• posted

I tried to find a load cell to measure forces and moments in x, y and z directions of a steel columns. Since the strength of the column is huge, so purchasing a load cell with large loading capacity is very expensive. So, i am thinking a possible solution. I just put the strain gages at the root of the steel column. By special setup of the strain gage, i can tell the forces and moments of the column. So, the column itself is a load cell.

Maybe it does not have to be the steel column. I can use another piece of the steel piece with strain gage on, then connect this piece with the steel column, which i want to test.

Does anyone has thus experience before? I know there have several potential problems. However, do you think if it is doable? Any suggestion is appreciated.

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Get a book/mfg-brochure on strain gauges and their use - it's the easiest way for you to get your info and get your measurements accurate -

in short, and light on the details --------------

a load cell is basically a box with a strain gauge inside, used for measuring direct straight force. It does not measure moments

a strain gauge (sensor) is a material that changes electrical resistance proportional to the strain it sees.

stress is related to strain. Knowing the strain tells you the stress of that material, stress which was created by the same load that created the strain

Also, while strain gauges are used to find stress, strain gauges do not measure stress or moments or forces. You can determine force and stress by using a strain gauge at two conditions of loading and some calculations, and you can determine moment by knowing the geometry of the part and the force applied and calculating. Loads that create moments create bending stress and shearing stress, and the strain/stress/force varies from + to - from top to bottom of the member carrying the moment, as well as varying along the long axis of the member continuously and discontinuously.

strain gauges are oriented in the axis desired to be measured, at the location of the area you wish to review, and then they are attached to the surface with their adhesive, measurements taken, and the material loaded. The strain is then measured using a bridge or other like measuring device. Three gauges are needed to measure three axes/ points simultaneously and indepenedently

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