44.4. For the truss shown in Fig. P-4-4.4, determine the force in BE by the method of joints and then check this result using the method of sections. Hint: To apply the method of sections, first obtain the value of BE by inspection. 130 ANALYSIS OF STRUCTURES Ans. 12' BF = 2500 Ib C 44.5. In the Fink truss shown in Fig. P-4-4.5, the web members BC and EF are perpendicular to the inclined members of their midpoints. If P = 2000 lb, use the method of sections to determine the force in DF DE and CE. 1200 Ib 44.6. Find the maximum value of P that may be applied to the Fink truss of Fig. P-4-4.5 if the maximum loads permitted in members BD, CD, and CE respectively are not to exceed 7000 lb, 3000 lb, or 5000 lb. 12' 9' Ans. P= 2405 lb 2400 lb 1200 lb With this value of P, what will be the actual loads in these members? Figure P-4-4.4 no 600 Ib 1200 Ib 1.200 lb 600 lb 1800 ib -6'- 8' 6' 4' B D 20' A D. G 8' -80 Figure P44,5 Figure P-44.7 44.7. Determine the force in bárs BD, CD, DE, BE, and CH of the truss shown in Fig. P-4-4.7. Hint: After finding DE, consider a FBD of joint D. BD = 878 lb C; CD = 1750 lb C; DE = 2015 lb C; BE = 1050 lb T; CH = 750 lb T 44.8. Find the force in member FG of the triangular Howe truss shown Ans. 800 Ib J600 Ib 30 H 1600 Ib 800 Ib 1200 lb 1200 lb 1200 lb 1200 lb 1200 lb Figure P-44.8 4-4 Method.of Sections 131 in Fig. P-4-4.8. Wind pressure creates the loads which are perpendicular to the inclined members. Hint: First use the method of sections to determine DF and then consider an FBD of joint E. FG = 5600 lbT Ans. 4-4.9. Assume that the group of vertical 1200-lb loads are removed, from the triangular Howe truss of Fig. P-4-4,8, leaving only the wind loads which are perpendicular to the inclined members. Use the method of sections to determine the force in members FH, FG, and EG. Hint: Determine by inspection the forces in the web members of the left side of the truss. 4-4.10. After using the method of sections to find the force in bars BD and CD of the truss shown in Fig. P-4-4.10, find the force in bar AB. Hint: Use geometry to find the slope of.CD. AB = 2477 lb C; BD = 1770 lb C;-CD = 1118 lb T Ans. 1000 Ib 2000 Ib B 1200 Ib 600 Ib E 12' D A G 20 15 16' 16' Figure P-44.10 15 15' 10 4-4.11. For the truss shown in Fig. P-4-4.11, determine each of the forces in bars BD, CD, and CE by means of an equilibrium equation that determines it independently of the others. 400 Ib 200 Ib Figure P-44.11 : 44.12. Use the method of sections to determine independently the force in bars AD, BE, and CE of the truss shown in Fig. P-4-4.12. AD =.1896 Ib C; BE = 361 lb C; CE = 2100 Ib T Ans. D 12 G 600 Ib 800 Ib 400 Ib 4 panels @ 18' = 72' Figure P-4-4.12 4-4.13. The loads on the Parkèr truss shown in Fig. P-4-4.13 (p. 132) are in kips. One kip equals 1000 lb. Determine the forces in members BD, BE, CE, and DE.