1. Find displacements at each node and forces in each element for the series of spring…

1. Find displacements at each node and forces in each element for the series of spring shown below. (20 points) 3 4 3 100 K k1 k4 u2 k3 из U4 k1 50 k/in k2- 20 k/in k3-40 k/in k4-50 k/in 2. For the following truss structure, all the members has the same elastic modulus E and cross section area A. (10 points) 2 4000 lb 10.000 lb 3 3 4 30 in. 30 in. 30 in Find the structural stiffness matrix [K] Write down the equation for calculating the unknown displacements, also indicate the DOFs of the unknown displacements such as U2. (No need to solve answers) Write down the equations for solving unknown forces, also indicate the DOFs of the solved reaction forces such as Fı. (No need to solve answers) 1. 2. 3.