Analogue calculator converts output from strain gauges - for both static and dynamic forces in installation of three gauges at 45 deg.

摘要

Analogue calculations are made on strain gauges signals to convert the readings into the principal deformations. The particular case of 3 gauges at angles of 45 deg. is shown with their output a, b, c, applied two a circuit containing two op-amps, two analogue squaring modules, a summing op-amp and followed by an analogue square root module. The output of the last, together with the inputs and intermediate signals gives the two principal strains. The circuit given can handle both steady state and dynamic or transient strain gauge signals. With the Poisson ratio set by potentiometers further circuitry converts the signals already calculated into stress readings while further circuitry converts these in turn into the maximum absolute sheer stress and the Von Mises equivalent stress.