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Download Problem Set 3 for Elementary Structure I | CEE 379 and more Assignments Civil Engineering in PDF only on Docsity!
3 Fak Ewer ; CEE 379 Froblem Set 3 Winter 2007 6 lon (Due Friday, Oct. 19, in class or 4:30 PM in 233 More) Problem 1, Consider the truss shown below. ° 25k 50k 40k a) For this truss, determine: degree of external static indeterminacy # of unknown member forces and reactions # of independent eqns of joint equilibrium, zZ degree of internal static indeterminacy degree of kinematic indeterminacy b) Compute the reactions at A and G, and show these on a neat drawing of the truss. ZF On the same drawing, identify all of the zero-force members. c) Draw a free-body diagram of part of the structure that will enable you to determine the axial forces in members HI, HL and DE. For each member, A $ compute its axjal force(tension or compression) using a single equation of equilibrium. dy Using the information from b) and c), as well as additional equations of 6 equilibrium, determine the axial forces in all of the members of the truss. Show all of these member forces on a neat drawing of the truss. °) Assume that all of the members are to be made with steel that has a maximum allowable stress of 24 ksi (compression or tension), and all of the members are to 2 have the same cross-sectional area ¢ What is the minimum cross-sectional area of steel required for the members? * Assuming that the unit weight is 490 Ibs/ft*3, what is the total weight of the resulting truss? — * How does this weight compare with the applied loads? (*) 
