Computer_assgnt_2_solution

# Computer_assgnt_2_solution - AE 420 / ME 471 - Second FE...

This preview shows pages 1–6. Sign up to view the full content.

1 AE 420 / ME 471 - Second FE Programming Assignment Finite Element Code for 2-D Static Truss Structures Friday, March 12, 2010 Due on Friday, March 19, 2010 Problem description The assignment consists of 2 steps. Step 1) Code development From the course web site (under Homework), download the (incomplete) Matlab code ‘truss2d_incomplete.m’, the two input subroutines (‘read_node_input_truss.m’ and ‘read_elem_input_truss.m’) and the illustrative input file ‘test_truss.dat’. Then complete the code (the parts to be completed are indicated with “COMPLETE HERE” comment lines). DO NOT modify the two input subroutines. Don’t forget to indicate your name on a comment line at the beginning of the main code. The test problem used to debug your code is concerned with the simple truss structure described in Figure 2. Figure 2 The horizontal segments have the same circular cross-section (0.15 m 2 ) and are made of the same material (E=300,000 N/m 2 , ρ =200 kg/m 3 , α =0.0001/°C, σ y =10,000 N/m 2 ). The diagonal segments have a different cross-section (0.2 m 2 ) and are made of a different material (E=600,000 N/m 2 , ρ =400 kg/m 3 , α =0.0002/°C, σ y =10,000 N/m 2 ). The whole structure is subjected to the effect of two point forces (P=2000 N, Q=800 N), its own weight and a uniform temperature rise of 60°C.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 File ‘test_truss.dat’ Test truss problem 5 7 2 3 1 -1.0 2.0 2 0.0 0.0 3 1.0 2.0 4 2.0 0.0 5 3.0 2.0 2 1 2 2 4 2 1 2 -2000.0 2 1 0.0 2 2 0.0 4 2 0.0 5 1 -800.0 0 0 0.0 0.15 300000.0 200.0 0.0001 60.0 10000.0 0.20 600000.0 400.0 0.0002 60.0 10000.0 1 2 1 2 2 1 1 3 3 2 2 3 4 1 2 4 5 2 3 4 6 2 4 5 7 1 3 5 The undeformed (dashed) and deformed (solid) shapes of the structure are presented in the figures below.
3 -1 -0.5 0 0.5 1 1.5 2 2.5 3 -0.5 0 1 2 x (m) y (m) undeformed and deformed shapes - disp. amplification factor =1.4225 -1 -0.5 0 1 2 -0.5 0 1 2 yield check - dashed=yielded - disp. amplification factor =1.4225 Figure 3. Top: Undeformed and deformed shapes of the “test truss structure”. Bottom: “Yield check” figure: the yielded truss elements are listed in shown in dashed lines. The (somewhat simplified) screen output is: »truss2d enter the prefix for the input file: 'test_truss'

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4 numnp = 5 numel = 7 numat = 2 numimp = 3 coor = -1 2 0 0 1 2 2 0 3 2 nodal displacements (in m) node 1 x-disp = -0.18033551 y-disp = -0.13404495 node 2 x-disp = 0.00000000 y-disp = 0.00000000 node 3 x-disp = -0.09785255 y-disp = 0.00970755 node 4 x-disp = -0.02800000 y-disp = 0.00000000 node 5 x-disp = -0.09536959 y-disp = 0.03639235 suggested amplification factor = 1.4225 enter the amplification factor (enter 0 to leave unchanged) . ..0 ampli2 = 0 element axial stress element 1 axial_stress = -1.475e+04 Pa element 2 axial_stress = 1.132e+04 Pa element 3 axial_stress = -1.610e+04 Pa element 4 axial_stress = -6.000e+03 Pa element 5 axial_stress = 3.711e+03 Pa element 6 axial_stress = -6.199e+03 Pa element 7 axial_stress = -1.401e+03 Pa yield failure in element 1 : axial stress = -1.475e+04 Pa and yield stress = 1.000e+04 Pa yield failure in element 2 : axial stress = 1.132e+04 Pa and yield stress = 1.000e+04 Pa yield failure in element 3 : axial stress = -1.610e+04 Pa and yield stress = 1.000e+04 Pa support reactions (in N) node # 2 x-reaction = 800.00000 Newtons node # 2 y-reaction = 8192.63230 Newtons node # 4 y-reaction = 2592.63230 Newtons
5 Step 2) Use your code to solve a truss problem similar to that solved for the ANSYS lab

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/16/2010 for the course ME 471 taught by Professor Geubelle,p during the Spring '08 term at University of Illinois, Urbana Champaign.

### Page1 / 15

Computer_assgnt_2_solution - AE 420 / ME 471 - Second FE...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online