This question primarily involves finding the direction of forces in a truss.
Let's give a scenario in Method of Joints
One source I found says that in finding the direction of the source, it would be beneficial to assume everything is tension, if one attains a negative value, the force would simply be in compression.
However, wouldn't this be inaccurate in resolving forces using equilibrium equations (summation of forces along x =0 ; summation of forces along y=0) as they are sign-sensitive?
For example, a truss with several members are given. For the first member, it is assumed that everything is tension; however, it is found that one internal force is compression. With Newton's third law, the adjacent joint will also experience an internal force that is in compression, should I change its direction? Would that not affect summation of forces along x=0 and summation of forces y=0 as mentioned?
Please enlighten me, thank you