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Recent content by CaptainCrunch

  1. CaptainCrunch

    Test measurement of torque pulse on tractor engine

    I've been asked to measure torsional vibration due to the torque pulse of a two cylinder engine on a tractor. The idea is to isolate the effect of torque pulse and determine the effectiveness of a torsional damper in reducing this effect. I'm visualizing the accelerometers 180 degrees apartand...
  2. CaptainCrunch

    Using shaker table to verify dynamic frequency based strain

    Tha shaker will be driven with a low amplitude sign sweep. Say 5 -400 Hz at 0.1 g, sweep rate of 0.2 Hz / sec. I will be looking at all frequencies in this range (resonant and non-resonant). At each of these frequencies the displacement will be given by the accelerometer and be used to calculate...
  3. CaptainCrunch

    Using shaker table to verify dynamic frequency based strain

    I purchased an IOTech strain book with the intent of measuring strain of components on a shaker table (3300 lbf single axis TIRA )and on lawn and garden applications during normal usage. This would be used to verify that the shaker was replicating the strain levels seen in the field. Once the...
  4. CaptainCrunch

    combining single-axis vibration on angled fixtures

    Hello all, Read through an archive thread (thread384-6080) on putting components on angled fixtures (oriented in the vector sum direction) to simulate three directional vibration on a single axis shaker. Currently this is the preffered way of testing components where I work. The benefit is...
  5. CaptainCrunch

    MotionView as a Pre-Processor for MSC.ADAMS

    Hello, I am currently comparing MSC.ADAMS pre and post processors. I sat in a presentation from Altair about using MotionView as a pre and post processor for ADAMS, instead of using what you get with the software, ADAMS VIEW. Some Questions: Does anyone have experience with both packages...
  6. CaptainCrunch

    Simulating thrre directional vibration on a one-directional shaker

    Hello All, I was hoping to get some thoughts on simulating three directional vibration on a one-directional shaker. I am running small engines (3-30 Hp, one to three cylinder) and engine components (mufflers, air cleaners, carberateurs, etc.) on 3500 lbf TIRA shaker. Generally I test 4-20...
  7. CaptainCrunch

    How to reproduce very low frequency vibration on shaker table

    Hello All, I have a tamper application that experiences very high amplitude, very low frequency vibration (e.g. 20g @ 0-3 Hz) when tamping a hard surface. Normally to reproduce field data on the shaker I exclude the 0-10 Hz vibration data and run 10-800 Hz, the range of structurally damaging...
  8. CaptainCrunch

    Accelerated Vibe Testing: "Focused Simulation" Paper from Dennis Young

    Hello All, Lately been thinking about accelerated testing. There was an article in TEST magazine by William Kipp who references two papers I am trying to track down: 1. "Focused Simulation" 1993, Dennis Young 2. "Selection and Performance of Vibration Tests", 1971, by...
  9. CaptainCrunch

    FEA of fuel tank vibration with fuel in tank

    Greg, Thanks. I am also concerned with coupling opposite walls of a fuel tank with some type of spring element. I cross-posted this to the FEA group and some were recommending using spring elements from the walls to the fuel cg with a mass element at the cg. Then they reccomended tuning the...
  10. CaptainCrunch

    FEA of fuel tank vibration with fuel in tank

    Hello, I am thinking of ways to run a FEA vibration analysis of a fuel tank full of fuel. Actually I want ot examine the bracket which supports the tank and I think the fuel in the tank will make a significant differnence. My problem is how to simulate the mass of the fuel in a tank, but have...
  11. CaptainCrunch

    FEA of fuel tank vibration with fuel in tank

    Hello, I am thinking of ways to run a FEA vibration analysis of a fuel tank full of fuel. Actually I want ot examine the bracket which supports the tank and I think the fuel in the tank will make a significant differnence. My problem is how to simulate the mass of the fuel in a tank, but have...
  12. CaptainCrunch

    Hand-arm vibration ANSI spec for lawn mowers

    Hello, Does anyone have an electronic copy of ANSI spec B175.3-1997 they could send me? Also, does anyone know the recommended limit of ANSI weighted hand values? Some of the technicians I work with say the limit is 5.0 m/s^2 but I'd like to confirm that. Thanks in advance, George V.
  13. CaptainCrunch

    FEA of Wobble in bent crank shaft of lawn mower

    Brad, I think a modal based implicit dynamic analysis may be the ticket with this problem. I have ABAQUS/Standard available to me. I have done numerous mode based steady state dynamic problems so I am familiar with the pros and cons. In theory I could output the nodal displacements from...
  14. CaptainCrunch

    FEA of Wobble in bent crank shaft of lawn mower

    Greg, I think I see where your going, a static modal with force input which represents the eccentirc loading (could be determined by a mix of fea and hand calcs.). But what I am trying to do is model this as a dynamic event (i.e. a time history) not as a modal (i.e. steady state dynamic). I may...
  15. CaptainCrunch

    FEA of Wobble in bent crank shaft of lawn mower

    Hello All, Any body have any ideas on how to analyse wobble of a mower with a bent blade and bent crankshaft USING FINITE ELEMENT ANALYSIS? I know how to do the test, and here is an example of were testing would be much easier than FEA. But say you had to do this in FEA, any ideas on the...

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