1. Derive the global stiffness matrix for the following two-spring system k.
2. a. Obtain the global stiffness matrix [K] of the assemblage shown in Figure 1 by superimposing the stiffness matrices of the individual springs. Here k1, k2, and k3 are the stiffnesses of the springs as shown.
b. If nodes 1 and 2 are fixed and a force P acts on node 4 in the positive x direction, find an expression for the displacements of nodes 3 and 4.
c. Determine the reaction forces at nodes 1 and 2.
3. For the spring assemblages shown in Figure 2, determine the nodal displacements, the forces in each element, and the reactions. Use the direct stiffness method.
k = 50 lb/in
k = 100 lb/in
k = 50 lb/in