LMSD 2021 Dataset for Damage Identification in Plates

<h1>LMSD 2021 Dataset for Damage Identification in Plates</h1> <p>These files contain data collected to experimentally validate damage identification methods for plate-like structures.</p> <h2>Experimental Setup</h2> <p>The inspected structure is a 600mm x 600mm x 4mm CFRP plate with crossply layup. A 12 x 12 square grid of 144 nodes is defined on this plate, with 50mm spacing and 25mm offset from the edges of the plate. The plate is hung with elastic bands to obtain free-free boundary conditions. It is excited on its front-side with a PCB 086C03 impact hammer. 7 PCB 352a24 1D-accelerometers are installed on its back-side.</p> <p>Additional masses are glued to the plate to reproduce the scattering effect of damage. Two types of scenarios are considered: point-like masses of 55g at pre-defined nodes on the grid and an elongated mass of 315g covering several nodes. A total of 6 damage scenarios are considered, 5 point-like scenarios with 1, 3, 4, 5 and 6 added masses, respectively, and 1 elongated-mass scenario with 1 added mass.</p> <p>The included pictures summarize the experimental setup and show the 12 x 12 grid of nodes with the position of the 7 accelerometers/hammer impact locations in black and the positions of the added masses in red (the number labels at a given position indicate which scenarios have a mass added at that position). Zoomed views are also provided of a 55g point-mass and a 315g elongated mass, glued to the plate.</p> <h2>Data Acquisition Procedure</h2> <p>To obtain the baseline FRFs, the responses are measured on the healthy plate from all 144 nodes to the 7 accelerometer nodes. To obtain the damaged FRFs, the responses are measured on the damaged plate from the 7 accelerometer nodes to the 7 accelerometer nodes. The resulting damaged responses form what is also referred to as the multistatic data matrix. Each measurement is repeated 5 times and the responses are averaged to increase the SNR. The measured FRFs consist of 8192 frequency bins between 0Hz and 1600Hz.</p> <h2>Data Structure and Organization</h2> <p>The baseline file contains: <ul> <li>frf 7x144x8192 double: baseline frf from all 144 nodes to the 7 accelerometer nodes. <li>frequency 1x8192 double [Hz]: the frequencies in Hertz. <li>node_position 144x2 double [mm]: position of the nodes in millimeters. <li>probing_nodes 1x7 uint16: indices of the accelerometer nodes, which are also the nodes that receive hammer excitation to collect the damaged responses. </ul> </p> <p>Each damage scenario is associated to a file with a corresponding, descriptive filename. Each of the files contains: <ul> <li> frf 7x7x8192 double: damaged frf from the 7 accelerometer nodes to the 7 accelerometer nodes (also referred to as multistatic data matrix). By convention, frf(i, j, :) is the frf measured at accelerometer i when a hammer excitation is applied at the location of accelerometer j. <li>mass_nodes 1xn uint16: indices of the nodes at which a mass is added. </ul> </p> <p>The datasets are provided both as mat files and npz files, alongside with helper functions to conveniently load the data and accelerate collaboration. Note that the mat files use MATLAB-compatible indexing (i.e. node numbering starts at 1) while the npz files use conventional zero-based indexing (i.e. node numbering starts at 0). For this reason all node indices in the probing_nodes and mass_nodes variables are offset by one in the mat files compared to the npz files.</p> <p>Helper functions and examples demonstrating how to load and process the data are provided alongside this dataset under MIT Licensing.</p> <h2>Licensing</h2> <p>Data produced and made available by the LMSD group, KU Leuven, under CC BY 4.0 Licensing.<br> Code written by Nathan Dwek with the LMSD group, KU Leuven, made available under MIT Licensing.</p> <h2>Citing this Work</h2> <p>If you use the data itself directly, please cite this dataset appropriately. Proper citation text can be found on the dataset webpage in multiple formats.</p> <p>Please cite the relevant publication(s) below if your work is based on or compares to the damage identification methods they introduce: <ul> <li>N. Dwek, V. Dimopoulos, D. Janssens, M. Kirchner, E. Deckers, and F. Naets, "Damage Identification in Plate-Like Structures Using Frequency-Coupled L1-Based Sparse Estimation," (Pre-print submitted to MSSP, October 31, 2023). Available at <a href="https://ssrn.com/abstract=4644311">SSRN</a>. doi: <a href="https://doi.org/10.2139/ssrn.4644311">10.2139/ssrn.4644311</a> <li>N. Dwek, D. Janssens, M. Kirchner, and E. Deckers, "Sparse Damage Identification at Off-Grid Locations on Plate-like Structures using Frequency-Coupled Group Lasso," to be presented at the 2024 European Workshop on Structural Health Monitoring, June 2024. </ul> </p> <h2>Contact</h2> <p>Nathan Dwek - <a href="mailto:[e-mail]">[e-mail]</a><br> LMSD Group - <a href="mailto:[e-mail]">[e-mail]</a><br> Department of Mechanical Engineering<br> KU Leuven<br> Belgium </p>LMSD 2021板材损伤识别数据集 本数据集包含用于实验验证板状结构损伤识别方法的实测数据。 ## 实验装置 本次测试的结构为一块尺寸600mm×600mm×4mm的交叉铺层碳纤维增强聚合物（Carbon Fiber Reinforced Polymer, CFRP）板材。该板材上布设了12×12的方形网格，共计144个测点节点，节点间距为50mm，且与板材边缘的偏移量为25mm。使用弹性吊绳悬挂该板材，以实现自由-自由边界条件。在板材正面采用PCB 086C03型冲击锤进行激励，在板材背面安装7个PCB 352a24型一维加速度传感器。 通过在板材上粘贴附加质量块来模拟损伤的散射效应。本次实验共设置两类损伤工况：一类为在网格预设节点上粘贴55g的点状质量块，另一类为粘贴覆盖多个节点的315g长条状质量块。总计6种损伤工况，其中5种为点状质量工况，分别粘贴1、3、4、5、6个质量块，剩余1种为长条状质量工况，粘贴1个长条质量块。 数据集附带的图片汇总了实验装置布局，展示了12×12的测点网格：7个加速度传感器/锤击激励点的位置以黑色标注，附加质量块的位置以红色标注（某一位置的数字标签代表在该位置粘贴质量块的工况编号）。此外还提供了粘贴于板材上的55g点状质量块与315g长条质量块的放大视图。 ## 数据采集流程 为获取基准频响函数（Frequency Response Function, FRF），在无损伤的健康板材上，采集所有144个测点节点至7个加速度传感器节点的响应信号。为获取损伤工况下的FRF，在带损伤的板材上，采集7个加速度传感器节点之间的响应信号，所得的损伤响应数据也被称为多静态数据矩阵。每次测量重复5次，对响应信号取平均以提升信噪比（Signal-to-Noise Ratio, SNR）。所采集的FRF包含0Hz至1600Hz范围内的8192个频率分段。 ## 数据结构与组织 基准文件包含以下内容： - frf：7×144×8192的双精度数组，为所有144个测点节点至7个加速度传感器节点的基准频响函数。 - frequency：1×8192的双精度数组，单位为赫兹（Hz），存储各频率点的数值。 - node_position：144×2的双精度数组，单位为毫米（mm），存储各测点节点的平面坐标。 - probing_nodes：1×7的无符号16位整型数组，存储加速度传感器节点的索引，同时也是用于锤击激励以采集损伤工况响应的测点节点。 每种损伤工况对应一个带有描述性命名的文件，各文件包含以下内容： - frf：7×7×8192的双精度数组，为7个加速度传感器节点之间的损伤频响函数（即前述的多静态数据矩阵）。按照惯例，frf(i, j, :)代表在加速度传感器j的位置施加锤击激励时，于加速度传感器i处测得的频响函数。 - mass_nodes：1×n的无符号16位整型数组，存储粘贴质量块的测点节点索引。 本数据集同时提供mat格式与npz格式的数据文件，并附带便捷的数据加载辅助函数以促进协作。请注意，mat文件采用MATLAB兼容的索引规则（即节点编号从1开始），而npz文件采用常规的从零开始的索引规则（即节点编号从0开始）。因此，probing_nodes与mass_nodes变量中的节点索引，在mat文件中相较于npz文件会偏移1个单位。 本数据集附带了用于演示数据加载与处理方法的辅助函数与示例代码，采用MIT许可协议进行发布。 ## 许可协议 本数据集由比利时鲁汶大学（KU Leuven）LMSD研究团队制作并发布，采用CC BY 4.0许可协议。由Nathan Dwek与LMSD研究团队编写的代码采用MIT许可协议发布。 ## 引用说明 若直接使用本数据集，请按照规范进行引用。规范的引用文本可在数据集网页上以多种格式获取。 若您的研究基于或对比了本数据集提出的损伤识别方法，请引用以下相关文献： - N. Dwek、V. Dimopoulos、D. Janssens、M. Kirchner、E. Deckers与F. Naets，《基于频域耦合L1稀疏估计的板状结构损伤识别》，（2023年10月31日提交至MSSP的预印本），可在SSRN获取，DOI：10.2139/ssrn.4644311 - N. Dwek、D. Janssens、M. Kirchner与E. Deckers，《基于频域耦合组Lasso的板状结构非网格测点稀疏损伤识别》，将在2024年6月举办的2024欧洲结构健康监测研讨会上发表。 ## 联系方式 联系人：Nathan Dwek，邮箱：[e-mail] LMSD研究团队，邮箱：[e-mail] 机械工程系 鲁汶大学（KU Leuven） 比利时

搜集汇总

背景与挑战

背景概述

该数据集是一个用于板状结构损伤识别方法验证的实验数据集，包含一个CFRP板上144个节点网格的健康状态和6种损伤场景（点状和伸长质量）的频率响应函数测量。数据以高分辨率频率响应（8192个频率点，0-1600Hz）形式提供，包括基线数据和损伤数据矩阵，支持MAT和NPZ格式，并附带辅助代码。数据集旨在促进结构健康监测和逆问题研究，适用于损伤检测算法开发和验证。