암반시료의 AE균열측정과 변형측정

영신컨설턴트 (02) 529 8803 ystcha@naver.com 2022 3

 

acoustic velocity transducer는 암석의 압축파P 전단파S를 측정할 수 있고 BENDER ELEMENT와 유사하고 piezo ceramic element가 노출되지 않아 고압 고하중에 견딜 수 있다. 센서 시료의 top cap pedestal에 내장되고 시료의 옆면에 부착 가능합니다.

Axial Load	Up to 2MN
Data Acquisition	16 Bit (Typically 12/14 at high logging rates)
연직 하중 Load Range (kN)	250 (Axial Load)
구속응력 Pressure Range (MPa)	64
시료직경 Sample Sizes	25, 38, 50mm
Weight Approx (kg)	Sample set 3.3 kg, Pedestal 0.95 kg &Top Cap 1.4 kg

 

acoustic velocity wave

시료크기 직경과 높이 100 mm in diameter and 200 mm in length.

 

GDS LVDT LOCAL STRAIN TRANSDUCERS

 

High pressure version for use in non-conducting oil up to 200MPa (Pressure relieved).

 

Displacement Accuracy	0.1% FRO
Displacement Range	+/- 2.5mm or +/-5.0mm
Displacement Resolution	+/- 2.5mm = <0.1μm, +/- 5.0mm = <0.2μm typical values but dependant on data acquisition used
Sample Sizes	50mm, 70mm, 76mm, 100mm, 150mm, custom
Weight Approx (kg)	: Radial Caliper Weight, (based on a nominal 70mm caliper) = 74g : Axial Apparatus Weight (1 off) = 26g : Transducer Weight (1 off LVDT) = 20g

 

수직 수평방향 변형, AE 측정

 

시료제원

Mechanical properties

Compressive strength 15.64 MPa (11.7 ton/78.5cm2)

Modulus of deformation 3.99 GPa

Tensile strength 1.21 MPa

Poisson’s ratio 0.25

Bulk density 1.22 g/cm3

 

시험기 제원

450-ton servo-control loading system

진동하중 Cyclic loading acoustic emission experiments with different stress levels:

 

Four (4) different maximum stress levels, 3.92 MPa, 6.87 MPa, 8.83 MPa, and 11.77 MPa are chosen for the cyclic loading

 

 

진동 시 수직 수평변형

cyclic stress-strain curves at stable fracture propagation former section

 

진동하중과 AE

Cyclic loading acoustic emission experiment with unstable fracture propagation section

 

균열시작과 종료

Relationship between crack growth velocity and crack length

 

 

수속응력에 따른 수평-수직응역

200MPa=2000kg/cm2. 직경 5cm , 19.6cm2, 39.25ton