Improving Robustness Assessment Methodologies for Structures Impacted by MissileS – IRIS Phase 3

This report presents the description and the interpretation of the tests carried out in the third phase of the NEA Working Group on Integrity and Ageing of Components and Structures (WGIAGE) activity “Improving Robustness Assessment Methodologies for Structures Impacted by MissileS”, called IRIS Phase 3. It is dedicated to the study of vibration propagation in a civil structure submitted to the impact of a deformable projectile. IRIS Phase 3 aimed:
• to give the opportunity to each participant to use their means and tools for calculating the shock propagation and the associated floor response spectra;
• to gather all the results from a series of three impact tests, and to share that data;
• to assess the effect of the local damage caused by the impact on the induced vibrations, the “mechanical effect”;
• to quantify structural damping in the areas that behave as a linear elastic material, and in the damaged areas;
• to assess or upgrade the usual approaches to implement the damping in the numerical calculations;
• to draw on this basis a set of quantitative conclusions on the main parameters (dealing with material properties, boundary conditions, local damage, etc.) that have an influence on the evolution of the shock inside the structure (in terms of magnitude, frequency domains and regarding different quantities of interest suchas displacement, velocity and acceleration);
• to issue a set of recommendations considering the results of both the round robin calculations and the calibration calculations;
• to set up a shared basis of data related to the transmission of the shock inside the structures, the “structural effect”.