Question

4-The structure represented in the figure consists of the AEC and BDC bars connected by a C-joint. The AEC bar is 8m between nodes.

Under the conditions stated and according to the dimensions of the figure, calculate:

a) The reactions on supports A and B.

b) The forces acting on the AEC and BDC bars.

100N 1309 E 2m B Am

Answer 1

Keep in mind that, forces in AEC and BDC not same force throughout, different forces are there due to joints E and D in between respectively.

1. So forces in members AS, EC, CD AND BD calculated individually.
   Solutions 100 N с FBD: compression (C) T $300 * Tension (T) T E D 2m C I 2007 A B - Bra Ax lay 4m By In above ABD, AEC = 8m 4 L ACB = 30° & AB=4m it means, singo outa 11 4 length of AEC So, Triangle A ABC is right angular triangle, Distance BC = AC cos 30 8cosso = 6.928 m Efx=0 Aine + Bx = 100 6 Efyzo By & Ay 200 =0 =D LE EMA – By X4 - 100x 6.9287200x 5 = 0 -307.2 - By x4 By: 76,8 N (1)
   
   Ay = = 200- 76.8 5123.2 N CM) consider joint A, FAE EF=0 Ax 1600 Ax – FAECOS 60 =0 Ay Ana FAEC0560 & Efy=0 Ay = + FAE singo FAE 142.259_N C compression? I da Ax = 71.129 (-) consider joint B FBD > Ba By EF2 = 0 2x = 0 Efyzo By = FBD 11 76.8N (c) Now, at point a C, capplying lamis theorem, 1OON FEC 270 100 FUD sin Go 5 Goo sin 30 sinato FEC 20 Fcd :, FECE - 200N; Fed = 173.205 N(T) = 2000 (compression) ve sign indicates, direction is opposite to considered.
   
   Answers FAE = 142,259 N(C) O N Ax=71.129 N() Ba 123.2 N (1) By F FEC 200 (C) Ay - Feo 173.205 CT) 76.8N (1) FBD W 76,8 10)