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Fracture Mechanics (FML) Laboratory

Mikhail A. Sokolov, Task Leader
Tel: 865.574.4842
Fax: 865.574.0641
email: sokolovm@ornl.gov

 
The objectives of this group are to advance understanding of material fracture processes, to develop test procedures to measure materials' resistance to fracture, and to characterize materials to provide support for efforts to ensure the integrity of engineering structures and in the development of new materials.
 
Capabilities
Computer-controlled servohydraulic testing machines with capacities from 44,500 to 1,100,000 Newtons, used to perform tensile, fracture toughness, fatigue crack growth and crack arrest toughness testing. Available furnaces permit testing from -320 to 1000 degrees centigrade.
  • Screw-driven mechanical tensile testing machine with a 44,500 Newton capacity
  • Two 89,000 Newton servohydraulic machines equipped with environmental chambers for fracture toughness and fatigue crack growth testing in a controlled atmosphere or in a vacuum
  • Drop weight and instrumented Charpy machines for impact testing
  • Automated ball indentation device for measuring flow properties of materials in very localized regions
  • Remote hot cell testing of irradiated materials using instrumented Charpy machine, a 445,000N servohydraulic test machine, and an automated ball-indentation system
  • Scanning electron microscope with a large specimen chamber for fractographic studies
  • Computerized high-speed data aquisition, test analysis, and test control systems
  • Heat-treatment furnaces to control heating and cooling of specimens
Research Scope
  1. Experimental fracture mechanics with emphasis on elastic-plastic behavior to provide techniques for characterizing material parameters critical to the fracture process
  2. Fracture studies of low-alloy pressure vessel steels to provide engineering data for structural integrity assessments of pressure vessels used in energy production
  3. Irradiation studies of low-alloy steels and stainless steels to determine the effects of neutron irradiation on mechanical properties and fracture toughness of light-water nuclear reactors
  4. Fracture toughness studies of graphite materials for nuclear reactor and space applications
  5. Assessment of prestressed concrete for design of pressure vesels for high-temperature nuclear and fossil energy applications
  6. Fracture toughness studies for nodular cast irons with emphasis on microstructural interactions
  7. Metallurgical studies of nuclear reactor vessels to simulate properties for performance of large fracture mechanics experiments
Task Members: