The discussion focuses on the equilibrium equation for frame member BE in a structural analysis context. Participants clarify that the force P (210 N) is not included in the free body diagram (FBD) of member BE because it acts on the pin, which exerts an internal force Ex on member BE. The solution assumes that the moment at the pin is zero, allowing for a simplified moment balance. The internal cut in the FBD is made infinitesimally away from the joint, thus excluding external forces like P and only considering internal forces such as Ex, Ey, and the vertical reaction from the roller.
PREREQUISITESStructural engineers, civil engineering students, and anyone involved in analyzing frame structures and equilibrium conditions in mechanics.
The problem statement seems to imply that the force is acting on the pin. The pin is then assumed to exert a force Ex on member BE. In the problem solution, moments are taken about the pin, so the force at E doesn't matter in this moment balance. However, the solution implicitly assumes that the moment at the pin is zero (i.e., BE rotates freely at the pin).princejan7 said:Homework Statement
http://postimg.org/image/scm11r483/
So when considering the free body diagram for member BE, why is the force P not included?
Does the Ex account for the bit of the P=210 that would act on member BE?
Did you solve for Ex? It's quite a bit of P.princejan7 said:Does the Ex account for the bit of the P=210 that would act on member BE?