The Finite Element Method for the Analysis of Non-Linear and ...

Element Matrices
where the following notation has been used
M = time independent Mass matrix
t
K, t 0K L , t tK L =
linear strain incremental Stiffness matrices
t
0K NL , t tK NL = nonlinear strain incremental Stiffness matrices
t+∆t
R = vector of externally applied nodal point loads at time t + ∆t
t
F, t 0F, t tF = vector of nodal point forces equivalent to the element stresses
U = vector of increments in nodal point displacements
Institute of Structural Engineering Method of Finite Elements II 11