Solid and Fracture Mechanics Laboratory

Southwest Research Institute (SwRI) has a number of mechanical properties laboratories equipped to meet a variety of testing needs. The Solid and Fracture Mechanics Laboratory within the Mechanical Engineering Division has 18 closed-loop, servo-hydraulic testing systems providing load capacities between 1,000 and 200,000 pounds. These machines are well equipped to perform both standard as well as highly specialized fatigue and fracture tests. These tests can be performed at ambient, cryogenic, or high temperatures using coupon specimens or more realistic geometries simulating an in-service structure. The laboratory is staffed with a number of experienced technicians, who have amassed more than 75 years of materials testing experience. This staff, combined with the diverse range of equipment listed below, can satisfy a broad range of material testing needs.

Closed Loop Materials Test Systems

Electro-Mechanical
1 at 22,000 lbs, 1 at 400,000 lbs

Servo-Hydraulic
1 at 1,000 lbs
7 at 10,000 lbs
2 at 22,000 lbs
2 at 50,000 lbs
3 at 110,000 lbs
1 at 150,000 lbs
2 at 200,000 lbs
1 biaxial test system (10,000 lbs axial, 3,000 in-lbs torsion/internal pressure)

Data Acquisition and Computer Equipment

• 9 fully automated FCG control PCs:
  Full spectrum loading and non-visual crack length capability
  
  
• 6 Labview data acquisition systems:
  16 bit, 16 channel single ended inputs or 8 channel differential inputs, 100 kHz max sample rate. Installed data acquisition boards also include 2 channel 16 bit D/A outputs, 2 each 24 bit counters, and 8 channels digital input/output
  
  
• Non-visual crack length measurement:
  Potential drop (DC or AC), elastic compliance
  
  
• 12 channels of FRACTOMAT crack growth instrumentation (indirect DCPD system)
  
  
• High speed 12 bit, 1 MHz transient digital storage recorders (8 channels)
  
  
• 2 MTS micro-profilers (arbitrary waveform generation)
  
  
• 3 high temperature 2,200 degrees F extensometers
  (1-inch gage length)
  
  
• 1 high temperature 2, 200 degrees F diametric strain transducer
  
  
• 1 Z-mike laser extensometer.
  
  
• Local area network (LAN) with ethernet connection to SwRI computing facilities
  
  
• 28 strain gage conditioning amplifiers

Additional Test Facilities

Additional specialized equipment exists for creep testing (ambient and high temperature), high rate fracture testing, environmental and temperature control, and a number of other mechanical test arrangements.

Creep Facilities

• Computer-automated creep crack growth systems operating at a maximum of 1,800 degrees F
  
  
• Creep/fatigue testing with long hold times and a maximum of 1,800 degrees F
  
  
• Creep frame for ceramic testing
  (4,000 degrees F compression, 2,900 degrees F tension)
  
  
• Creep-rupture testing in unusual environments

High Rate Test Systems

• Tension/compression split Hopkinson pressure bar
  maximum bar stress = 120 ksi
  temperature range -320 degrees F to 500 degrees F
  
  
• Compression split Hopkinson pressure bar with confining pressure
  maximum bar stress = 340 ksi
  maximum confining pressure = 25 ksi at 75 degrees F
  temperature range = -320 degrees F to 2,500 degrees F (without confining pressure)
  
  
• High speed torsional machine (2,700 in-lbs)
  
  
• Coupled pressure bars for dynamic fracture toughness testing

Temperature and Environmental Control

• 6 resistance and quartz lamp coaxial ovens
  maximum of 2,000 degrees F
  
  
• Centorr vacuum furnace (maximum of 2,300 degrees C)
  
  
• 2 induction heaters:
  20 kW (425 kHz), 10 kW (10 kHz)
  
  
• Environmental chambers: temperature/humidity, ultra-low humidity, vacuum
  
  
• High-temperature ceramic test system with super grip, capacitive extensometry and Super-Kanthal, or induction heating furnaces

Impact Loading and High Cycle Fatigue

• RR Moore rotating beam fatigue tester
  (10,000 cycles per minute)
  
  
• Sheet bending fatigue
  
  
• High cycle fatigue testing (~ 2 kHz)

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