1. (20 pts) An aluminum column (E = 72GPa) that is 8 m long with the rectangular hollow cross- section shown below is fixed at one end in all directions. On the other end, it is pinned in the weak axis and free in the strong axis. The dimensions are given as: h = 5 cm, b = 10 cm and the thickness of each side is 1 cm. Using ASIC factors: (a) Determine the critical buckling load for the column (b) Without changing the column length, boundary conditions or material, how could you make the critical loads equal? b Figure 1: Hollow Rectangular Beam Cross Section h