Question

Rigid member DB is pinned to rigid member ABD at joint B. Length a = 3 ft, length b = 4ft, and length c = 3 ft. Force F = 200 lb is acting to the right at A. Determine the magnitude of the compression force (in lb) acting in member BD. А с B

Answer 1

truss Sa We need to notify that DB is element (two force mersber) ABC ist consider the free body diagram of a=3 ft A F = 200 eb b = 4 ft c=3ft 28 B F=qoulbo EBD 4ft 드 ca fey a=3.ft BDC seperately for clear under taking hing sino=3 5 -standi coso=4 B FOD sino 5 5ft a FBD 4 st سے 2 ft FBD coso BD=J =J4²+ 25ft. Taking moment about c, I Mc=0 79006 + fod Goo (0) + Fsofino C4ft) =0 FBD x 3 x 4 1800

FBD 1200 x 5 FBD = 500 lb Now take FED of BD. FBO B D Da Dy The compression force in BD is, FeD = 5000
the member BD is a two force member and compression force in BD is 500N only