Answer Happy

Q2. Statically determinate or indeterminate truss analysis by the stiffness method (70 marks) a) Determine the stiffness matrix of the whole truss shown in Fig. 2 in the global co- ordinate system. Indicate the degrees-of freedom in all the stiffness matrices. Assume for each member AE = constant. (15 marks) b) Determine the stiffness matrices of elements 2, 3 and 4 in the local co-ordinate system and then convert the local stiffness matrices to the global co-ordinate system. Show all calculations. Check the results with those obtained in part a) above and comment. (15 marks) 1 c) Calculate all the nodal displacements and all the member forces of the truss. (25 marks) d) Repeat the problem using the Strand7 finite element software package. Show the truss model with loadings and boundary conditions. Display the deflected shape of the truss. Submit a hard copy from Strand7 showing the nodal displacements and member forces (highlight these in the hard copy). (10 marks) e) Present a table showing the comparisons of member forces from the stiffness method (manual calculations) and Strand7 analysis. Compare the maximum vertical deflection of the truss based on the stiffness method and Strand7 analysis. Comment on the comparisons of the values between the two. (5 marks) 2 m 2 kN 2 m