geometric stifness
geometric stifness
(OP)
please i want calculate the total displacement so i divide the total load on a small load increment how can i do this .thanks
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RE: geometric stifness
RE: geometric stifness
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: geometric stifness
Second... I don't understand how it is related to your problem description!
RE: geometric stifness
RE: geometric stifness
My problem is that the behavior of the structure is not linear so equation F(forces)=K(stiffness).D(displacement): is applicable just for a small load increment so the equation become dF=k.dD to resolve this equation i know that i need to use numerical method's in my case want use secant stiffness method's to resolve system
thanks
RE: geometric stifness
RE: geometric stifness
If you're looking for an approximate hand calculation, then use either the B1-B2 method described in AISC, or the Theta method described in ASCE-7.
The theta method is the one I usually use:
Secondary Moment = P*Delta_0
where P = axial force in the frame and Delta is the 1st order deflection of the frame.
Apply this moment to your structure using a secondary shear
Secondary shear = P*Delta_0 / H
where H is the height of the frame.
Theta is the ratio of the secondary sehar to the origial story shear, Vo.
Theta = P*Delta_o / (H*Vo)
Your incremental deflection will then be Delta_o*Theta. This additional deflection would result in additional P-Delta mometn. The limit of the infinite series becomes:
Delta_total = Delta_o / (1-Theta)
RE: geometric stifness
Regards
Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis
http://www.engissol.com/cross-section-analysis-des...
RE: geometric stifness
regards
chris magadia
www.chrismagadia.com
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