基于聲發(fā)射信號多重分形特征的櫸木損傷斷裂過程

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中圖分類號：S781.2；S781.38 文獻標(biāo)識碼：A DOI：10.7525/j.issn.1006-8023.2025.04.013

Abstract：Aiming at the acoustic emission （acoustic emission，AE）signals emitted from wood damage and fracture pro cess，multifractal detrended fluctuationanalysis（multifractaldetrendedfluctuationanalysis，MF-DFA）wasused toextractthecharacteristicparametersoftheAEsignals，andthentostudythefractalcharacteristicsofthe micro-and macrodamage behaviorsof wood.First，theAE signals generatedduring thethree-pointbending testof Zelkovaschneideriana specimen were collected.Then，the AE signal were intercepted bya sliding time windowand treated as a sequence of time periods. The generalized Hurst index，spectral width Δα ，singularity index αmax and αmax were calculated according to the MF-DFA method todescribe thelong-rangecorelationandtime-varying multifractal characteristicsof the AE signal.Finally，the whole process was categorized into elastic，elastoplastic and plastic stages based on the trend of Δα The results showedthattheAEsignalreleasedbythefracture processhadlong-rangecorrelationand its fluctuation was a multifractal process. And the value of αmax in the elastic stage was greatly reduced，which meant the multi-source charac teristics in the early stage of failure；the change of elastic-plastic stage αmax in a small range showed that the specimen hadacertain stiffess；the macroscopic fracture behaviorcan be predictedbythe time when the plastic stage αmin dropped suddenly.

Keywords：Wood；acoustic emission；multifractal；detrended fluctuation analysis

0 引言

木材作為一種具有多孔層狀結(jié)構(gòu)的生物復(fù)合材料，其特殊的纖維結(jié)構(gòu)使其容易產(chǎn)生復(fù)雜的斷裂機制和內(nèi)部損傷，因此木質(zhì)材料在長期使用過程中的安全監(jiān)測是非常重要的。（剩余15378字）