2. Benchmark solution#

2.1. Calculation method used for the reference solution#

2.1.1. Modeling A#

The equations governing behavior are nonlinear differential equations. To validate the response obtained with Code_Aster in nonlinear statics, the values obtained are compared with the analytical values.

2.2. Benchmark results#

The comparison is carried out on the moments (“MZ”) obtained as a function of the rotations” DRZ “imposed for the various elements and the loads applied, with a calculation time step of \(1.0s\). The moments are in \(s\) and the moments in \(N\mathrm{.}m\).

The curves below make it possible to verify that threshold crossings and slope changes are detected and taken into account even with a very rough calculation step.

_images/10000201000005F7000003E6629FC035A4B46810.png

Figure 2.2-a : Curve Moment-rotation, element 1.

The answer given by*Code_Aster* is tested for the following values:

Table 2.2-a : rotations and moments, element 1.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

1.0000000000E+00

1.0000000000E+03

1.0000000000E-03

1.0000000000E-03

3.0000000000E+00

-1.0000000000E+03

-1.0000000000E-03

-1.0000000000E-03

5.0000000000E+00

1.4000156777E+03

3.0000000000E-03

3.0000000000E-03

7.0000000000E+00

-1.6500032505E+03

-3.0000000000E-03

-3.0000000000E-03

9.0000000000E+00

1.8000256320E+03

5.0000000000E-03

5.0000000000E-03

1.1000000000E+01

-1.8500108811E+03

-5.0000000000E-03

-5.0000000000E-03

1.3000000000E+01

2.2000192257E+03

1.1000000000E-02

1.1000000000E-02

1.5000000000E+01

-2.4833453804E+03

-1.1000000000E-02

-1.1000000000E-02

1.7000000000E+01

2.3601391920E+03

1.5000000000E-02

2.3601391920E+03

1.9000000000E+01

-2.6166696872E+03

-1.5000000000E-02

-1.5000000000E-02

2.1000000000E+01

2.5600393177E+03

2.0000000000E-02

2.0000000000E-02

2.3000000000E+01

-2.7833327927E+03

-2.0000000000E-02

-2.0000000000E-02

_images/10000201000005F7000003E61295576838939B58.png

Figure 2.2-b : Curve Moment-rotation, element 2.

The answer given by*Code_Aster* is tested for the following values:

Table 2.2-b : rotations and moments, element 2.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

1.0000000000E+00

-1.0000000000E+03

-1.0000000000E-03

-1.0000000000E-03

3.0000000000E+00

1.0000000000E+03

1.0000000000E-03

1.0000000000E-03

5.0000000000E+00

-1.6500000701E+03

-3.0000000000E-03

-3.0000000000E-03

7.0000000000E+00

1.4000143913E+03

3.0000000000E-03

3.0000000000E-03

9.0000000000E+00

-1.8500245881E+03

-5.0000000000E-03

-5.0000000000E-03

1.1000000000E+01

1.8000013063E+03

5.0000000000E-03

1.10000000E-03

1.3000000000E+01

-2.4500169230E+03

-1.1000000000E-02

-1.1000000000E-02

1.5000000000E+01

2.200015606060E+03

1.1000000000E-02

1.7000000000E+01

-2.6166668190E+03

-1.5000000000E-02

-1.5000000000E-02

1.9000000000E+01

2.3601185361E+03

1.5000000000E-02

2.3601185361E+03

2.1000000000E+01

-2.7833347518E+03

-2.0000000000E-02

-2.0000000000E-02

2.3000000000E+01

2.560038303030E+03

2.0000000000E-02

_images/10000201000005F7000003E6E477314F4FEE71E9.png

Figure 2.2-c : Curve Moment-rotation, elements 5 and 6.

Table 2.2-c : rotations and moments, elements 5 and 6.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

3.0000000000E+00

1.8000004556E+03

5.0000000000E-03

1.8000004556E+03

6.0000000000E+00

2.1600162134E+03

1.0000000000E-02

2.1600162134E+03

9.0000000000E+00

2.3600225066E+03

1.5000000000E-02

2.3600225066E+03

1.2000000000E+01

2.5599993245E+03

2.0000000000E-02

1.5000000000E+01

1.1054534813E+03

1.5000000000E-02

1.5000000000E-02

1.8000000000E+01

-1.2000046711E+03

1.0000000000E-02

1.2000046711E+03

2.1000000000E+01

-1.9499993974E+03

5.0000000000E-03

-1.9499993974E+03

Table 2.2-d : rotations and moments, element 3.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

1.0000000000E+00

1.1904121201E+03

1.1545287124E-03

1.1904121201E+03

3.0000000000E+00

-1.3331111483E+03

-1.1545081204E-03

-1.3331111483E+03

5.0000000000E+00

1.7237265601E+03

3.4638528074E-03

3.4638528074E-03

7.0000000000E+00

-1.9588403006E+03

-3.4638188809E-03

-3.4638188809E-03

9.0000000000E+00

2.2570514348E+03

5.7731769015E-03

2.2570514348E+03

1.1000000000E+01

-2.2255575302E+03

-5.7731814447E-03

1.3000000000E+01

2.6190094112E+03

1.2701327870E-02

2.6190094112E+03

1.5000000000E+01

-2.9330146633E+03

-1.2701282573E-02

-2.9330146633E+03

1.7000000000E+01

2.8324211293E+03

1.7320099228E-02

2.8324211293E+03

1.9000000000E+01

-3.1107779579E+03

-1.7320059070E-02

-3.1107779579E+03

2.1000000000E+01

3.0989885500E+03

2.3093563448E-02

2.3000000000E+01

-3.3330038571E+03

-2.3093529688E-02

-3.3330038571E+03

Table 2.2-e : rotations and moments, element 4.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

1.0000000000E+00

-1.3331111481E+03

-1.1545081204E-03

-1.3331111481E+03

3.0000000000E+00

1.1904121201E+03

1.1545287124E-03

1.1904121201E+03

5.0000000000E+00

-1.9588485809E+03

-3.4638188656E-03

-3.4638188656E-03

7.0000000000E+00

1.7237108264E+03

3.4638528189E-03

3.4638528189E-03

9.0000000000E+00

-2.2255289211E+03

-5.7731814457E-03

-2.2255289211E+03

1.1000000000E+01

2.2570794615E+03

5.7731768999E-03

2.2570794615E+03

1.3000000000E+01

-2.9330774561E+03

-1.2701282533E-02

1.5000000000E+01

2.6190179987E+03

1.2701327871E-02

2.6190179987871E-02

1.7000000000E+01

-3.1108083764E+03

-1.7320059051E-02

-3.1108083764E+03

1.9000000000E+01

2.8325478530E+03

1.7320099228E-02

2.1000000000E+01

-3.3330092804E+03

-2.3093529684E-02

2.3000000000E+01

3.0989396258E+03

2.3093563476E-02

Table 2.2-f : rotations and moments, element 7.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

3.0000000000E+00

2.2570241105E+03

5.7731769185E-03

2.2570241105E+03

6.0000000000E+00

2.5656146751E+03

1.1546635072E-02

9.0000000000E+00

2.8326866571E+03

1.7320099213E-02

2.8326866571E+03

1.2000000000E+01

3.0989736939E+03

2.3093563449E-02

3.0989736939E+03

1.5000000000E+01

1.1994330950E+03

1.7320334952E-02

1.8000000000E+01

-1.8045529425E+03

1.1547265855E-02

-1.8045529425E+03

2.1000000000E+01

-2.2218840472E+03

5.7738233936E-03

-2.2218840472E+03

Table 2.2-g : rotations and moments, element 8.

Moment

rotation \({\theta }_{z}\)

Moment \({M}_{z}\)

3.0000000000E+00

4.6662898355E+06

3.0801270189E-03

4.6662898355E+06

6.0000000000E+00

9.3318646247E+06

6.1602540378E-03

9.0000000000E+00

1.3997034885E+07

9.2403810568E-03

1.2000000000E+01

1.8662205044E+07

1.2320508076E-02

1.5000000000E+01

1.3996314269E+07

9.2403810568E-03

1.8000000000E+01

9.3304234944E+06

6.1602540378E-03

2.1000000000E+01

4.6637232079E+06

3.0801270189E-03

4.6637232079E+06

2.3. Uncertainty about the solution#

2.3.1. Modeling A#

The reference solution is obtained by numerical integration of a nonlinear differential system.