stability of lightweight structural sandwich panels exposed to fire

Second International Workshop « Structures in Fire » – Christchurch – March 2002
so that
∆= αTL 2
1
8d
(A6)
Annex B
The classical text book equation for the horizontal restraint force H needed to support a
catenary (cable-like structure) of span L carrying a uniformly distributed load w per unit
length having a mid-span deflection D, Figure B1, is simply derived in the following way.
For equilibrium ∑ M = 0 where M = moment. Taking moments about point A for the right
hand half of the catenary,
w LL = Hd + w LL from which
22 24
H
wL 2
=
8D
(B1)
Note that H becomes infinite as D becomes small
L
17100
H
H
2500
D
wL/2
A
4300 L/4
wL/2
wL/2
Figure B1 Catenary force diagram
Load per unit length, w
Annex C
The equation derived below relates the axial shortening ∆ L to the mid-span deflection ∆ N for
a flexible member when the member bows into a circular arc. Consider an initially straight
member AB of length L, Figure C1, in which end A is position fixed. The member is slender
so that the application of an axial compressive force P at end B causes negligible elastic
compressive strain in the material but causes it to bow into a circular arc ACD.
From Figure C1
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