fatigue test

[M.P.Singh]

can u give me the steps how to use labview in fatigue test. i am conducting fatigue test on constant bending stress machine where the specimen will be rotating at 4200 rpm .how to acquire the strain signal from a rotating specimen.i am thinking to measure the crack length also

[muks]

what is the hardware that you are/planning to use?

[jyothi prasad]

it is a traditional machine on which specimen will be rotating.now my question is how to acquire signal from a rotating specimen.

can u suggest me the module.we have national instruments CETRE FOR EXCELLENCE in our college.i was thinking to acquire the strain signal

[muks]

See this

[jyothi prasad]

sir i using labview for the past one and half year.i have conducted experiments on strain gauges fixed to a beam,where the beam is fixed at one end.but here my problem is, the specimen is rotating.now tell me the ways to get strain from a rotating specimen.

[BruceAmmons]

It is possible to use strain gauges on a rotating specimen if you use slip rings to transfer the signal between the rotating and non-rotating environments.  There are also various non-contact measurement methods, such as laser measurement and vision system.  It really depends on what details you are trying to measure.  Can you describe a little better the equipment you are using and the details of what you need to measure?

Bruce

[RavensFan]

Are you MPSingh or Jyothi Prasad?  Please stick with one login name.

There are also telemetry based systems that have a transmitter mounted on the rotating part and send a signal out using radio waves.  But they may be too big for your specimen, and they are also expensive on the order of thousands of dollars.

[jyothi prasad]

sir

if i get strain signal from the specimen then i can use labview fatigue analysis tool kit.slip rings is not a possible solution because it arrests the propagation of crack

[jyothi prasad]

sir

can u tell me the ways of acquiring strain from a rotating specimen with moderate cost.

[BruceAmmons]

Can you describe what you are trying to do?  What size and shape is the sample?  What kind of strain are you trying to measure?  Are you trying to measure strain at a single point or all over?  Do you just want to know how much the whole bar is bending?

We can't help you if you don't give us enough information to work with.  Right now all we know is that it is rotating very fast.  Repeating your question over and over again doesn't help.

Bruce