基于声发射临界慢化特征的木材断裂前兆

打开文本图片集

关键词：木材；声发射；b值；微观破坏；宏观破坏；临界慢化；前兆预测；屈服强度 中图分类号：S781.5；S781.38 文献标识码：A DOI：10.7525/j.issn.1006-8023.2026.01.008

Wood Fracture Precursors Based on Critical Slowing Down CharacteristicsofAcousticEmission

ZHAI Erzhuang1，LI Ming 2，3* ，FANG Saiyin1*，DENG Tingting1，CHEN Chumin1，WANG Jinggui 1 ， DU Kun1 （1.SchoolofacineryandTrasporatio，outhwestForestryUnversityKunmng504China；.KeyLabratoryofdaced PerceptionandIntelligentControlofHig-endEquipment，MinistryofEducation，AnhuiPolytechnic University，Wuhu241000， China;3.Schoolof Electrical Engineering，AnhuiPolytechnic University，Wuhu 2410OO，China）

Abstract：To predictthe micro and macro failurebehavior of wood under load，a prediction approach of wood damage precursors based ontheb-value（describe the frequency distribution characteristics ofacoustic emision signals）of the acoustic emission（AE）signalandthe critical slowing down（CSD）characteristics was proposed.Firstly，to analyze the impact ofload application rate on the wood failure process，two loading rates of 2 mm/min and 5 mm/min were employed inthe wood thre-point bending experiment，andAE signals released during the damage processof wood specimens were collected at a sampling rate of 500kHz . Subsequently，an improved b-value calculation approach based on the classificationof AE signal amplitude was proposed，andthe AE signals generated during the experiment were divided into three levels，and the processof crack generation and development inside the wood specimen underload was described accordingly.Finally，in accordance with the principle of CSD，a prediction method of wood fracture precursors based on the length corelationcoeffcientand varianceofAEsignalwaspresented.Theresults demonstratedthatthecombinationof diffrentlevelsofb-values canreflectthefracturefeaturesandthegenerationof microcracks inthedamage process of the specimen.CSDoccurred when wood crackedatboththe microand macro levels，which was manifestedintheincreaseof thecorrelation coefficientand variance of AE signal.Atdiferent loading rates，when theload reached approximately80% of the ultimate yield strength，allthe specimens displayed a significant CSD phenomenon. Keywords：Wood;acoustic emission；b-value；microscopic destruction；macroscopic destruction；critical slowing down;precursor prediction； yield strength

0 引言

木材作为一种绿色环保的可再生材料，被广泛用于建筑结构中。（剩余14574字）