8.14 through 8.17 Determine the joint displacements, mem- ber local end forces, and support reactions for the space frames shown in Figs. 8.14 through 8.17, using the matrix stiffness method. Check

the hand-calculated results by using the com- puter program which can be downloaded from the publisher's website for this book, or by using any other general purpose structural analysis program available./nZ 15 ft Z Material properties are constant: E = 10,000 ksi 1₂ = 1,= 18.7 in.4 J = 37.4 in.4 Fig. P8.15 6 m G = 4,000 ksi All members have circular cross-sections with A = 4.52 in.² 6 m 30 KN 150 k-ft Y 20 ft 15 m 2₂ 10 kN/m 150 k-ft 25 ft 5 kN/m L=260(106) mm4 1,= 86(106) mm² J=4.510 mm X 12 m Material and cross-sectional properties are constant: E-200 GPa G=76 GPa A = 19,000 mm² X Fig. P8.17 2 k/ft 2 k/ft 30 ft 2 k/ft 2 k/ft 40 k Member orientations: Girders: local y axis is vertical Columns: x Material and cross-sectional properties are constant: E = 29,000 ksi G = 11,500 ksi A = 47.7 in.² 1. = 5,170 in.4 1,=443 in.4 J = 18.5 in.4 40 k 30 ft 30 ft