Consider the plane structure shown in Figure P5-39. First assume the structure to be a plane frame with rigid joints, and analyze using a frame element. Then assume the structure to be pin-jointed and analyze as a plane truss, using a truss element. If the structure is actually a truss, is it appropriate to model it as a rigid frame?

How can you model the truss using the frame (or beam) element? In other words, what idealization could you make in your model to use the beam element to approximate a truss?

4 m 8. 10 kN 3 m 6. 20 kN E = 200 GPa A = 2 x 10* m? 1 = 4 x 10-4 m* 3 m 20 kN 3 O 3 m 3.