hi,
is there somebody who has the building codes in brasil
(wind loads an so on) in english version or is able to
do structural engineering in brasil ?
first of all we have to satisfy the rule of equilibrium
between inner and outer forces. so if we calculate Mpl, the
sum of horizontal forces Npl of the parts above and below
the plastic center line have to add up to zero.
(pure bending assumed)
if you assume the plastic centerline anywhere...
hi agps,
first of all: to calculate Wpl you have to know Mpl.
the plastic center line (where the tension changes to compression) divides the area of the whole cross-section
in two halfes, because of equilibrium...
that means that it is located near or in
the lower flange.
hi,
there is a easy approximation approach:
take the flange an 1/5 of the web as a cross section and calculate the buckling value for that. thats all !
so you are on the save side
i think we should differentiate between global and local
instabilities. global lateral tors. buckl. may be avoided by the deck itself and local buckling may be avoided by
maintaining the form of the cross-section for example by
local stiffeners. this is proven by experiments.
i think it is...
this problem of lateral torsional buckling may be solved
by proofing that the rotational stiffness of the deck is
higher than the required rotational stiffness to
avoid lateral torional buckling.
the result will be that you need no bracing.
hi,
do you speak of steel structures ?
if the load is increased,
plastic hinges may occur at the most stressed area for example at the middle supports of an continuous beam.
further increases are possible because in midspan the
plastic moment is not yet reached.
if there is also a plastic...