With the aid of display groups, create a tabular data report of the whole model element stresses (components S11, S22, and S12), the reaction forces and moments at the supported nodes (sets EndA and EndB), and the displacements of the midspan nodes (set MidSpan). The stress data are shown below. Field Output Report
Source 1
---------
ODB: SkewPlate.odb
Step: Apply pressure
Frame: Increment 1: Step Time = 1.000
Loc 1 : Integration point values at shell general ... : SNEG, (fraction = -1.0)
Loc 2 : Integration point values at shell general ... : SPOS, (fraction = 1.0)
Output sorted by column "Element Label".
Field Output reported at integration points for part: PLATE-1
Element Int S.S11 S.S11 S.S22 S.S22 S.S12 S.S12
Label Pt @Loc 1 @Loc 2 @Loc 1 @Loc 2 @Loc 1 @Loc 2
-----------------------------------------------------------------------------------------------------
1 1 79.7614E+06 -79.7614E+06 1.1085E+06 -1.1085E+06 -5.86291E+06 5.86291E+06
1 2 83.7703E+06 -83.7703E+06 7.14559E+06 -7.14559E+06 -8.00706E+06 8.00706E+06
1 3 66.9385E+06 -66.9385E+06 2.79241E+06 -2.79241E+06 -1.98396E+06 1.98396E+06
1 4 72.3479E+06 -72.3479E+06 5.05957E+06 -5.05957E+06 -7.0819E+06 7.0819E+06
.
.
48 1 -142.755E+06 142.755E+06 -56.0747E+06 56.0747E+06 21.007E+06 -21.007E+06
48 2 -118.848E+06 118.848E+06 -7.21449E+06 7.21449E+06 4.00065E+06 -4.00065E+06
48 3 -187.19E+06 187.19E+06 -103.31E+06 103.31E+06 50.352E+06 -50.352E+06
48 4 -238.323E+06 238.323E+06 -84.7331E+06 84.7331E+06 70.0676E+06 -70.0676E+06
Minimum -238.323E+06 -90.2378E+06 -103.31E+06 -10.5216E+06 -18.865E+06 -70.0676E+06
At Element 48 4 24 2 12 48
Int Pt 4 4 3 2 4 4
Maximum 90.2378E+06 238.323E+06 10.5216E+06 103.31E+06 70.0676E+06 18.865E+06
At Element 4 48 2 24 48 12
Int Pt 4 4 2 3 4 4
The locations Loc 1 and Loc 2 identify the section point in the element where the stress was calculated. Loc 1 (corresponding to section point 1) lies on the SNEG surface of the shell, and Loc 2 (corresponding to section point 3) lies on the SPOS surface. Local material directions have been used for the element: the stresses refer to a local coordinate system. Check that the small-strain assumption was valid for this simulation. The axial strain corresponding to the peak stress is 0.008. Because the strain is typically considered small if it is less than 4 or 5%, a strain of 0.8% is well within the appropriate range to be modeled with S8R5 elements. The reaction forces and moments are reported in the following table: Field Output Report
Source 1
---------
ODB: SkewPlate.odb
Step: Apply pressure
Frame: Increment 1: Step Time = 1.000
Loc 1 : Nodal values from source 1
Output sorted by column "Node Label".
Field Output reported at nodes for part: PLATE-1
Node RF.RF1 RF.RF2 RF.RF3 RM.RM1 RM.RM2 RM.RM3
Label @Loc 1 @Loc 1 @Loc 1 @Loc 1 @Loc 1 @Loc 1
-------------------------------------------------------------------------------------
3 0. 0. 37.3924 -1.5991 -76.4939 0.
4 0. 0. -109.834 1.77236 -324.424E-03 0.
5 0. 0. 37.3918 1.59909 76.4939 0.
6 0. 0. -109.834 -1.77236 324.411E-03 0.
15 0. 0. 73.6366 8.75019 -62.2243 0.
16 0. 0. 260.424 6.95105 -51.1181 0.
17 0. 0. 239.685 6.56987 -35.4374 0.
28 0. 0. 73.6366 -8.75019 62.2243 0.
29 0. 0. 260.424 -6.95105 51.1181 0.
30 0. 0. 239.685 -6.56988 35.4374 0.
116 0. 0. 6.15382 7.5915 -36.4274 0.
119 0. 0. 455.132 6.80781 -88.237 0.
121 0. 0. 750.805 8.31069 -126.462 0.
123 0. 0. 2.2866E+03 31.0977 -205.818 0.
170 0. 0. 6.154 -7.5915 36.4274 0.
173 0. 0. 455.133 -6.80782 88.237 0.
175 0. 0. 750.805 -8.31069 126.462 0.
177 0. 0. 2.2866E+03 -31.0977 205.818 0.
Minimum 0. 0. -109.834 -31.0977 -205.818 0.
At Node 177 177 6 177 123 177
Maximum 0. 0. 2.2866E+03 31.0977 205.818 0.
At Node 177 177 177 123 177 177
Total 0. 0. 8.00000E+03 -39.2199E-06 -5.00679E-06 0.
The reaction forces are written in the global coordinate system. Check that the sum of the reaction forces and reaction moments with the corresponding applied loads is zero. The nonzero reaction force in the 3-direction equilibrates the vertical force of the pressure load (20 kPa × 1.0 m × 0.4 m). In addition to the reaction forces, the pressure load causes self-equilibrating reaction moments at the constrained rotational degrees of freedom. This example was run as a linear analysis, in which it is assumed that the nodal displacements are small relative to the characteristic structural dimensions. The midspan deflection across the plate, as indicated in the table of displacements (not shown here), is approximately 5.4 cm, or roughly 5% of the plate's length. However, it is questionable whether the displacements are sufficiently small for a linear analysis to provide accurate results. Nonlinear effects in the structure may be important, so we need to run a nonlinear analysis to further investigate this example. Geometrically nonlinear analyses are discussed in Nonlinearity. | |||||||