An apparatus for the measurement of tensile creep and contraction ratios in small non-rigid specimens

摘要

An apparatus is described for precise measurement ofcreep properties in specimens with gauge lengths down to 1.2cm. An extensometer has been developed which is supportedindependently of the specimen and exerts a load on the specimenof less than 5 grams. It can thus be used with small non-rigidspecimens. The extensometer will detect strains down to2 x 10-6. The stability is excellent. An adaptation of thesystem which allows simultaneous measurement of tensile strainand lateral strain during creep is also described. The apparatuswas designed for the measurement of anisotropy of creepproperties in oriented thermoplastics and reference to suchmeasurements is given. It is however entirely suitable forgeneral application to small specimens.