Advanced Structural Stiffness - Numerical Structural Analysis - page 228

Table 5.11. Example 5.3 Member stiffness

P L Final P D G

0.06 − 18.56 − 18.56 kips ∆ x2

− 2.26 0.45 9.45 kips ∆ y2

0.00 − 151.73 64.27 kip-in q z2

0.08 18.56 18.56 kips ∆ x1

− 2.45 ∆ y1 − 0.45

8.55 kips

0.00

q z1

216.00 0.00 kip-in

Table 5.12. Example 5.3 Member stiffness

P L Final P

D G

0.08 20.19 20.19 kips

∆ x1

− 2.45 − 3.18 − 3.18 kips

∆ y1

0.00 0.00 0.00 kip-in

q z1

− 0.04 − 20.19 − 20.19 kips

∆ x3

− 2.25 3.18 3.18 kips

∆ y3

0.00 − 550.21 − 550.21 kip-in

q z3

Table 5.13. Example 5.3 Member stiffness

P L Final P D G

− 0.04 7.58 7.58 kips ∆ x3

− 2.25 − 32.84 − 32.84 kips ∆ y3

0.00 − 1772.68 − 1772.68 kip-in q z3

0.06 − 7.58 − 7.58 kips ∆ x2

− 2.26 32.84 32.84 kips ∆ y2

0.00 − 1379.89 − 1379.89 kip-in q z2

For member 4, the deformations at joints 4 and 2 are used. Since this
member had a load, the fixed-end forces and moments must be added to
the results. Table 5.14 contains the final member end forces in the local
system along with global deformations used to find those end forces.
For member 5, the deformations at joints 5 and 3 are used. Table 5.15
contains the final member end forces in the local system along with global
deformations used to find those end forces.
Releases can also occur for the axial and torsional components of the
member stiffness. If either end of the member is released for ∆ x or q x , then
all the corresponding stiffness components are zero. If both ends of the