Scaling Law for Criticality Conditions in Heterogeneous Energetic Materials under Shock Loading

TL;DR

This paper develops a scaling law to determine the critical conditions for hot spot initiation in heterogeneous energetic materials under shock loading, highlighting the influence of material properties and void morphology.

Contribution

It introduces a scaling-based criterion for hot spot criticality in porous energetic materials, considering material reactivity and void size under shock impact.

Findings

Criticality depends on shock pressure and void size.

Material reactivity significantly influences hot spot initiation.

Scaling law applies to different energetic materials like HMX and TATB.

Abstract

Initiation in heterogeneous energetic material (HEM) subjected to shock loading occurs due to the formation of hot spots. The criticality of the hot spots governs the initiation and sensitivity of HEMs. In porous energetic materials, collapse of pores under impact leads to the formation of hot spots. Depending on the size and strength of the hot spots chemical reaction can initiate. The criticality of the hot spots is dependent on the imposed shock load, void morphology and the type of energetic material. This work evaluates the relative importance of material constitutive and reactive properties on the criticality condition of spots. Using a scaling-based approach, the criticality criterion for cylindrical voids as a function of shock pressure, Ps and void diameter, Dvoid is obtained for two different energetic material HMX and TATB. It is shown that the criticality of different energetic materials is significantly dependent on their reactive properties.