Failure mechanisms in energy-absorbing composite structures

Abstract

Quasi-static tests are described for determination of the energy-absorption properties of composite crash energy-absorbing segment elements under axial loads. Detailed computer tomography scans of failed specimens were used to identify local compression crush failure mechanisms at the crush front. These mechanisms are important for selecting composite materials for energy-absorbing structures, such as helicopter and aircraft sub-floors. Finite element models of the failure processes are described that could be the basis for materials selection and future design procedures for crashworthy structures.

Keywords:

• crashworthiness
• energy absorption
• composite material
• compressive testing
• fracture
• finite-element modelling

Acknowledgements

The work described here was carried out within a collaboration on crashworthy design between the DLR and the Cooperative Research Centre for Advanced Composite Structures (CRC-ACS), Melbourne. The authors would like to thank in particular Dr R. Thomson and A. Jackson of CRC-ACS for the provision of test specimens and for valuable discussions on both the test and simulation work.