Measurement device and method for dynamic stretching crack propagation speed of fragile material

A technology of crack growth speed and dynamic stretching, which is applied in the direction of using one-time impact force to test the strength of materials, can solve the problems of difficult distance guarantee, complicated operation, unsatisfactory response to crack speed changes, etc., to improve measurement accuracy and facilitate operation Effect

Active Publication Date: 2014-05-14
CENT SOUTH UNIV
View PDF3 Cites 21 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The interpretation of the fracture signal is expressed by the measured voltage difference, and the change of ΔR is a continuous value, so that the change of the pressure difference before the resistance wire is disconnected is a slanted line instead of a ladder, thus giving the interpretation of the fracture time It has brought difficulties; while using pencil leads to monitor crack growth, it is difficult to ensure that the distance between the two pencil leads is small during bonding, so the measured values ​​tend to be

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Measurement device and method for dynamic stretching crack propagation speed of fragile material
  • Measurement device and method for dynamic stretching crack propagation speed of fragile material
  • Measurement device and method for dynamic stretching crack propagation speed of fragile material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] See attached figure 1 , 2 , 3, 4, 5, a kind of measuring device of the dynamic tensile crack propagation speed of brittle material of the present invention, described measuring device comprises SHPB device, sample 5, high-speed camera 4; SHPB device is made of incident rod 2, transmission rod 6 , a buffer rod 7 is formed; a circular through hole is prefabricated in the center of the sample 5, and the sample 5 is clamped between the incident rod and the transmission rod of the SHPB device according to the operating requirements of the SHPB device; the high-speed camera 4 Installed on the axis of the circular through-hole of the sample, and the end face of the lens of the high-speed camera is parallel to the surface of the sample with a circular through-hole, and the parameters of the high-speed camera are set reasonably according to the size of the sample, so that the lens window can just completely cover the whole sample.

[0027] In the present embodiment, sample is ...

Embodiment 2

[0036] Using the same marble sample as in Example 1, the diameter of the central circular through hole is reduced to 12.0mm, i.e. r=6.0mm, the size of the sample and the test implementation steps are the same as in Example 1, and the tensile crack runs through the surface of the sample Bifurcation occurs before, the length of tensile crack growth L=22.2mm is measured by the photo, and the tensile crack growth time T=NΔt=60μs; the data can be substituted into the available, the sample dynamic tensile crack growth speed V C =370m / s.

Embodiment 3

[0038] Using the same marble sample as in Example 1, the diameter of the central circular through hole is reduced to 10.0mm, i.e. r=5.0mm, the sample size and test implementation steps are the same as in Example 1, and the crack growth time T=NΔt=80μs , the tensile crack basically runs through the surface of the sample, and the measured tensile crack growth length L=24.8mm; substituting the data into the available, the sample dynamic tensile crack growth speed V C =310m / s.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Radiusaaaaaaaaaa
Outer diameteraaaaaaaaaa
Login to view more

Abstract

The invention discloses a measurement device for the dynamic stretching crack propagation speed of a fragile material. The measurement device comprises an SHPB (split Hopkinson pressure bar) device, a specimen and a high-speed camera, wherein a round through hole is preformed in the center of the specimen, and the specimen is clamped between an incident rod and a transmission rod of the SHPB device; the high-speed camera is installed on an axis of the round through hole of the specimen. The measurement method comprises the following steps: applying impact load to the specimen by utilizing the SHPB device so as to enable a material to be cracked; meanwhile, shooting an image on the surface of the specimen in real time, confirming the crack starting and stopping time according to the record of the image, measuring the length of the crack actually, and calculating the dynamic stretching crack propagation speed. The measurement device and method provided by the invention can control the dynamic stretching crack propagation direction of the fragile material, and also can precisely confirm the crack propagation starting and stopping time, effectively improve the measurement precision of dynamic stretching crack propagation speed of the fragile material, and provide a novel conveniently operated, rapid, convenient, simple and effective method for confirming the dynamic stretching crack propagation speed of the rock-type fragile material under the impact load effect.

Description

technical field [0001] The invention relates to a measuring device and a measuring method for the dynamic tensile crack growth rate of brittle materials, in particular to a measuring device and a measuring method for the dynamic tensile crack growth rate of rock-like brittle materials; belonging to the technical field of brittle material performance measurement. technical background [0002] Crack growth rate is a fundamental parameter in fracture mechanics. Determining the crack growth rate of brittle materials is of great significance for predicting the failure time of brittle materials under the action of accidental loads (such as explosions, earthquakes, etc.) The effect of fracturing also has important engineering practical value. On the other hand, the tensile strength of brittle materials is much lower than its compressive strength and shear strength, and brittle materials usually fail in tension when loaded, so it is more practical to determine the tensile crack gro...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01N3/30
Inventor 李地元成腾蛟周韬李夕兵
Owner CENT SOUTH UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap