METHOD OF DETERMINING DAMPING CHARACTERISTICS OF MULTILAYER DEVICES DURING IMPACT ACTION Russian patent published in 2009 - IPC G01M7/08 

FIELD: physics.

SUBSTANCE: present invention relates to impact testing and can be used mainly in high-intensity impact tests for various devices, comprising multilayer devices in form of, for example stacks of plates made from composite materials, honeycomb panels etc. The method of determining damping characteristics of multilayer devices during impact action involves applying impact action on the test device using a pyrotechnic device, measuring momentum and determining dynamic reaction of the test device using accelerometres and strain sensors. The strain wave is first generated in a waveguide without the test object. After that by analysing amplitude spectra and shock spectra of accelerations, a conclusion can be made on damping characteristics of the multilayer device. A damping model is made first from material of the layers of the multilayer device. Impact action is then generated in the waveguide without the test object, while measuring amplitude of shocks from the minimum, produced by the test equipment, to the maximum operating levels. Further, the multilayer device is then tested in several stages, loading one its layers on each stage. Amplitude of shocks on each stage is varied from minimum values, produced by the test equipment, to maximum operational levels, after which the direction of the impact action on the multilayer device is changed to the opposite and all stages of testing the multilayer device are repeated. By analysing the vibration record and strain record, amplitude spectra and shock spectra of accelerations, the damping model of material of the layers of the multilayer devices and the device as a whole is applied using a given formula.

EFFECT: increased accuracy of determining damping mechanism and its numerical characteristics.

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