Apparatus and method for measuring creep crack growth property using small specimen with micro groove
AssigneeChungang University Industry Academic Cooperation Foundation
InventorsKee Bong Yoon, Thanh Tuan Nguyen
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Abstract
An apparatus and a method for measuring a creep crack growth property using a small specimen with a micro groove are provided. The apparatus for measuring a creep crack growth property includes a lower die on which an edge of the specimen is mounted and which includes a lower die hole formed in the center thereof, an upper die coupled to an upper portion of the lower die so as to fix the specimen, and a punching unit inserted into an upper die hole formed in the center of the upper die so as to press an upper surface of the specimen, wherein a semielliptical micro groove is formed in a lower surface of the specimen to measure a creep crack growth property.
Claims12
An apparatus for measuring a creep crack growth property using a specimen having a micro groove, the apparatus comprising:
- a lower die on which an edge of the specimen is to be mounted, the lower die including a lower die hole formed in a center thereof;
- an upper die coupled to an upper portion of the lower die to fix the specimen;
- and
- a punching unit configured to be inserted into an upper die hole formed in a center of the upper die to press an upper surface of the specimen, the punching unit including a punching ball,
- wherein the micro groove is formed in a semielliptical shape only in a lower surface of the specimen to measure the creep crack growth property,
- wherein the micro groove of the specimen is formed with a dimension determined by a stress intensity factor, and
- wherein the stress intensity factor is obtained from a crack length and a stress value and represents strength of stress field as a physical quantity representing crack tip singularity.
A method of measuring a creep crack growth property using a specimen, the method comprising:
- forming a micro groove in a semielliptical shape only in a lower surface of the specimen to grow a creep crack;
- and
- obtaining data for the creep crack growth property by applying a load on the specimen,
- wherein the micro groove of the specimen is formed with a dimension determined by a stress intensity factor, and
- wherein the stress intensity factor is obtained from a crack length and a stress value and represents strength of stress field as a physical quantity representing crack tip singularity.
Dependencies are inferred from the claim text.