Study on the Effect of Mineral Particle Sizes on the Spectral Characteristics of Sound and Vibrations in Rock Drilling

Table 4

High-low ratio of frequency (λ) for concrete samples with different aggregate sizes.

Feed rate (mm/min)	33.1	47.4	71.6	87.7
Average aggregate size (mm)	0.25
4000–6000 Hz	0.11843036	0.127980472	0.122082455	0.126124159
14000–15000 Hz	0.13187579	0.147968224	0.156227476	0.14774893
High-low ratio (λ)	1.113530264	1.156178136	1.279688197	1.171456218
Average aggregate size (mm)	1.1
4000–6000 Hz	0.113067482	0.128451176	0.129916535	0.129387436
14000–15000 Hz	0.108604888	0.125634557	0.130128317	0.122180644
High-low ratio (λ)	0.960531594	0.978072452	1.001630133	0.944300683
Average aggregate size (mm)	4.4
4000–6000 Hz	0.152988891	0.163404004	0.146624211	0.141636967
14000–15000 Hz	0.124767589	0.114370381	0.115314122	0.114600094
High-low ratio (λ)	0.815533651	0.699923984	0.786460308	0.809111465
Average aggregate size (mm)	14.55
4000–6000 Hz	0.17636855	0.218840959	0.19055561	0.178583591
14000–15000 Hz	0.112965259	0.123606084	0.097188293	0.097987889
High-low ratio (λ)	0.640506821	0.564821523	0.510025884	0.548694807
Average aggregate size (mm)	27
4000–6000 Hz	0.418510364	0.175652912	0.153415494	0.205641333
14000–15000 Hz	0.100756995	0.080204275	0.09358585	0.059427643
High-low ratio (λ)	0.240751494	0.456606581	0.61001564	0.288986859