Question

NOTE: This is a multi-part question. Once an answer is submitted, you will be unable to return to this part. The Howe bridge truss shown is subjected to the given loading. It is discovered that the material out of which some of the members of the truss are made might not be strong enough to support the forces acting on them. The main members in question are members HD, CD, and GD of the truss. It is desired to determine the force in each of these three members, HD, CD, and GD, so the strength requirements of these three members can be known and compared to the strength capacity of the material out of which these members were constructed. P2 Н G F А B с D x m each section = y m where P1 = 30 kN, P2 = 34 kN, B3 = 26 kN, P4 = 46 kN, x= 12 m, and y= 3 m Now that the truss has been divided into two sections, the left-hand section, section ACHJ, will be used for analysis. Using this section of the truss, determine the force in member HD of the truss. Is this member in tension or compression? (You must provide an answer before moving to the next part.) The force in the member is N. The member is in (Click to select)

Answer 1

cut 30 Section atott 30KN 34KN 26kN 46kN THO F 3m B D ARE 12 m. HA=0 Efx=0 EFy=0 EME=0 RAIRE = 136 KN RAX12 - 30X12 - 3439 - 26x6 - 46X3 = 0 TRA = 80KN I TRE=56KN 0-1 26KN OKN PHG 'PHD →PCD OKN Vertical Balance of section PHD CO845° + 30 + 34 + 26 - 80 = 0 PHD= - 10.12 KN = 14.146N (compression) Negative sign represents here compression