基于局部单元模态柔度差值的木质梁模拟缺陷检测  

Detection of simulated defects of wood beams by using the differences of local modal flexibility

作　　者：胡传双[1] 文伟[1] 周海滨[2] 云虹[1] 

机构地区：[1]华南农业大学林学院 [2]中国林业科学研究院木材工业研究所

出　　处：《北京林业大学学报》2011年第5期122-125,共4页Journal of Beijing Forestry University

基　　金：广东省财政厅项目(2008A020100013);林业公益性行业科研专项(200904016)

摘　　要：为尽早对结构和构件的最薄弱位置进行检测和评估,避免因突然破坏而导致的灾难性事故,本文通过振动测试获取了锯材的前两阶模态振型,并利用锯材损伤前后的局部模态柔度矩阵差值提出了损伤识别指标。为了验证所构建的损伤指标的有效性,通过人工切除截面质量来模拟不同损伤程度、不同损伤位置和双损伤的情景。结果表明:损伤识别指标对不同损伤程度、不同损伤位置和双损伤均能准确定位,并可对损伤轻重程度进行定性评价。To evaluate the weakest location and detect damage at the earliest possible stage to avoid the future catastrophic failure,in this study,the modal testing was performed on wood beams to generate the first two mode shapes.A novel statistical algorithm was proposed to extract the damage indicator by computing the local modal flexibility before and after damage in timbers.The different damage severities,damage locations and damage counts were simulated by removing mass from intact beams to verify the algorithm.The results show that the proposed statistical algorithm is effective and suitable to the designed damage scenarios.It is reliable to detect and locate the local damages under different severities,locations and counts.The peak values of the damage indicators computed from the first two mode shapes are sensitive to different damage severities and locations and they are also reliable to detect the multiple damages.

关 键 词：缺陷检测 木质梁 模态柔度 

分 类 号：S781.12[农业科学—木材科学与技术]