Instability problems due to dynamic loading

For static loads Equations 1 and 2 are held true as obtained from the paper «Instability ProblemsInvestigation of Pcritical joint load under axial loads» (Karatzas 2009).

P c

h =

⋅

⋅

1 ψ ψsin( )

(1)

and for very small angles ψ the following equation holds:

P c hcritical loadjoint

= 1

(2)

where c1 = natural spring rotational constant and h = height of the member.