Question

In Finite Element Analysis (FEA) What is a local stiffness matrix and a global stiffness matrix?

Answer 1

The local and global stiffness matrix related with co ordinate system

In fem when a body is divided into elements then each element has own co ordinate system known as local co ordinate system and the stiffness matrix correspond to local co ordinate system known as local stiffness matrix

When all elements are assembled with respect to whole body co ordinate system known as global co ordinate system and the assembled matrix with to global co ordinate system known as global stiffness matrix

Element stiffness matrix = k1 ,k2,k3.......

Assembled global matrix = [ K ]

Then

{U}= [K]{F}

Here {U} = displacement vector

[K] = global stiffness matrix

{F} = global load vector