Understanding the concepts on Degrees of Freedom
given that :- Different mode shaope values for different Time periods
Need to find:-Mn,LN,`Gamman`,Mn*,Base shear
`phi1=[[``0.334],[0.641],[0.895],[1.078],[1.173]]`
`M1=phi nTm Q`
`=[[0334,0.641,0.895,1.078,1.173]]*m[[0.034],[0.641],[0.895],[1.078],[1.173]]`
`=[154459/4000]m`
M1=3.8641m
similarly
WE KNOW THAT:-m
Five storeys of building:-
| Mode | M values |
| Mode 1 | M2=3.85 |
|
mode 2 |
M3=3.8613 |
| mode 3 | M4=3.8611 |
| mode 4 | M5=3.8612 |
Now we need to calculate Ln
`Ln=phi nTmL`
`L1=[[0.334,0.641,0.895,1.078,1.173]]*m[[1],[1],[1],[1],[1]]`
L1=4121/1000
l1=4.121
similarly
L2=-1.29
L3=0.68
L4=0.381
L5=0.175
NOW WE NEED TO CALCULATE Mn
```Mnast=(Ln^2/ M^n)`
M1=(4.121^2/3.8614)
M1=4.398
similarly
M*2=0.432
M*3=0.119
M*4=0.0357
`M*5=0.0079`
`Gamman=Ln/M^n`
`Gamma1=L^1/M^1`
=L1/M1=4.121/3.8614
`Gamma1=1.067`
SIMILARLY
`Gamma2=-0.336`
`Gamma3=0.1761`
`Gamma4=0.0986`
`Gamma5=0.045`
`OW WE NEED TO FIND THE BASE SHEAR Vbn=Ln^2* An/Mn`
we know that Pseudo Acceleration,An value from the graph
for mode 1 force vector `f1=(m1)(phi1)(Gamma1)(A1)`
`f1=m[[0.334],[0.641],[0.895],[1.078],[1.173]]*1.067*0.27`
`[[0.096],[0.187],[0.257],[0.3105],[0.335]]`
there fore Vb1=1.121
similarly
Vb2=0.31
Vb3=0.121
Vb4=0.035
Vb5=0.001