Always determine the support reactions first. Then start at a joint or joints where there are just 2 unknown member forces, then proceed to the others.bnosam said:Homework Statement
http://oi59.tinypic.com/2h65cm1.jpg[/B]Homework Equations
The Attempt at a Solution
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All triangles: angles A = B = 53.13 degrees, angle C = 73.74 degrees
from cosine law and the 180 degree ruleBut it looks like all of the joints in the bridge have more than 2 forces? Which joint should I start at?
I was going to start at B but it looks like i have the 3000 lb force, then BC, BE and BA forces which would be too many.
The Method of Joints is a technique used in structural analysis to determine the internal forces in each member of a truss, a type of rigid, triangular structure commonly used in architecture and engineering. It involves analyzing the equilibrium of forces at each joint or connection point in the truss.
The Method of Joints works by assuming that all the joints in a truss are in equilibrium, meaning that the forces acting on each joint are balanced. By applying the principles of statics, such as the sum of forces in any direction and the sum of moments around any point being equal to zero, the internal forces in the truss members can be determined.
The Method of Joints is a relatively simple and straightforward technique that can be used to analyze a wide range of truss structures. It also does not require any specialized software or complex calculations, making it accessible to anyone with a basic understanding of statics and mechanics.
The Method of Joints assumes that all the joints in a truss are perfectly pinned and that the members are connected without any friction. In reality, this may not always be the case, which can result in slightly different values for the internal forces in the truss members. Additionally, the Method of Joints is not suitable for analyzing more complex structures, such as frames or beams with varying cross-sections.
The Method of Joints is commonly used in the design and analysis of truss bridges, roofs, and other structures where the forces acting on the members are primarily axial. It is also used in the field of civil engineering for designing and optimizing truss structures in buildings and other infrastructure projects.