High-speed Tensile Research Articles

Load Cell for High-speed Tensile Testing of Yarns

A high-frequency, responsive-force gauge is needed to observe the actual stress-strain curves of filament yarns in an extreme short loading time ranging in ms during high-speed testing.A standstill indication of the force-gauge must be formed with the D.C out-put, because dead loads are charged to calibrate the gauge with weights.The force gauge of a yarn-measuring instrument must have temperature stability and zero-level stability.We have designed and built a high-frequency, responsive-force gauge with which to investigate the mechanical behavior of a filament yarn. The gauge is based on the principle that the frequency of a zero temperature coefficient (A.T Type) quartz crystal resonator of radio frequency shifts under external pressure.The characteristics of the quartz crystal resonator force gauge show that the frequency response is from D.C to about 6-7KHz and stable both in the initial drift and temperature drift.Further work is in progress to improve the mechanism of the force gauge so as to obtain a higher response.

高速引張試験用荷重計の試作

高速引張試験用荷重計の試作

A study of polymer film brittleness

AbstractThe inability of polymer chains to deform the required amount within the time allowed by a stress‐to‐failure event results in brittle failure. Factors related to brittle behavior of films were investigated. By both conventional and novel testing techniques, stress–time–temperature relationships were studied to determine the brittle point. From high‐speed tensile tests at strain rates up to 106%/min., the critical strain rate (incipient brittleness as indicated by failure accompanied by a marked decrease in ductility) was determined for representative films. High‐speed motion pictures (6,000 frames/sec.) of film failure in rice bag drop tests, were used to ascertain the time of deformation to be related to brittleness. Deformation rates were calculated to be of the order of 130 to 230 × 103%/min.

An Autographic Method for Obtaining Load-Extension Records of High-Speed Tensile Tests on Sheet Specimens at Elevated Temperatures

An Autographic Method for Obtaining Load-Extension Records of High-Speed Tensile Tests on Sheet Specimens at Elevated Temperatures