33.2 Stress linearization example

Figure 33–2 shows an example of a stress line defined for an axisymmetric model of a pressure vessel.

Figure 33–2 Stress line through an axisymmetric model of a pressure vessel.

The stress line Section_A_B is defined through the vessel wall. Figure 33–3 and Figure 33–4 show the basic settings and computations, respectively, that you use to linearize the S22 stress component for the undeformed model shape.

Figure 33–3 Stress linearization basic specifications.

Figure 33–4 Stress linearization computations.

When you click OK or Apply in the Stress Linearization dialog box, ABAQUS/CAE creates an X–Y plot of the S22 stress component (oriented normal to the stress line) and of the resulting linearized stresses, as shown in Figure 33–5.

Figure 33–5 Linearized stress plot.

The following output is also written to a file called linearStress.rpt:

********************************************************************************
Statically Equivalent Linear Stress Distribution across a Section,
written on Wed Mar 24 15:05:47 2004

Source
-------

   ODB: Job-1.odb
   Step: Step-1
   Frame: Increment      1: Step Time =    1.000

Linearized Stresses for stress line 'Section_A_B'

                       X           Y           Z       XY Shear 
                     Stress      Stress      Stress      Stress  
     Membrane    
(Average) Stress     -388.19     1493.14     1497.67     74.0502  

  Membrane plus  
Bending, Point 1    -737.581     1889.06     1770.23     74.0502  

  Membrane plus  
Bending, Point 2    -98.2912      1124.3     1245.32     74.0502  

-------------------------------- INVARIANT RESULTS --------------------------
Bending components in equation for computing
membrane plus bending stress invariants are:   S22
                      Max.        Mid.        Min.       Tresca       Mises  
                      Prin.       Prin.       Prin.      Stress      Stress  
      Membrane    
(Average) Stress     1497.67     1496.05    -391.101     1888.77     1887.96

  Membrane plus  
Bending, Point 1     1891.47     1497.67    -390.596     2282.06     2112.87

  Membrane plus  
Bending, Point 2     1497.67     1127.92    -391.807     1889.47     1734.41

The Y Stress corresponds to the S22 stress shown in Figure 33–5. The actual stress values plotted in the curve Section_A_B_S22 do not appear in the report. The linearized membrane and membrane-plus-bending stress curves are generated from the values shown for Y Stress. The reported invariants are calculated from the selected linearized components.