MPRL Facilities
Tensile and Fatigue Test Facilities
Fourteen closed-loop, servohydraulic testing systems are available for monotonic, low cycle/high cycle fatigue testing, fatigue crack propagation and fracture studies. Twelve of these machine have a capacity at or exceeding 10 tons. Either load, specimen gage length displacement, or stroke of the crosshead/ram can be prescribed to follow a desired function, at frequencies in the range of 0.0001-100 Hz, by means of closed-loop control. Dedicated or mobile computer control is available on most systems. One 10-ton screw driven Instron machine is available for performing monotonic and low cycle fatigue testing. It can also be fitted with a 1/2-ton load cell for accurate mechanical property measurements of small samples. For even more accurate measurements there is a 50 Kg screw driven table top MTS machine. Most systems routinely support testing at temperatures ranging from room temperature to 1000°C, and equipment is available for tests with temperatures up to 1600°C. A computer-controlled, axial-torsional load frame with high temperature capability is available for multiaxial studies.
Crack length can be measured during tests using mechanical, optical, electric potential or unloading compliance methods. An assortment of high precision diametral and longitudinal strain extensometers, including a ZYGO laser extensometer capable of resolving displacements of 10-6 in, are available for use over a wide range of temperatures and frequencies.
The laboratory routinely conducts tensile, cyclic stress-strain, low cycle and high cycle fatigue, plane strain fracture toughness (KIC), stable crack growth (JR-resistance curve), and fatigue crack growth tests over a wide range of temperatures on metallic and non-metallic materials.