[FEM-problem] Defining max. allowable load

[Stevie G]

Hello to all!
I have this one and only obligatory FEM-course and tbh I'm having some hard time with it,
so I'm hoping that someone can help me out with this assignment.

Homework Statement

Define maximum allowed distributed load p when the own weight of the frame is taken into account. (Own weight is NOT included in p).
Use beam-elements of 2-dof.

(this must be solved with pen and paper so using e.g. Ansys isn't an option here)

http://oi49.tinypic.com/2r3yv4z.jpg

Homework Equations

KQ = F
K= global stiffness matrix
Q= displacement matrix
F= load matrix

The Attempt at a Solution

I have a feeling that first step would be to obtain the global stiffness matrix K.
Then, knowing the yield strength and max. allowable stress we are able to obtain the displacement matrix Q. (Are we?)

And then solve the load matrix F with KQ = F ?

Thanks in advance!

 

[KataKoniK]

Hello there,

It sounds like you are on the right track with your approach. First, you will need to obtain the global stiffness matrix K for the frame. This can be done by using the stiffness matrices for each individual element and assembling them together to form the global stiffness matrix. You can find these stiffness matrices in your course materials or by doing some research online.

Next, you will need to consider the yield strength and maximum allowable stress for the frame material. This will help you determine the maximum displacement that the frame can withstand without failing. From there, you can calculate the displacement matrix Q using the global stiffness matrix and the maximum displacement value.

Finally, you can solve for the load matrix F by using the equation KQ = F. This will give you the maximum allowed distributed load p that the frame can withstand without failing.

I hope this helps and good luck with your assignment! If you have any further questions, don't hesitate to ask.