• Sandwich panel
• NASTRAN
• Insert
• Insert Design Handbook
• Honeycomb
• ECSS
• Test

The present work aims to experimentally characterize a type of insert used for sandwich panels in space applications.
This thesis was developed during a period of internship at Thales Alenia Space Italia in Turin.
Sandwich structures can be used every time a combination of minimum weight with high mechanical characteristics is required.
A panel so formed, or in general a plate, is not able to withstand concentrated loads in the direction of its thickness. For this reason, the use of rigid fasteners allows a sandwich panel to tolerate concentrated loads along the thickness. So inserts permit to introduce concentrated loads in honeycomb sandwich plate.
This is the main objective of inserts. The studied insert is non-standard.
Therefore a test campaign was needed. In fact this thesis activity started after a first phase of bibliographic investigation on inserts and test methods based on regulations issued by the ECSS (European Cooperation for Space Standardization).
The allowable values were calculated through statistic analysis of tests results.
Then a numerical correlation of models allows to have predictive FEM models.
The activity was divided into three phases:
- Analytical
- Numerical
- Experimental
The analytical part consists of the calculation of standard insert allowable values with the Insert Design Handbook. Moreover samples are designed according to regulations and the non-standard insert is planned according to technical specification.
The numerical phase presents the calculation and the samples modelization with FEM.
The FEM models aim to predict allowable values of the insert.
In the experimental part the tests are realized and the obtenined results are elaborated and used to calibrate the FEM models.
Comparing the obtained results with standard insert allowable values it was possible to understand that there were performance increases.