Step load in a transient with ANSYS

[zaronline]

Hi to everyone!!!
I'm new on this forum..i have a problem..i cannot understand if the way in which i model a stepping load on a structure is correct. I have a load given for a time equal to 10**-6, then it comes to zero.
here there is the code:


freq=201250
mp,damp,1,(2*0.02/(2*3.14*freq))
/solu
outres,all,all
antype,trans
trnopt,full
timint,off
deltim,((1/freq)/100)

!central node, 8 elemnts
nodo_centr=61

!central node,16 elements
!nodo_centr=181



time,10**(-6)

nsel,s,loc,x,(b+a/2)
nsel,r,loc,z,(a-c)/2
f,nodo_centr,fy,0
nsel,all

lswrite

!two possible values of starting point of the step, choose one



time,100*10**(-6)
timint,on


kbc,1

nsel,s,loc,x,(b+a/2)
nsel,r,loc,z,(a-c)/2
f,nodo_centr,fy,-0.1e6*a*a
nsel,all
lswrite



time,150*10**(-6)
kbc,1
nsel,s,loc,x,(b+a/2)
nsel,r,loc,z,(a-c)/2
f,nodo_centr,fy,0
nsel,all



lswrite
lssolve,1,3
/post26


nsol,2,nodo_centr,u,y
plvar,2

is it correct??
thank you!!!
byee