Multiple-station flexural creep test apparatus

A multiple-station flexural creep test apparatus has been developed to simultaneously evaluate a large number of test specimens subjected to a wide array of testing conditions. The apparatus is relatively simple and inexpensive. Typical specimens used are 15 cm long, 1.3 cm wide and 0.3 cm thick, dead weight loaded in either three- or four-point flexure. Two units have been fabricated to date, each unit being capable of simultaneously testing 135 independently loaded specimens, in three temperature zones of 45 specimens each. Maximum temperature capability in each independently controlled zone is 260 degrees C. A small mirror, bonded perpendicular to the specimen at a support point, is used to determine creep strain. Laser light reflected off the mirror onto a vertical surface some distance away tracks the rotation of the mirror. The large optical magnification achieved provides high resolution even with simple measurement devices such as a meter stick. Verification tests using previously documented materials have demonstrated good correlation with other, more costly creep test methods. Subsequently, the new apparatus has been used continuously to acquire creep data for various types of materials.