Question

Problem 1: A lateral load resisting system of a 4-story building consists a K-truss and is shown in the figure below. Based on the ASCE 7-10, the wind load at each floor level was calculated and applied to the truss joints as shown in Figure below. 1. Determine if the truss system is determinate and Stable (support A is pin; and support B is roller) 2. Calculate the support reactions 3. Using any analysis method, calculate the forces in members FJ. HJ and HK of the following truss under applied loading. Indicate if the forces are tension or compression. Note: you can use a section cut going through FI, IJ, KJ and HK. -9ft 9 ft 25 k- N 12 ft 50 k- 12 ft G F 50 k H 12 ft D E 50 i 12f Problem #2: for the structure shown in the figure (support reactions due to applied loading are provided), calculate the internal forces at point D M 30.4k-ft ask 12 4fh (point D is at 4 ft. from point C) and at Point E (point E is at 6 ft. from support A). Points D and E are not shown in Figure. R 1.6k AX 8n 02k/ RAY 2.8

Answer 1

= tan 3.13 50 K 50 k H 50k Dgu of static inddtirminauy : m no.of membeIs Suppdt reations no no jcmt 14 = 28- 28 = 0. 25 3- Statically detirminati ard stable CVfually) Taking moment about n: 25x4 8 - R,x 18- 50x 36 50 X 12 + 50 x 24 Upe ard 266. 67 k RB L9-99 downuard - Ho 5b t 50 + 50+d50 MN, NK, LI Zero ce members ave

Ciii) At EH- 0 25k M Compussive At jont N/: N At omt M: PLM PLM PTM CAAC53.13) /PIM Cose PIM41.66 k Tensile . Compressive Pk=4.66 k At jint PKM HI-66 OPEN 41.66xCoA- PIK Tensile Complussive PAK = 33.3 k joimt At PIM-41.66 Tensile 33.3 k P FI = HI.66 cOM- FIg = 0 YPI Compressive J5k

At omt J PTH EH 0 x cas0 =50 Tensile PEI = 4. 66 k PT4.66 k, Tensile 41C6 k, Comp a SSive PHK33.3 kCompe ssive 2 0.8k 30kt 0.8k 0.k/4t D 64t 44 print 0.8k E : 30. 4 I.6 M 44 Compressive FBD Lett potio. Fue body diagram 8-0.8 Dy- 0 Shear tole -304t °8x 6 - 0. 8x2 +DM-0 k- FE Bending moment DM =

At pomt B 30.4 BM 4tt 4 4t 2.8-0.8-0. 8 -1.2 + By -O EH O k 30.4-8x2- 0-8 x 8 - o. 8x4+ BM= O I2.8 k-t point At D : PM >D o.8 k 4 M0(4 x0-2)x- DM.6 k-4t