Force Diagram Assistance - please

[gordy52]

Hey all.

I have a practice assessment on mechanics and structures.

question 1one was to calculate mathematically using the method of joint principle the magnitude and nature of the forces for all members of each frame. I have completed this part and the answers are acceptable.

But for question two I am asked to construct a force diagram of the same pin jointed frame. I have looked at force diagrams and even asked for assistance for I am still stuck, any assistance would be very much appreciated.

The triangle and answers from Question 1 are attached

Thank You.

 

[TVP45]

I'm confused about your notation. Are - forces tension or compression?

 

[gordy52]

the 40kn and 20kn forces are downward forces and the two 70kn forces are upward if that's what you mean?

 

[TVP45]

No, I meant EJ and JF both have -- in front and I was wondering what that meant. There is no identification of tension or compression and I thought you might be noting it in that manner.