Time History Analysis Of 2D Frame Using MATLAB (El Centro)
Time History Analysis Of 2D Frame Using MATLAB (El Centro)
(OP)
Hi,
Consider a 2D frame like below which excited by el Centro earthquake:

I'm Using Direct Time Integration To obtain response of structure. I verified my program with SAP200 when a Harmonic load applied in node2 and results are the same. but in this case, i.e. base excitation, i have a problem. Consistent Mass Matrix used here and following relation used in order to obtain nodal forces due to base excitation:
{fg}=-[M]*{Ag}*Ug
and We know that:
[M]{A}+[C]{V}+[K]{D}={fg}
in which [M]=Consistent Matrix (6x6 in this case), {Ag} = Influence Vector (6x1) which is zero except for horizontal degrees of freedom, i.e 4 & 7 that equals to 1. in other words {Ag}=[1,0,0,1,0,0].also Ug is a scalar number that equals to earthquake record data at time t. I wonder if this is Right or Wrong? i know somethings wrong with this because i can't get correct results. I really appreciate if you help me.
thanx...
Consider a 2D frame like below which excited by el Centro earthquake:

I'm Using Direct Time Integration To obtain response of structure. I verified my program with SAP200 when a Harmonic load applied in node2 and results are the same. but in this case, i.e. base excitation, i have a problem. Consistent Mass Matrix used here and following relation used in order to obtain nodal forces due to base excitation:
{fg}=-[M]*{Ag}*Ug
and We know that:
[M]{A}+[C]{V}+[K]{D}={fg}
in which [M]=Consistent Matrix (6x6 in this case), {Ag} = Influence Vector (6x1) which is zero except for horizontal degrees of freedom, i.e 4 & 7 that equals to 1. in other words {Ag}=[1,0,0,1,0,0].also Ug is a scalar number that equals to earthquake record data at time t. I wonder if this is Right or Wrong? i know somethings wrong with this because i can't get correct results. I really appreciate if you help me.
thanx...





RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
One quick way to solve this (very crude) is to attach a large mass to your nodes 1 and 2, and then drive that mass with a force equal to "Large mass" * "ground acceleration".
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
RE: Time History Analysis Of 2D Frame Using MATLAB (El Centro)
It might take some finding, but it must be in Opensees somewhere.
http://opensees.berkeley.edu/
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/