130
7 Virtual testing approach for sandwich panel joints
to face adhesive bond is considered, this interface is modelled as kinematic coupling using a tied contact. The performed bending study indicates that this simplified interface
model reproduces the mechanical behavior well.
Sub-component level
Considering the determined relevant mechanical effects of the reference test, the cohesive model for the debonding of face and adhesive/potting is yet to be determined. This
is done on sub-component level, because it is difficult to conceive a customized investigation that isolates this effect allowing to characterize it on structural element level. A
corresponding test setup, which enables to study the debonding of face and potting
would have to be similar or even equal to the reference test. The determination of the
corresponding cohesive model is the only investigation in the last building block and the
synthesis of the model parameters determined on lower building blocks is included in
this investigation. Since, the sub-component level coincides with the reference test, the
physical test results have been available as input for Phase 1 and the structural tests and
analysis methods process step of the investigation procedure is generally not necessary
for sub-component level investigations (see Figure 98).
Figure 98 Process steps of sub-component level investigations
Regarding the demonstration example, the implementation of the top-level virtual test
has not been described in the previous chapters. This is done in the following based on
the two remaining steps of the investigation procedure.
FE-modelling & numerical studies
The top-level FE-model is implemented based on the previous building blocks. Therefore,
basic numerical parameters such as mass scaling, loading rate and element size are
adopted from the structural element building block. Additional mesh convergence studies regarding the face sheet and core have been performed in order to determine an
appropriate local mesh refinement. Other performed numerical studies include the consideration of the fixture, which eventually is included in combination with a penalty contact. This is done in order to represent the effect that the specimen can lift off the fixture
Physical
test
results
Structural tests
and analysis
methods
FE-modelling &
numerical
studies
Model
calibration and
verification
Virtual
test
results
Reference
test input
7 Virtual testing approach for sandwich panel joints
to face adhesive bond is considered, this interface is modelled as kinematic coupling using a tied contact. The performed bending study indicates that this simplified interface
model reproduces the mechanical behavior well.
Sub-component level
Considering the determined relevant mechanical effects of the reference test, the cohesive model for the debonding of face and adhesive/potting is yet to be determined. This
is done on sub-component level, because it is difficult to conceive a customized investigation that isolates this effect allowing to characterize it on structural element level. A
corresponding test setup, which enables to study the debonding of face and potting
would have to be similar or even equal to the reference test. The determination of the
corresponding cohesive model is the only investigation in the last building block and the
synthesis of the model parameters determined on lower building blocks is included in
this investigation. Since, the sub-component level coincides with the reference test, the
physical test results have been available as input for Phase 1 and the structural tests and
analysis methods process step of the investigation procedure is generally not necessary
for sub-component level investigations (see Figure 98).
Figure 98 Process steps of sub-component level investigations
Regarding the demonstration example, the implementation of the top-level virtual test
has not been described in the previous chapters. This is done in the following based on
the two remaining steps of the investigation procedure.
FE-modelling & numerical studies
The top-level FE-model is implemented based on the previous building blocks. Therefore,
basic numerical parameters such as mass scaling, loading rate and element size are
adopted from the structural element building block. Additional mesh convergence studies regarding the face sheet and core have been performed in order to determine an
appropriate local mesh refinement. Other performed numerical studies include the consideration of the fixture, which eventually is included in combination with a penalty contact. This is done in order to represent the effect that the specimen can lift off the fixture
Physical
test
results
Structural tests
and analysis
methods
FE-modelling &
numerical
studies
Model
calibration and
verification
Virtual
test
results
Reference
test input