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1.
巫生平 《福建工程学院学报》2019,(6):532-538
基于频率的结构损伤识别结果易受外界环境温度的影响,应用具有一定的局限性,为此,引入计量经济学中处理非平稳信息的协整概念来消除温度对识别结果的影响。将结构正常运营状态下采集的数据作为训练样本,计算得到协整余量,再根据统计方法选取协整余量的控制线。监测中若频率的协整余量超过该控制线,即认为结构发生损伤。采用上述方法对某实际悬索桥进行分析,结果表明,所提出方法能有效识别悬索桥主梁、主缆和吊索的损伤,具有较好的工程应用前景。 相似文献
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INTRODUCTION Structural damage detection technique addresses the problem of how to locate and detect damage that occurred in a structure by using the observed changes of its dynamic and static characteristics. In recent years, damage assessment of structure has drawn wide attention from various engineering fields. Gen-erally, the existing approaches proposed in this area can be clarified into two major categories: the dy-namic identification methods using dynamic test data and the static … 相似文献
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INTRODUCTION Damage detection of structures is very importantfor ensuring and evaluating the safety of structuresystems during their lifetime. The approaches de-veloped in this field may be generally classified intodynamic identification approach using dynamic testdata and static identification approach using static testdata (Wang et al., 2001). The dynamic identificationapproach has been highly developed, although severalinherent drawbacks and problems handicap the fullutilization o… 相似文献
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Too many sensors and data information in structural health monitoring system raise the problem of how to realize multi-sensor information fusion. An experiment on a three-story frame structure was conducted to obtain vibration test data in 36 damage cases. A coupling neural network (NN) based on multi-sensor information fusion is proposed to achieve identification of damage occurrence, damage localization and damage quantification, respectively. First, wavelet packet transform (WPT) is used to extract features of vibration test data from structure with different damage extent. Then, data fusion is conducted by assembling feature vectors of different type sensors. Finally, three sets of coupling NN are constructed to implement decision fusion and damage identification. The results of experimental study proved the validity and feasibility of the proposed methodology. 相似文献
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针对DMC75VLinear五轴高速加工中心和Heidenhain iTNC530数控系统,提出一种后置处理算法,结合M128指令研究了刀具摆角B和工作台转角C的计算公式。利用编写的后置处理软件得到了不同零件的数控程序,已在该五轴加工中心上使用,从而验证了本研究的后置处理算法的正确性和可靠性。 相似文献
6.
降噪处理是分析结构振动信号、提取特征参数、研究损伤识别方法的基础,核独立分量分析(KICA)采用的核方法为结构振动信号的降噪处理提供了新的方法;通过对比KICA与其他算法降噪后信号的HHT边际谱,验证了KICA对低阻尼钢框架结构标准损伤模型降噪的优良性能,特别是提高了对结构安全至关重要的低频振动部分的能量估计的准确度。 相似文献
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提出了一种基于径向基神经网络预报的动态矩阵预测控制新算法，在该算法中，先用RBF神经网络辨识对象模型，同时预测对象的未来输出，然后用动态矩阵控制算法进行滚动优化和反馈校正。该方法解决了非线性、时变对象难以建模的问题，仿真结果验证了这一新型算法的可行性。 相似文献
8.
Arturo Garcia-Perez Juan P. Amezquita-Sanchez Aurelio Dominguez-Gonzalez Ramin Sedaghati Roque Osornio-Rios Rene J. Romero-Troncoso 《浙江大学学报(A卷英文版)》2013,14(9):615-630
Structural health monitoring （SHM） is a relevant topic for civil systems and involves the monitoring, data processing and interpretation to evaluate the condition of a structure, in order to detect damage. In real structures, two or more sites or types of damage can be present at the same time. It has been shown that one kind of damaged condition can interfere with the detection of another kind of damage, leading to an incorrect assessment about the structure condition. Identifying combined damage on struc- tures still represents a challenge for condition monitoring, because the reliable identification of a combined damaged condition is a difficult task. Thus, this work presents a fusion of methodologies, where a single wavelet-packet and the empirical mode decom- position （EMD） method are combined with artificial neural networks （ANNs） for the automated and online identification-location of single or multiple-combined damage in a scaled model of a five-bay truss-type structure. Results showed that the proposed methodology is very efficient and reliable for identifying and locating the three kinds of damage, as well as their combinations. Therefore, this methodology could be applied to detection-location of damage in real truss-type structures, which would help to improve the characteristics and life span of real structures. 相似文献
9.
针对服役结构状态评估问题提出了基于虚功误差估计算子的统计分析方法.首先定义虚功误差来表达实际结构与参数化分析模型之间的差别,然后采用改进的牛顿算法推导分析模型结构识别算法.为了探讨在有测量误差的情况下算法的性能,引用Monte Carlo方法模拟测量数据,对测量数据的误差与识别结果的影响进行了详细的分析比较.根据识别结果确定它的概率分布,通过假设试验对服役结构状态评估进行统计分析.最后应用双跨五层刚架结构进行了大量数值模拟,计算结果显示了所提方法的有效性. 相似文献
10.
杜思义 《重庆大学学报(英文版)》2003,2(2)
1. Introduction In the structural damage identification, the confirmation of parameters sensitive to damage is the foremost, namely to decide what parameters are to be adopted, the next is to distinguish damaged from undamaged, and to determine the position and severity of damages. For local damage, an identifying parameter should be a local quantity and accord the following 4 basic conditions: 1) it is sensitive to local damages and is a monotone function depicting the severity of structural … 相似文献
11.
麻胜兰刘昱昊张铮吴琛 《福建工程学院学报》2020,(1):40-45
考虑到基于2范数的正则化算法存在对结构识别结果过度光滑的效果,提出了基于模态振与L1正则化的损伤识别方法。以—2D简支梁有限元模型为数值算例,比较了使用不同振型数不同损伤程度对损伤识别效果的影响。数值模拟结果表明,对于多损伤工况,当损伤结构的振型数和无损结构的振型数乘积数大于6时,能较好地进行损伤定位,并能对损伤程度给出定性的描述。 相似文献
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Ground textures seriously interfere with the exact identification of grinding damage. The common nondestructive testing techniques for engineering ceramics are limited by their difficulty and cost. Therefore, this paper proposes a global image reconstruction scheme in ground texture surface using Fourier transform (FT). The lines associated with high-energy frequency components in the spectrum that represent ground texture information can be detected by Hough transform (HT), and the corresponding high-energy frequency components are set to zero. Then the spectrum image is back-transformed into the spatial domain image with inverse Fourier transform (IFT). In the reconstructed image, the main ground texture information has been removed, whereas the surface defects information is preserved. Finally, Canny edge detection is used to extract damage image in the reconstructed image. The experimental results of damage detection for the ground texture surfaces of engineering ceramics have shown that the proposed method is effective. 相似文献
14.
This paper presents a quantitative method for automatic identification of human pulse signals. The idea is to start with the extraction of characteristic parameters and then to construct the recognition model based on Bayesian networks. To identify depth, frequency and rhythm, several parameters are proposed. To distinguish the strength and shape, which cannot be represented by one or several parameters and are hard to recognize, the main time-domain feature parameters are computed based on the feature points of the pulse signal. Then the extracted parameters are taken as the input and five models for automatic pulse signal identification are constructed based on Bayesian networks. Experimental results demonstrate that the method is feasible and effective in recognizing depth, frequency, rhythm, strength and shape of pulse signals, which can be expected to facilitate the modernization of pulse diagnosis. 相似文献
15.
提出了2种非整数阶系统辨识方法——广义Levy法和加权迭代法.首先,将辨识整数阶系统的Levy法进行推广得到了适合非整数阶系统辨识的广义Levy法;然后,针对广义Levy法的不足,提出了一种加权迭代法.结果表明:对于非整数阶系统,采用所提出的方法能够得到更好的频域响应拟合;对于整数阶系统,采用该方法,运用阶数扫描仍然能找到拟合其频域响应的最好的整数阶模型;与整数阶系统辨识算法相比,所提出的的系统辨识算法更稳定. 相似文献
16.
The shared parameter growth mixture model (SPGMM) has been proposed as a method to handle missing not at random (MNAR) data in longitudinal studies. This Monte Carlo simulation study compared the one-step approach with a three-step approach for adding covariates into the SPGMM. The results showed that performances of one-step and three-step approaches did not differ, but the estimate of the coefficient of the covariate was biased in most conditions with MNAR data. However, means, variances, and covariance of the intercept and slope as well as their standard errors were estimated without bias in most conditions, except for some combinations of small class distances and MNAR dropout missingness that was not related to the underlying growth trajectory. Classification accuracy was similar with both one-step and three-step SPGMM. 相似文献
17.
Fatigue damage assessment is carried out considering mean value effect by applying four criteria of failure. Three frequency domain methods, i.e., level crossing counting(LCC), range counting(RC) and a new proposed method, are applied. The core of frequency domain method is the construction of probability density function for the mean stress and stress range of the stress process. The applicability of these frequency domain methods are inspected by comparing with time domain method. Numerical simulations verify the applicability of LCC and the proposed method, while RC gives poor estimations. 相似文献
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INTRODUCTIONRoadvehiclesuspensiondesignhasreceivedgreatattentioninrecentyears .Theperformanceofthesuspensionsystemplaysanimportantroleinachievinggoodhandlingandridingcomfort.Practically ,thesimplestandmostcommontypesofsuspensionsarepassiveinthesensethatno… 相似文献
19.
A new kind of fuzzy control scheme, based on the identification of the signal's main frequency and the behavior of the ER
damper, is proposed to control the semi-active suspension system. This method adjusts the fuzzy controller to achieve the
best isolation effect by analyzing the main frequency's characters and inspecting the change of system parameters. The input
of the fuzzy controller is the main frequency and the optimal damping ratio is the output. Simulation results indicated that
the proposed control method is very effective in isolating the vibration.
Project (No. 69974024) supported by the National Natural Science Foundation of China 相似文献
20.
基于地震损伤性能的抗震设计方法 总被引：8，自引：0，他引：8
本文根据建筑结构基于性能的抗震设计思想,介绍了钢筋砼剪切型结构地震损伤模型及其性能参数的确定方法,根据国内外最新研究成果,通过与我国现行抗震设计规范三水准设计目标的比较,提出了地震损伤目标的确定和基于地震损伤性能的设计准则和方法． 相似文献