文献类型：期刊文献

英文题名：Fracture mechanisms of softwood under longitudinal tensile load at the cell wall scale

作者：Wang, Dong[1,3] Lin, Lanying[1,2] Fu, Feng[1] Fan, Mizi[2]

第一作者：Wang, Dong

通信作者：Lin, LY[1];Lin, LY[2]

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China;[2]Brunel Univ, Coll Engn Design & Phys Sci, Uxbridge UB8 3PH, Middx, England;[3]Nanjing Forestry Univ Mat & Sci & Engn, Nanjing 210037, Peoples R China

年份：2020

卷号：74

期号：7

起止页码：715-724

外文期刊名：HOLZFORSCHUNG

收录：;EI(收录号：20203209030059);Scopus(收录号：2-s2.0-85082739601);WOS:【SCI-EXPANDED(收录号:WOS:000552030600008)】；

基金：The authors gratefully acknowledge the financial support of the Nature Science Foundation of China (no. 31770597) and the program from the China Scholarship Council (no. 201803270009).

语种：英文

外文关键词：crack propagation; fracture initiation; longitudinal tensile load; softwood

摘要：This study was undertaken to elucidate the longitudinal tensile fracture behaviors of softwood at the cell wall scale by means of microscopic analyses. The fracture types of the tracheids at the different fracture surfaces were also distinguished. The results indicated that the main tracheid fracture of the earlywood (EW) sample was transverse transwall breakage. The tracheid fracture process of the transverse transwall breakage was initiated as a fracture in the S-2 layer, with the crack propagating into the S-1/S(2 )interface. For the EW/latewood (LW) sample, the strain concentration and initial crack under longitudinal tensile load generally occurred in wood rays in the EW part, which caused the tracheids to experience transverse transwall breakage. The differences in longitudinal and transverse strains between EW and LW under longitudinal tensile load led to shear stress and parallel-to-grain cracks occurring at the growth ring border. When the crack propagated along the wood grain in the EW tissue or growth ring boundary, this resulted in EW longitudinal transwall breakage. However, when the crack propagates along the wood grain in the LW tissue, it could cause the LW tracheid to undergo intrawall breakage, with the crack occurring predominantly at the compound middle lamella (CML)/S-1 interface region.