For a more thorough understanding of the Finite Element Method, it is wise to derive the element force displacement with respect to the global coordinate system.
Recall from Page 6-1, (Equation 1) Note to self; make sure these are 4x4, 4x1, 4x1
Note to self: insert diagrams (2) and the matrices for kq=P
=axial displacement of element e at local node =axial force of element e at local node
The overall goal is to derive equation 1 from equation 2(already derived in Meeting 4) We want to find the relationship between:
The relationships can be expressed in the form:
Consider the displacement of local node i, denoted by : Note to self: make sure the i is enclosed by a square
Insert figure 12-3