Resonance testing

O HARDENED SLEEVES UNDER BEARINGS (5.3.10.7) O RESONANCE TEST (5.3.S.2)... 

Optional tests data and reports include NPSHR test, complete unit test, sound level test, auxiliary equipment test, bearing housing resonance test, and any other tests mutually agreed upon by the purchaser and vendor. 

S.2 be provided) Is a resonance test required for vertically suspended pumps Yes No... 

A459 Vertical pump resonance test V RES TEST C 1 1 ryes (true) Or no (ftilse)... 

AS36 Bearing housing resonance test BRG HOUS c 1 Ainon witnessed Biwitnessed Ciobserved Di none Ziother... 

If a resonance test is specified, the bearing housing(s) shali be excited by impact or other suitabie means with the pump unpiped and the naturai frequency(ies) shaii be determined from the response. A separation margin shaii exist between the naturai frequency(ies) and the foiiowing excitation frequencies. 

The results of dynamic tests are dependent on the test conditions test piece shape, mode of deformation, strain amplitude, strain history, frequency and temperature. ISO 4664 gives a good summary of basic factors affecting the choice of test method. Forced vibration, non-resonant tests in simple shear using a sinusoidal waveform are generally preferred for design data as... 

When considering the bending of a beam and attempting to extract a modulus value one must make several assumptions, the most important being that the modulus in tension is the same as in compression, and is independent of strain (at least for the range of strain involved). The simple Bernoulli-Euler theory is usually used to interpret the data. When performing resonance tests it is particularly useful to find a set of resonances and compare the measured frequency ratios with the theoretical ones given in the previous chapter. 

Dynamic properties tests on viscoelastic materials fall into the general categories of resonance tests and non-resonance tests (1). They can be further subdivided into tests using base motion excitation (2), (3) and direct force excitation (4), (5). Still another classification may be made according to whether the specimen is stressed in extension, shear, or dilatation. An important issue in the selection of test methods is whether it will... 

Fatigue tests on hybrid joints bonded with the FT-EP adhesive were also carried out, by using a tension-tension fatigue test (Croccolo et al., 2010 Sekercioglu et al., 2005) on a resonant testing machine. 

ASTM C1198 specifies a sonic resonance test for E and hence ( , for advanced ceramics. 

A different principle is used in ultrasonic resonance testing. Here, thickness vibrations are induced in the adherend/adhesive/adherend sandwich in which the two adherends eire considered to act as rigid masses while the adhesive is an almost massless spring. If the type and thickness of the metal sheets is constant, then the resonant frequency is a function of the thickness and bulk modulus of the adhesive. The well-known Fokker Bond Tester (Mark II) overcomes the difficulty of the many variables in the ultrasonic resonance test by coupling the joint to a system of well-defined resonance characteristics. Changes in the frequencies of the joint-transducer system are correlated with known defects and a calibration curve obtained. The calibration curves can then be used to establish acceptance limits which can be (and are extensively) used for quality control in production. 

A different principle is used in ultrasonic resonance testing. Here, thickness vibrations are induced in the adherend/adhesive/adherend sandwich in which the two adherends are considered to act as rigid masses while the adhesive is an almost massless spring. If the type and thickness of the metal sheets are constant, then the resonant frequency is a function of the thickness and bulk modulus of the adhesive. 

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