A note on the constant characteristic time of failure incubation processes under various high-rate loads

TL;DR

This paper identifies a constant characteristic time in micro-structural failure processes across various high-rate loads, enabling better prediction and assessment of material failure in dynamic conditions.

Contribution

It demonstrates the existence of a constant characteristic time before failure in brittle materials under high-rate loads and shows how to experimentally determine and utilize it for failure prediction.

Findings

Characteristic time is constant across different high-rate loads.

Experimental determination of this time is feasible.

It can be used to predict failure stresses and times.

Abstract

The research reveals the existence of a constant characteristic time of preparatory micro-structural processes before the onset of macro-failure at various high loading rates of brittle and quasi-brittle materials. The presence of this characteristic is analysed based on available data in the literature from dynamic tests for uniaxial compression and splitting. It is shown that the characteristic time can be determined experimentally and used to calculate the strain rate dependencies of either critical failure stresses or time to failure, at least in the case of linearly growing loads. In addition, it is discussed that the presence of this constant parameter opens up a prospective opportunity for research and development of new methods for assessing the structural-temporal and scale characteristics of the strength and failure of materials under dynamic loads.