Answer Happy

That's all. It's from last year's Final for the finite element
class
3. (40 points) Let us consider the Limit Design of the 4-bar elastic-perfectly plastic truss shown below. Assume that all the given numeric problem data are in consistent units. E, A same for all elements 1.0 m 12 0.5 m 3 0.5 m 0.3 m 0.7 m We need to obtain an optimum design a* = (a*, a, a, a) for this truss that maximizes the limit load factor a such that the stresses in members are within allowable limits, and that the total volume does not exceed a given value. The nominal forces acting on node 2, of magnitude 12 and 8 respectively, are shown in the figure. The allowable yield stress limits in tension and compression are +9 and -9, respectively, for each of the bars, and the bound on the total volume V is 250. 1. State a formal design optimization problem that, when solved, will provide the optimum de- sign that we seek. 2. Recall that optimization problem: minimize obj = ctx such that A.Xsb Aeq. X = beq lb < x <ub can be solved by the MATLAB linprog( command as follows: [x_opt, obj_opt]=linprog(C,A,b, Aeq, beq, lb, ub) Write a complete MATLAB script that will compute the optimum limit design for the given 3-bar truss.