Use the stiffness method to determine the following: - Stiffness matrix for each member - Global stiffness for the entire structure 15-1. Determine the moments at D and 3. Assume 2 is a roller and and 3 are fixed. El is constant. 15-2. Determine the moments at D and 3 if the support 2 moves upward 5 mm. Assume 2 is a roller and and 3 are fixed. EI = 60(106) N. m. 1 25 kN/m 6 m- Probs. 15-1/15-2 N 4 m 6