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本帖最后由 westrongmc 于 2013-1-9 21:34 编辑
下面是2011年国际模态会议的模态参数辨识竞赛(Round Robin)数据,
你有兴趣挑战一下吗?请点击下面的链接,可以下载数据。大家可以展示一下自己的分析结果,相互比对一下。
提醒的是:这个竞赛早已经结束,请不要给主办方发信了。
第1个链接:试验模态分析情形:
http://www.me.mtu.edu/imac_mpe/
SEM Modal Analysis Technical Division presents
Modal Parameter Estimation Round RobinIMAC XXIX 2011
Jacksonville, FL
Modal parameter estimation (MPE) is a common activity for experimental structural dynamicists. Many MPE algorithms are documented and compared in the history of the IMAC proceedings. MPE is the final step to determine the modal parameters for a particular structure under test. MPE is calculation intensive and several commercial and custom software tools exist to automate the calculations and guide users through the MPE process. The purpose of the Modal Parameter Estimation Round Robin is to compare MPE results from a wide range of participants using various commercial and custom implementations of MPE algorithms. To ensure consistency, the same data sets will be available to each participant. The organizers will then collect and compare results. At a special session of IMAC 28, participants will have the opportunity to present their work, and the organizers will present a comparison of results. Each standard data set will contain: - Numeric Data (Universal File Format)
- Single or multiple reference frequency response functions (FRFs)
- Corresponding ordinary coherence functions
- Geometry information (point identification and 3-D coordinates, connectivity)
- Descriptive Information
- Boundary condition(s)
- Excitation technique
- Data acquisition conditions and parameters
The organizers request that the participants provide: - Numeric Results
- Scaled mode shapes, natural frequencies, and damping information (UFF type 55)
- Synthesized FRFs for the measurement DOFs included in the original data set (SDF or UFF type 58)
- Descriptive Results
- Software used
- MPE algorithm(s) used
- General comments about the user confidence in the results
The organizers will compare the submitted results using several methods: - Modal Assurance Criteria (MAC) to establish mode correspondence
- Statistics of natural frequencies for corresponding mode shapes
- Statistics of damping values for corresponding mode shapes
- Comparison of synthesized FRFs
- Individual
- Multivariate Mode Indicator Function (MIF)
- Sum of the square amplitude
Several data sets are available on the Michigan Technological University web site ( www.me.mtu.edu/imac_mpe). Participants are required to submit MPE results for the calibration data sets, to identify any overall scaling bias. Users can then choose from any combination of the other data sets. Description of available data sets: Click on a each link set for a description of the data and download information.
=============================== 第2个链接:响应模态参数辨识情形:
SEM Modal Analysis Technical Division presents
Output Only Modal Parameter Estimation Round RobinIMAC XXIX 2011 Jacksonville, FL
Organized By: Dr. Shashank Chauhan, Research Engineer, Bruel & Kjaer Sound and Vibration
Last year at IMAC XXVIII 2010, the Round Robin exercise concerned with estimation of modal parameters in traditional experimental modal analysis framework where information of input excitation forces is also available along with output responses. Typically, the information about excitation forces and corresponding output responses is processed to obtain frequency response functions which are then utilized for modal parameter estimation purposes.
The goal of this year’s round robin is to estimate modal parameters in the framework of Operational Modal Analysis, OMA. Operational modal analysis differs from traditional experimental modal analysis in that it only requires information of the output responses and modal parameters are estimated only the basis of this information. OMA presents several advantages including the availability of modal parameters of structure in operation thus representing a closer picture of the structure and its boundary conditions (which are not that easy to realize in laboratory conditions). However, lack of input excitation force information presents several challenges as well, e.g. rigorous signal processing is needed to deal with low Signal-to-Noise ratio, proper estimation of damping, estimation of modal parameters in presence of harmonic excitation, etc. OMA modal parameter estimation algorithms range from simple Single Degree of Freedom (SDOF) peak picking methods to modifications of existing traditional modal parameter estimation algorithms and state space model based algorithms, such as Stochastic Subspace Identification (SSI) algorithm. The purpose of the Output-Only Modal Parameter Estimation Round Robin is to compare modal parameters estimated by various participants (using commercially available and custom made OMA algorithms). It is expected that this study will help in better understanding of OMA algorithms and associated signal processing techniques, and aid in their overall application to various real life structures. Four different datasets, an analytical example, an experimental structure and two real-life structures, are chosen for this exercise. For consistency, the datasets are presented in terms of raw time histories. The participants are free to process the raw time histories using signal processing techniques of their choice before estimating the modal parameters. Details of the characteristic information provided by various datasets is as follows - Raw time histories as .mat files (Matlab format) as well as in universal file format,
- Geometry information (point identification and 3-D coordinates, connectivity),
- Descriptive Information of the system,
- Data acquisition conditions and parameters
For comparing the results, participants are requested to submit the following - Natural Frequencies (in Hz), Damping (in % critical),
- Unscaled Mode Shapes,
- Description of Signal processing used, for e.g.
- Time or Frequency domain
- Block size, Window used, Number of Averages and Percent Overlap used
- Other Techniques like Cyclic Averaging
- Modal parameter estimation algorithm used,
- Software used,
- General comments about the user confidence in the results,
- Descriptive Results
The organizers will compare the submitted results using several methods: - Modal Assurance Criteria (MAC) to establish mode correspondence
- Statistics of natural frequencies for corresponding mode shapes
- Statistics of damping values for corresponding mode shapes
At a special session of IMAC XXIX, participants will have the opportunity to present their work, and the organizers will present a comparison of results. Several data sets are available on the Michigan Technological University web site ( www.me.mtu.edu/imac_oma). Users are kindly asked to analyze various data sets since they together represent the diversity normally encountered in OMA applications. The data sets along with their respective description can be downloaded at following links. - Analytical Datasets
- Calibration Datasets (General Moderately Damped System)
- Calibration Datasets (General Lightly Damped System)
- Calibration Datasets (Proportional Heavily Damped System)
- Lab based setup
- Scaled Model of a Wind Turbine Blade
- Real Life Cases Studies
Plan View of Erfttal Brifge
Measurement Locations
Ship Structure
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