Bridge truss Static Equilibrium

AI Thread Summary
The discussion revolves around calculating the forces of tension or compression in a bridge truss structure, specifically focusing on components T_AC and T_CE. The problem involves a bridge truss spanning 214 meters with a car weighing 1270 kg at the center, and the structure is designed to allow horizontal sliding for thermal expansion. Participants suggest using Lami's Theorem and the method of joints to determine the forces in the truss members. It is clarified that T_AC can be calculated as the horizontal component of the force in member AB, leading to the conclusion that T_AC equals T_AB multiplied by the cosine of 35 degrees. The discussion emphasizes the application of static equilibrium principles in structural analysis.
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Homework Statement


A bridge truss extends x = 214 m across a river (Fig. P12.68) where θ = 35°. The structure is free to slide horizontally to permit thermal expansion. The structural components are connected by pin joints, and the masses of the bars are small compared with the mass of a 1270 kg car at the center. Calculate the force of tension or compression in each structural component.

Homework Equations


Lami's Theorem
A/sin a = B/sin b = C/sin c

The Attempt at a Solution


I found the forces in most of the members except T_AC and T_CE.
How do i find the force? Should I use moment equation? Is so how should I apply it?
 

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If you have correctly solved for the force in AB, then T_AC is just the horizontal component of the force in AB. Use the method of joints.

Welcome to PF!:smile:
 
PhanthomJay said:
If you have correctly solved for the force in AB, then T_AC is just the horizontal component of the force in AB. Use the method of joints.

Welcome to PF!:smile:

Thanks a lot.. I got it right now.. T_AC = T_AB cos 35
 
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