MEASURING FRACTURE TOUGHNESS - A SIMPLIFIED APPROACH USING CONTROLLED CRACK PROPAGATION
DURING THE LOADING CYCLE OF THE CONVENTIONAL FRACTURE TOUGH- NESS TEST, THE POINT OF LOAD APPLICATION REMAINS FIXED WITH RESPECT TO SPECIMEN GEOMETRY EXCEPT FOR SMALL DISPLACEMENTS IN-LINE WITH THE APPLIED LOAD. BY CONTRAST, IN THE PRESENT METHOD THE POINT OF LOAD APPLICATION ADVANCES TOWARD THE CRACKFRONT DURING THE LOADING CYCLE IN A PATH PARALLEL TO THE PLANE OF THE CRACK. SINCE DISPLACEMENT IS THE CONTROLLED VARIABLE, IT IS THUS POSSIBLE TO OBTAIN A CONTINUOUS FUNCTIONAL RELATIONSHIP BETWEEN LOAD AND CRACKLENGTH. IT IS SHOWN THAT THIS RELATIONSHIP IS DIRECTLY RELATED TO THE STRAIN ENERGY RELEASE RATE ON CRACK ADVANCE. THE CONCEPT REDUCES THE COMPLEXITY OF FRACTURE TOUGHNESS TESTING TO A LEVEL COMPARABLE TO A CONVENTIONAL TENSION TEST, THAT IS, RECORDING OF LOAD AND DISPLACEMENT. CHARACTERISTIC FEATURES OF THE METHOD ARE VERY STABLE CRACK PROPAGATION, EFFICIENT USE OF TEST MATERIAL, AND THE ABILITY TO MEASURE TOUGHNESS GRADIENTS. RESULTS OF APPLYING THE CONCEPT TO A 7075-T6 ALUMINUM ALLOY ARE PRESENTED. (A)
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Corporate Authors:
American Society for Testing and Materials (ASTM)
100 Barr Harbor Drive, P.O. Box C700
West Conshohocken, PA United States 19428-2957 -
Authors:
- Weitzmann, R H
- Finnie, I
- Publication Date: 1972-9
Language
- English
Media Info
- Features: Figures; Photos; References;
- Pagination: p. 294-8
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Serial:
- Journal of Materials
- Volume: 7 N3
- Publisher: American Society for Testing and Materials (ASTM)
Subject/Index Terms
- TRT Terms: Aluminum alloys; Bridge design; Bridges; Cracking; Dislocation (Geology); Fracture mechanics; Loads; Structural design; Toughness
- Uncontrolled Terms: Crack propagation
- Old TRIS Terms: Bridge dynamics; Loading period
- Subject Areas: Bridges and other structures; Highways;
Filing Info
- Accession Number: 00210239
- Record Type: Publication
- Source Agency: Transport and Road Research Laboratory (TRRL)
- Files: TRIS
- Created Date: Jul 31 1974 12:00AM