Natural frequencies of the bridge—vehicle coupling system considering uniform distributed load varying with position is investigated in this work.An analytic model of a simply supported beam bridge with constant sect...Natural frequencies of the bridge—vehicle coupling system considering uniform distributed load varying with position is investigated in this work.An analytic model of a simply supported beam bridge with constant section is introduced to establish the frequency equations of the coupled system.Comparisons with the results between analytic model and FEM indicate that the present research is correct and reasonable.In view of an example bridge,natural frequencies are studied on the bridge subjected to uniform distributed moving loads in cases of different weight and span,by which some regular phenomenon are obtained.The present study can apply in the engineering problem of interaction between bridges and moving loads such as trains and tracked vehicles.展开更多
To locate and quantify local damage in a simply supported bridge, in this study, we derived a rotational-angle influence line equation of a simply supported beam model with local damage. Using the diagram multiplicati...To locate and quantify local damage in a simply supported bridge, in this study, we derived a rotational-angle influence line equation of a simply supported beam model with local damage. Using the diagram multiplication method, we introduce an analytical formula for a novel damage-identification indicator, namely the diff erence of rotational-angle influence linescurvature(DRAIL-C). If the initial stiff ness of the simply supported beam is known, the analytical formula can be effectively used to determine the extent of damage under certain circumstances. We determined the effectiveness and anti-noise performance of this new damage-identification method using numerical examples of a simply supported beam, a simply supported hollow-slab bridge, and a simply supported truss bridge. The results show that the DRAIL-C is directly proportional to the moving concentrated load and inversely proportional to the distance between the bridge support and the concentrated load and the distance between the damaged truss girder and the angle measuring points. The DRAIL-C indicator is more sensitive to the damage in a steel-truss-bridge bottom chord than it is to the other elements.展开更多
针对未知家电负荷背景下基于智能电表采样数据进行异常负荷识别问题,以电动车入户充电负荷为出发点,提出了一种基于边缘计算的用户异常负荷识别方法。首先通过Boruta-SHAP算法对非侵入式负荷数据的14种特征进行排序筛选,得到在秒级负荷...针对未知家电负荷背景下基于智能电表采样数据进行异常负荷识别问题,以电动车入户充电负荷为出发点,提出了一种基于边缘计算的用户异常负荷识别方法。首先通过Boruta-SHAP算法对非侵入式负荷数据的14种特征进行排序筛选,得到在秒级负荷数据下的辨识效果最佳的特征子集;然后采用改进的非平行支持向量机(v-non parallel support vector machine,v-NPSVM)模型进行异常负荷识别模型的训练;最后结合边缘计算技术将算法部署到边缘计算平台上,实现对典型电动车充电负荷的识别。实验基于低压台区中智能电表获取的真实负荷数据进行验证,并进一步对数据进行降频处理以验证更低频数据源下方法的有效性,实验结果表明针对降频后的异常负荷识别的正确辨识率仍在90%以上,证明了在未知家电负荷背景下方法具有较好的适用性和准确性。展开更多
This paper aims to accurately identify parameters of the natural charging behavior characteristic(NCBC)for plug-in electric vehicles(PEVs) without measuring any data regarding charging request information of PEVs. To ...This paper aims to accurately identify parameters of the natural charging behavior characteristic(NCBC)for plug-in electric vehicles(PEVs) without measuring any data regarding charging request information of PEVs. To this end, a data-mining method is first proposed to extract the data of natural aggregated charging load(ACL) from the big data of aggregated residential load. Then, a theoretical model of ACL is derived based on the linear convolution theory. The NCBC-parameters are identified by using the mined ACL data and theoretical ACL model via the derived identification model. The proposed methodology is cost-effective and will not expose the privacy of PEVs as it does not need to install sub-metering systems to gather charging request information of each PEV. It is promising in designing unidirectional smart charging schemes which are attractive to power utilities. Case studies verify the feasibility and effectiveness of the proposed methodology.展开更多
针对基于车辆响应的间接测量法进行桥梁模态识别时,桥面不平度的影响难以滤除、高阶模态识别准确率较低等问题,提出一种基于盲源分离算法来分离车桥接触点响应信号中的桥面不平度效应与桥梁振动响应,进而实现桥梁模态识别的方法.首先,...针对基于车辆响应的间接测量法进行桥梁模态识别时,桥面不平度的影响难以滤除、高阶模态识别准确率较低等问题,提出一种基于盲源分离算法来分离车桥接触点响应信号中的桥面不平度效应与桥梁振动响应,进而实现桥梁模态识别的方法.首先,详细阐述了应用二阶盲识别(Second Order Blind Identification,SOBI)算法,以两组车桥接触点加速度响应信号作为输入信号,进而获取桥梁振动估计信号的原理和方法.然后,采用信号带通滤波和Hilbert变换并结合支点数据延拓的振型修正策略,建立了基于车辆响应的桥梁模态识别技术流程和框架.最后,依托数值算例对所提出方法的适用性和有效性进行了验证,并分析了车辆间距、桥面不平度和车辆频率等参数对方法适用性的影响.结果表明,所提出方法能有效滤除桥面不平度的影响,实现桥梁高阶模态的准确识别,且对多种关键因素的影响具有鲁棒性,具有精度高、操作简便和适用性强等特点,可为基于车辆响应的桥梁模态识别提供一种新思路.展开更多
文摘Natural frequencies of the bridge—vehicle coupling system considering uniform distributed load varying with position is investigated in this work.An analytic model of a simply supported beam bridge with constant section is introduced to establish the frequency equations of the coupled system.Comparisons with the results between analytic model and FEM indicate that the present research is correct and reasonable.In view of an example bridge,natural frequencies are studied on the bridge subjected to uniform distributed moving loads in cases of different weight and span,by which some regular phenomenon are obtained.The present study can apply in the engineering problem of interaction between bridges and moving loads such as trains and tracked vehicles.
基金supported by the National Natural Science Foundation of China(Nos.51608245 and 51568041)Natural Science Foundation of Gansu Province(Nos.148RJZA026 and 2014GS02269)
文摘To locate and quantify local damage in a simply supported bridge, in this study, we derived a rotational-angle influence line equation of a simply supported beam model with local damage. Using the diagram multiplication method, we introduce an analytical formula for a novel damage-identification indicator, namely the diff erence of rotational-angle influence linescurvature(DRAIL-C). If the initial stiff ness of the simply supported beam is known, the analytical formula can be effectively used to determine the extent of damage under certain circumstances. We determined the effectiveness and anti-noise performance of this new damage-identification method using numerical examples of a simply supported beam, a simply supported hollow-slab bridge, and a simply supported truss bridge. The results show that the DRAIL-C is directly proportional to the moving concentrated load and inversely proportional to the distance between the bridge support and the concentrated load and the distance between the damaged truss girder and the angle measuring points. The DRAIL-C indicator is more sensitive to the damage in a steel-truss-bridge bottom chord than it is to the other elements.
基金The National Natural Science Foundation of China Youth Program(No.52108139)Hunan Provincial Natural Science Foundation Youth Program(No.2023JJ40290).
文摘针对未知家电负荷背景下基于智能电表采样数据进行异常负荷识别问题,以电动车入户充电负荷为出发点,提出了一种基于边缘计算的用户异常负荷识别方法。首先通过Boruta-SHAP算法对非侵入式负荷数据的14种特征进行排序筛选,得到在秒级负荷数据下的辨识效果最佳的特征子集;然后采用改进的非平行支持向量机(v-non parallel support vector machine,v-NPSVM)模型进行异常负荷识别模型的训练;最后结合边缘计算技术将算法部署到边缘计算平台上,实现对典型电动车充电负荷的识别。实验基于低压台区中智能电表获取的真实负荷数据进行验证,并进一步对数据进行降频处理以验证更低频数据源下方法的有效性,实验结果表明针对降频后的异常负荷识别的正确辨识率仍在90%以上,证明了在未知家电负荷背景下方法具有较好的适用性和准确性。
基金supported by the NSFCRCUK_EPSRC(No.51361130153)the National Natural Science Foundation of China(No.51377035)
文摘This paper aims to accurately identify parameters of the natural charging behavior characteristic(NCBC)for plug-in electric vehicles(PEVs) without measuring any data regarding charging request information of PEVs. To this end, a data-mining method is first proposed to extract the data of natural aggregated charging load(ACL) from the big data of aggregated residential load. Then, a theoretical model of ACL is derived based on the linear convolution theory. The NCBC-parameters are identified by using the mined ACL data and theoretical ACL model via the derived identification model. The proposed methodology is cost-effective and will not expose the privacy of PEVs as it does not need to install sub-metering systems to gather charging request information of each PEV. It is promising in designing unidirectional smart charging schemes which are attractive to power utilities. Case studies verify the feasibility and effectiveness of the proposed methodology.
文摘针对基于车辆响应的间接测量法进行桥梁模态识别时,桥面不平度的影响难以滤除、高阶模态识别准确率较低等问题,提出一种基于盲源分离算法来分离车桥接触点响应信号中的桥面不平度效应与桥梁振动响应,进而实现桥梁模态识别的方法.首先,详细阐述了应用二阶盲识别(Second Order Blind Identification,SOBI)算法,以两组车桥接触点加速度响应信号作为输入信号,进而获取桥梁振动估计信号的原理和方法.然后,采用信号带通滤波和Hilbert变换并结合支点数据延拓的振型修正策略,建立了基于车辆响应的桥梁模态识别技术流程和框架.最后,依托数值算例对所提出方法的适用性和有效性进行了验证,并分析了车辆间距、桥面不平度和车辆频率等参数对方法适用性的影响.结果表明,所提出方法能有效滤除桥面不平度的影响,实现桥梁高阶模态的准确识别,且对多种关键因素的影响具有鲁棒性,具有精度高、操作简便和适用性强等特点,可为基于车辆响应的桥梁模态识别提供一种新思路.
