METHOD OF EVALUATION OF STRESS-DEFORMED STATE OF EASILY DEFORMED FIBER-CONTAINING COMPOSITIONS Russian patent published in 2008 - IPC G01N29/00 

FIELD: evaluation of stress-deformed state of easily deformed fiber-containing compositions.

SUBSTANCE: tested sample of composition is subject to forced oscillations. Resonant frequency of forced oscillations of tested sample is used as informative parameter. Deformation ε is measured at corresponding stress of composition σ. Functions σ=φ(ε) and E'=φ(σ) are built, where E' is conditional module of resilience functionally related to stress σ. Forced oscillations of tested sample of composition are excited in program-cycle mode with frequency belonging to range between two values of its natural frequencies, which correspond to initial and end state of relaxation process to provide visualization of oscillations by means of gate tachometer. Frequency of oscillations is registered on base of resonance by means of electro-optic converter set provided with built-in microprocessor. Data on resonant frequency of forced oscillations is transmitted to man processor and calculations are performed by means of computational unit of main processor, which calculates f_i=φ₁(E'I)_i in real scale time from corresponding functions and preset algorithm introduced in memory of that computational unit, where f_i is resonant frequency of forced oscillations of i-th shape spectrum, I is moment of inertia of material cross-section. Function σ=φ(f_i) is built and graph-trend of relaxation of stress of sample at its fixed deformation while taking σ_i=φ(E'_i).

EFFECT: improved sensitivity; higher precision of informative parameters of relaxation.

1 dwg