Advanced Methods of Structural Analysis

418 11 Matrix Stiffness Method

a

F

EI h

B EA=•

A

EI

C

D

b

q EI h

B EA=•

A

EI

C

D

Fig. P11.7

Ans:.a/MADMDDFh=2; SDF=2I

.b/MAD

5

16

qh^2 ;MDD

3

16

qh^2 ;SD

3

16

qh .compr/

11.8.The portal frame with absolutely rigid cross barBCis subjected to loadF
as shown in Fig. P11.8. Both diagonal tiesACandBDare not connected at point
K. Calculate the horizontal displacementZof the cross-bar. Construct the internal
force diagrams. Calculate the reactions of support and axial forceSin the cross bar.
AssumeA=ID 60 m^2.

F= 10 kN EA=•

EI

l=6m

h=8m

B

A

EI EA

C

D

K

Fig. P11.8

Ans.ZBCD2:308=EI;MADMDD0:108kNm;SACDSBDD8:31kN;
SBCDF=2:

11.9.The portal frame with absolutely rigid cross barBCis subjected to loadF
(Fig. P11.9). Both diagonal tiesACandBDare connected by hinge at pointK.
Calculate the horizontal displacements of the cross-bar and jointK. Construct the
internal force diagrams. Calculate the reactions of support and axial forceSin the
cross bar. AssumeA=ID 60 m^2.

EA=•

l=6m

h=8m

AD

F= 10 kN

EI

B

EI EA

C

K

Fig. P11.9

Ans. ZBCD2:308=EI;ZhorK D1:154=EI;MADMDD0:108kNm;SKCD
SAKD8:31kN