an employee-owned company

Fatigue

We offer a variety of cyclic testing services for examining equipment, products, devices, and components. Our load testing capabilities may be applied in a cyclic manner to assess fatigue behavior, vibration loading, fracture mechanics, damage tolerance and failure mechanisms. We also have the capacity to combine fatigue with other factors, such as bending, internal pressure, temperature, and chemical exposure to assess their combined effects.

  • Full-Scale Component, Small-Scale Component, and Material Coupon
  • Complex and Mixed Loading Scenarios
  • Cracking and Crack Growth Assessment
  • Corrosion Effects
  • Elevated Temperature and Chemical Exposure
  • Four-Point Rotational Bending Testing
  • Drill String Friction Testing
  • Casing and Riser Wear Testing

Resonant Bending Fatigue Testing

Stress Engineering Services is a renowned leader in high-speed fatigue testing of full-scale pipe samples to verify fatigue resistance of connectors, girth welds, pipe metal, and more. These tests involve applying sinusoidal alternating bending stresses around the entire pipe circumference to stimulate the pipe specimen near its resonant bending frequency.  By internally pressurizing the test sample, a mean axial stress can also be supplied.

  • Resistance Fatigue Machines:
    •  7 machines – 3” to 24” (76 to 610 mm) diameter samples
    •  2 machines – 24” to 44” (508 to 914 mm) diameter samples
    •  6 machines – 0.59” to 3” (15 to 76 mm) diameter samples
  • Stress Ranges: typically 5 ksi to 50 ksi (35 to 350 MPa)
  • Cyclic Rates: about 2.5 million cycles per day
  • 24 hour / 7 day Operation with Automatic Shut-Downs
  • Continuous Monitoring of Alternating Fatigue Stresses
  • Post-Mortem Dimensional and Metallurgical Evaluations

 

Resonant Bending Fatigue Testing Animation