Measuring bending stress during axial loading with strain gauge

Discussion in 'The Projects Forum' started by wahiduru, Jan 25, 2010.

  1. wahiduru

    Thread Starter New Member

    Jan 25, 2010
    I'm having problem with one of my intern projects. I was given a raw data of measured strain from a rod with 4 strain gauges. gauge a) 0 b) 90 c) 180 d) 270 degrees. Axial load was applied and the axial strain measurement was recorded. I was asked to find bending stress applied to the rod during the axial loading.

    What i did was to measure the strain differences btwn gauges a & c for vertical bending and d & d for horizontal bending.
    The calculations were easy but the result did not make any sense. The bending percentage were too big to ignore.

    I'm trying to convince my supervisor to to do measurement only for bending using half bridge circuit configurations which will reject axial load and only measure the bending stress.

    Any idea? Really appreciate your opinions.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Without a diagram of the fixture, it's hard to guess about the results. You can go to and get information about how to properly place your strain gauges.