? Are they point loads or distributed loads? What's the loading direction? Are you expecting large deformations? Oct 31, 2023 at 16:55
• Load is distributed and given by p = p0*sin(wt) and acting along the length of the slice i.e. from the bottom in the current view. Nov 6, 2023 at 18:04

Each part stiffness is the $$EI$$ of that part.

However, calculating the deflection under a certain load analytically by hand could be a term project.

Edit

I searched for assembling the global stiffness matrix from member local stiffness matrices. Here is a couple of answers.

global 2