Scaling Behavior in Quasi Static and Impact Fragmentation of Brittle Materials

摘要

An investigation was conducted to examine experimentally the process of fragmentation of brittle materials (glass plates and quartz rods) under quasi-static and dynamic loading conditions.In the quasi-static tests of glass plates,two types of scaling laws were considered.Of these,one was based on the fractal relation similar to the Dielectric Breakdown Model or the Diffusion-limited Aggregation Model,and the other involved the definition of the fragment size distribution.The results of investigation indicate that fragment size distributions mainly follow power-law distributions.Variations in the fragmentation mechanism correlate with quantitative changes in the fractal dimension observed in different regions of the fragmented specimen.The dynamic fragmentation statistics was studied in the recovery experiments with quartz cylindrical rods.The mechanoluminescence-based method was used to measure the distribution of time quantities.Impact loading applied to specimens leads to the formation of fracture surfaces,which produces intensive light emission registered then by Photo Multiplayer Tubes.The data recovery technique allows us to save the fragments and to determine the size distribution of fragments.Both the fragment size distribution and the time interval distribution show evidence of obeying scaling laws.