problem with story shear

[saharnaz]

hi.
my model is a 2D moment frame with BRB. i'm doing time history analysis now i want to catch story shears.i know that the story shear in the first story equals to the base shear and( i have the base shear) and also i know that for calculating the story shear i should take element recorder and then sum the forces (fx in the global coordinate)in all elements in that story, but when i do this in the first story :sum of the element forces>>>>base shear, why??

[fmk]

check your math .. the reactions at the nodes are simply calculated by all bode adding up applied loads and then subtracting for each element the unbalanced forces .. you want to recore element globalForces (not local)