Dynamic elastic modulus E and damping ratio zeta measurement method for timber wood and wooden composite material

Abstract

The invention relates to a method used for measuring the dynamic elastic modulus epsilon and damp ratio xi of woods and wooden compound materials. An acceleration sensor is adopted to convert the inherent mechanical quantity (acceleration) into electric signals and then the data is collected to measure the basic frequency f1 of cantilever beam material with the focused quality after the wave filter and amplification by a signal regulating instrument; the material dynamic elastic modulus epsilon dynamic is figured out in virtue of the defined relation between the material elastic modulus and the basic frequency f1 actually measured by a frequency-domain plot. The amplitudes of A1, A2, ellipsis and An are read out on the time-domain attenuating surge curve in the time-domain plot and then the logarithmic decrement delta and damp ratio xi are respectively figured out. The invention has the advantages that the actual dynamic changes of woods and wooden compound materials can be objectively reflected; the dynamic elastic modulus epsilon and damp ratio xi of woods and wooden compound materials can be simultaneously figured out and the measuring time is short and the data is full, accurate and reliable; and the basic frequency (f1) and damp features can be obtained in the frequency-domain plot and time-domain plot of the measured samples for the relevant analysis.

Description

technical field [0001] The invention relates to a method for measuring dynamic elastic modulus E and damping ratio ξ of wood and wood composite materials. The utility model belongs to the technical field of measuring wood and wood composite materials. Background technique [0002] In the field of material testing in the wood industry, in order to reflect the deformation and other characteristics of wood and wood composite materials, only the static elastic modulus E is measured at present, which cannot objectively reflect the dynamic deformation of materials under actual conditions. Therefore, the measurement of wood and wood composite materials The dynamic elastic modulus value E and the damping ratio ξ and other work become inevitable. Contents of the invention [0003] The purpose of the present invention is to use the dynamic signal random excitation power spectrum vibration measurement method to measure the dynamic elastic modulus value E and the damping ratio ξ thro...

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Problems solved by technology

[0002] In the field of material testing in the wood industry, in order to reflect the deformation and other characteristics of wood and wood composite materials, only the static elastic modulus E is measured at present, which cannot obj...

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