User can use the electro-magnetic induction to make the steel chord vibrate. Then observing the standing wave by oscilloscope research on the function relationship between chord length, tension, linear density and driving frequency.
1. Observing the standing wave
2. Research on the function relationship between chord length, tension, linear density and driving frequency.
1. Different linear density kinds of steel chords are provided, such us Φ0.4mm, Φ0.3mm, Φ0.5mm, all for 2 pieces.
2. Dedicated signal source has a low output impedance. It can use low impedance driving sensor to generate excitation signals. At the same time, the degree of regulation and resolution of frequency is small enough so that it can easily find the resonant frequency.
Typical experimental context and data
1. Verify the relationship between the wavelength of shear waves and tension of chords.
Table 1. relations in fixed frequency
Note: frequency of vibration wave source f = 100.00Hz, m is the mass of weights and rider hock, L is the length of chord of standing wave, n is the half wave number in L length(note: the number n depends on linear density of the chosen chord.
By the least square method, the log λ ~ log T slope is K = 0.4984, coefficient of association: r = 0.9988
2.Verify the relation between the wavelength of shear waves and vibrational frequency of wave source.
The total mass of weights and pothook m = 150.00 x 10-3kg, the acceleration of gravity in Hangzhou: g=9.793m/s2 Tension T = 150.00 x 10-3 x 9.793 = 1.469N. The result is show below:
By the least square method, the log λ ~ log T slope is K =0.9847, coefficient of association: r = 0.9979
3. Verify the relation between the wavelength of shear waves and density of chord.
The real experiment. Experimental condition: position of mounting plate: 10, 70cm, length of chord 60cm
String Vibration Experiment with Independent Signal Generator
String Vibration Experiment with Integrated Signal Generator