Section 8.3 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./n498 Chapter 8 Three-Dimensional Framed Structures Y 20 ft 2 Y 2 k/ft 8 3 2 X 2 k/ft 1 11 2 k/ft 111 +40 k 5 150 k-ft 15 ft / / 3 150 k-ft 1 30 ft 1 25 ft 4) 1 2 k/ft 6 40 k - + - 1 7 4 Z 1 Material properties are constant: E = 10,000 ksi G = 4,000 ksi All members have circular cross-sections with A = 4.52 in.2 Iz = Iy =18.7 in.4 J = 37.4 in.4 Fig. P8.15 Y 15 m X / 30 ft 2 3 30 ft Z Member orientations: Girders: local y axis is vertical Columns: x Z y Material and cross-sectional properties are constant: E = 29,000 ksi G = 11,500 ksi A = 47.7 in.2 I2 = 5,170 in.4 I„ = 443 in.4 J = 18.5 in.4 5 kN/m Z y 2 12 m x x 111111 1/11 X 10 kN/m x 30 -> kN y Material and cross-sectional properties are constant: E = 200 GPa G= 76 GPa A = 19,000 mm2 I2=260(106)mm4 Iv=86(106)mm4 J = 4.5(10 ) mmmm 6 m Z Z Fig. P8.17 6 m

Fig: 1

Fig: 2