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The DrDAQ USB data logger includes a microphone, A-to-D converter, and spectrum analysis software, for about £120. It should give you a reasonable response up to 20 kHz.
Free audio software called Audacity will show frequency-analyses.
How would you measure the natural resonance of concrete cube ?Supposing I had a cube of 10 x 10 cm, cast from normal concrete,suspended in air by two springs, or perhaps laying on a flat surface ?How would you go about of obtaining the cube's natural resonance frequency, on a shoe string budget ?
If we now stretch our imagination a little further, and instead looking atsomething like a big jet engine, could the same technique be applied todefine by experiment the natural resonance of the jet engine ?
Quote from: homebrewer on 26/11/2013 13:30:36How would you measure the natural resonance of concrete cube ?Supposing I had a cube of 10 x 10 cm, cast from normal concrete,suspended in air by two springs, or perhaps laying on a flat surface ?How would you go about of obtaining the cube's natural resonance frequency, on a shoe string budget ?dangling on a shoe-string would be better than on springs, otherwise you'll get the resonant frequency of the springs. You may get different resonant frequencies from the block depending on where you hit it due to different modes of vibration.http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/sounds-from-a-mug/
A block on a spring in tension has a resonance too.You have just suggested that stringed instruments are impossible.
Quote from: Bored chemist on 27/11/2013 14:46:30A block on a spring in tension has a resonance too.You have just suggested that stringed instruments are impossible.OK how about shoving & dragging the 10cm concrete block across various-sized paving-stones* with various things, sticks, string, hands ...[attachment=18253] [ the parallel horizontal lines on the spectrogram above are the resonant frequencies + their harmonics ]http://www.freesound.org/people/thanvannispen/sounds/29987/and only use the frequencies common to both shoving and dragging on all the paving stones as resonant frequencies for the block. [* maybe add a pinch of fine gravel ]
Out of interest, could you clarify the link between the question about concrete resonances and sonotrodes, please? Thanks for your interest, I have replied to the forum a little bit further down.
Quote from: Bored chemist on 27/11/2013 14:46:30Its truly an amazing technology..... thanking you.
Its truly an amazing technology..... thanking you.
... And here I will start with my experiments with a concrete cube ...I see a propability for the application of new fracking techniques employing sonochemistryto extract all methan gas in a single application, with fewer chemicals and lesser environmentalburdens and higher yields.
Quote from: homebrewer on 14/12/2013 23:56:46... And here I will start with my experiments with a concrete cube ...Thank you for your image, great to underpin your argument. But I like to study the "Natural Resonance Frequency" of materialsand complex assemblies at random.A Russian Professor ZP Shulmann inspired me from an article written in the late 1990 tees, published in the : "Journal of Non-Newtonian Fluid Mechanics - Elsevier"in which Prof. Shulmann undertook "Natural Resonance Research", andpostulated research on large structures from "drilling rigs" to "space rockets"using electro-rheological actuators.Now in 2013 the ESA, just finished a massive shaker to test "satellites".Sadly to say, Britain has lost it's role as a space Nation, but the UK governmentspends millions of pounds to support Chinese and Indian space research. Towhat avail ?What will the future be for highly skilled UK researchers and technicians ?Only opportunities to watch the UK stepping into technical oblivion ?
... And here I will start with my experiments with a concrete cube ...