A few questions about a problem involving Trusses

[noobiest09]

Hi! I'm really having a problem understanding this part of statics so please help!

In this picture, http://i312.photobucket.com/albums/ll323/IAmMaxwellEdison/Members.jpg, what are the zero force members and how do I identify them?

I'm pretty sure that GH, CF, and CD are zero-force members. However, I'm uncertain if EH is a zero force member because load is being applied on point E. Also, are AB and AD zero-force members? because there is the reaction force from the pins so I'm not very sure.

Also, is it safe to say that FE is automatically 100N?

I'm sorry for asking so many questions, but I'm pretty sure I will be able to understand the concept much easier if these questions were answered. Thanks!

 

[jbsteele]

Zero force members are members of a truss structure which do not carry any load or experience a force due to the applied loads on other members. GH, CF, and CD can be identified as zero-force members because there is no load being applied on them and they do not experience a force due to other members. AB and AD are also zero-force members because the reaction forces from the pins do not cause them to experience a force, although this may not be immediately obvious. FE is not automatically 100N. The magnitude of the force on FE will depend on the magnitude of the other external loads, such as the 100N load on point E.

 

[kerimek]

Dear student,

Thank you for reaching out for help with your statics problem. Trusses can be a tricky concept to understand, but with some guidance, you will be able to identify the zero-force members and understand the applied loads.

First, let's define what a zero-force member is. A zero-force member is a structural element within a truss that does not experience any forces due to the external loads applied to the truss. In other words, the member does not contribute to the overall strength or stability of the truss and can be removed without affecting its structural integrity.

Now, looking at the given picture, you are correct in identifying GH, CF, and CD as zero-force members. These members are not connected to any external loads and only serve to connect the other members together. EH, on the other hand, is not a zero-force member. As you mentioned, there is a load applied at point E, so the member will experience a force.

Regarding AB and AD, they are not zero-force members either. While there may be reaction forces at the pins, these members are still a part of the truss and contribute to its overall strength.

As for FE, it is not automatically 100N. The value of the force depends on the external loads applied to the truss and the geometry of the truss itself. It cannot be determined without more information.

I hope this helps clarify your understanding of zero-force members in trusses. Remember, a zero-force member does not experience any forces due to external loads, and it is important to carefully consider the applied loads and the geometry of the truss when identifying them. Keep practicing and asking questions, and you will soon have a better grasp on the concept. Best of luck with your studies!