A comparison of quasi-static indentation and low-velocity impact on composite overwrapped pressure vessels

Abstract

The equivalence of quasi-static indentation and low-velocity impact loading regimes has been assessed for composite overwrapped pressure vessels. Test specimens were assessed in detail in terms of the force–displacement response, and micro-focus computed tomography was used for qualitative and quantitative assessment of the associated damage to the constituent materials/interfaces. The results show that the force–displacement response follows an essentially similar pattern between the two loading regimes (within 10% for all cases). Quantitative assessment of the projected composite damage area and permanent deformation of the aluminium substrate as a function of peak indentor displacement also showed a high degree of equivalence between the loading regimes. It is concluded that quasi-static indentation represents a usable analogue for mechanistic assessment of low-velocity impact damage in the tested composite overwrapped pressure vessels.