针对传统方法子指标的不确定性问题,提出了一种基于三角直觉模糊网络分析法(triangular intuitionistic fuzzy analytic network process,TIFANP)、优劣解距离法(technique for order preference by similarity to an ideal solution,TO...针对传统方法子指标的不确定性问题,提出了一种基于三角直觉模糊网络分析法(triangular intuitionistic fuzzy analytic network process,TIFANP)、优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)和三角直觉模糊综合评价(triangular intuitionistic fuzzy comprehensive evaluation,TIFCE)的大跨桥梁安全状态评估方法。首先,建立大跨桥梁安全状态分层指标体系,采用TIFANP法确定考虑指标相互影响后的权重;其次,引入TOPSIS法分配指标各截面权重,进而获得子指标取值;然后,将桥梁安全状态划分为5级,通过TIFCE法构建指标在不同等级的隶属度和非隶属度函数,据此建立对应判断矩阵,并进行桥梁安全状态指数综合计算;最后,以某大跨悬索桥监测数据为依托,验证了所提方法的有效性。结果表明:所提方法能够更合理地处理评价指标间的相互影响以及专家评分时的不确定,可为运营期大跨桥梁安全状态的准确评估提供新思路。展开更多
针对单一监测信号难以实现电主轴复杂工况的精确评估问题,提出了一种基于熵权法改进D-S证据理论的分析方法。基于电主轴不同类型的监测信号,结合多域特征提取、主成分分析(Principal Component Analysis,PCA)算法和改进基于密度的噪声...针对单一监测信号难以实现电主轴复杂工况的精确评估问题,提出了一种基于熵权法改进D-S证据理论的分析方法。基于电主轴不同类型的监测信号,结合多域特征提取、主成分分析(Principal Component Analysis,PCA)算法和改进基于密度的噪声应用空间聚类(Density-Based Spatial Clustering of Applications with Noise,DBSCAN)算法,获取能够表征电主轴运行状态的特征指标。引入信度熵概念,基于熵权法对经典D-S证据理论算法进行改进,降低不敏感信号的干扰,改善了电主轴弱状态信息特征的融合效果。设计并搭建了电主轴试验台,对比研究了电主轴在不同转速下服役状态评估效果。依托现有的集成开发环境(Integrated Development Environment,IDE)开发了主轴运维信息管理评估系统,实现了电主轴服役过程中的数据采集、健康监测、状态评估的应用,满足了高精密电主轴运行维护的工程需求。为机床或电主轴等生产企业和设备制造企业提供系统的状态诊断与运维管理的系统解决方案。展开更多
为对某连续刚构桥进行状态评估,结合时变可靠度研究方法,考虑混凝土强度时变效应和预应力筋强度时变效应等因素,建立其时变可靠度模型,通过有限元软件进行模拟分析,采用不确定分析手段,对桥梁的相关统计参数进行抽样,对其连续刚构段进...为对某连续刚构桥进行状态评估,结合时变可靠度研究方法,考虑混凝土强度时变效应和预应力筋强度时变效应等因素,建立其时变可靠度模型,通过有限元软件进行模拟分析,采用不确定分析手段,对桥梁的相关统计参数进行抽样,对其连续刚构段进行计算,计算考虑时变因素下的桥梁失效概率并研究时变效应对评估桥梁失效概率的影响,得到设计使用年限内服役时间与可靠度指标之间的关系,对桥梁状态进行评估。研究表明,基于可靠度方法对现役桥梁状态进行评估时,考虑混凝土强度时变效应和预应力筋强度的时变效应计算得到的失效概率曲线斜率均大于不考虑时变效应时的曲线斜率,对桥梁状态预测的结果更为安全。For the state assessment of a certain continuous rigid-frame bridge, combined with the time-varying reliability research method, factors such as the time-varying effect of concrete strength and the time-varying effect of prestressed tendon strength are considered to establish its time-varying reliability model. Simulation analysis is conducted through finite-element software. Uncertainty analysis methods are used to sample the relevant statistical parameters of the bridge, and calculations are made for its continuous rigid-frame section to calculate the bridge failure probability considering time-varying factors and to study the impact of time-varying effects on the bridge failure probability. The relationship between the service time within the design service life and the reliability index is obtained to evaluate the bridge state. Research shows that when evaluating the state of existing bridges based on the reliability method, the slopes of the failure probability curves calculated by considering the time-varying effects of concrete strength and prestressed tendon strength are both greater than those of the curves without considering the time-varying effects, and the results of bridge state prediction are more reliable.展开更多
文摘针对传统方法子指标的不确定性问题,提出了一种基于三角直觉模糊网络分析法(triangular intuitionistic fuzzy analytic network process,TIFANP)、优劣解距离法(technique for order preference by similarity to an ideal solution,TOPSIS)和三角直觉模糊综合评价(triangular intuitionistic fuzzy comprehensive evaluation,TIFCE)的大跨桥梁安全状态评估方法。首先,建立大跨桥梁安全状态分层指标体系,采用TIFANP法确定考虑指标相互影响后的权重;其次,引入TOPSIS法分配指标各截面权重,进而获得子指标取值;然后,将桥梁安全状态划分为5级,通过TIFCE法构建指标在不同等级的隶属度和非隶属度函数,据此建立对应判断矩阵,并进行桥梁安全状态指数综合计算;最后,以某大跨悬索桥监测数据为依托,验证了所提方法的有效性。结果表明:所提方法能够更合理地处理评价指标间的相互影响以及专家评分时的不确定,可为运营期大跨桥梁安全状态的准确评估提供新思路。
文摘针对单一监测信号难以实现电主轴复杂工况的精确评估问题,提出了一种基于熵权法改进D-S证据理论的分析方法。基于电主轴不同类型的监测信号,结合多域特征提取、主成分分析(Principal Component Analysis,PCA)算法和改进基于密度的噪声应用空间聚类(Density-Based Spatial Clustering of Applications with Noise,DBSCAN)算法,获取能够表征电主轴运行状态的特征指标。引入信度熵概念,基于熵权法对经典D-S证据理论算法进行改进,降低不敏感信号的干扰,改善了电主轴弱状态信息特征的融合效果。设计并搭建了电主轴试验台,对比研究了电主轴在不同转速下服役状态评估效果。依托现有的集成开发环境(Integrated Development Environment,IDE)开发了主轴运维信息管理评估系统,实现了电主轴服役过程中的数据采集、健康监测、状态评估的应用,满足了高精密电主轴运行维护的工程需求。为机床或电主轴等生产企业和设备制造企业提供系统的状态诊断与运维管理的系统解决方案。
文摘为对某连续刚构桥进行状态评估,结合时变可靠度研究方法,考虑混凝土强度时变效应和预应力筋强度时变效应等因素,建立其时变可靠度模型,通过有限元软件进行模拟分析,采用不确定分析手段,对桥梁的相关统计参数进行抽样,对其连续刚构段进行计算,计算考虑时变因素下的桥梁失效概率并研究时变效应对评估桥梁失效概率的影响,得到设计使用年限内服役时间与可靠度指标之间的关系,对桥梁状态进行评估。研究表明,基于可靠度方法对现役桥梁状态进行评估时,考虑混凝土强度时变效应和预应力筋强度的时变效应计算得到的失效概率曲线斜率均大于不考虑时变效应时的曲线斜率,对桥梁状态预测的结果更为安全。For the state assessment of a certain continuous rigid-frame bridge, combined with the time-varying reliability research method, factors such as the time-varying effect of concrete strength and the time-varying effect of prestressed tendon strength are considered to establish its time-varying reliability model. Simulation analysis is conducted through finite-element software. Uncertainty analysis methods are used to sample the relevant statistical parameters of the bridge, and calculations are made for its continuous rigid-frame section to calculate the bridge failure probability considering time-varying factors and to study the impact of time-varying effects on the bridge failure probability. The relationship between the service time within the design service life and the reliability index is obtained to evaluate the bridge state. Research shows that when evaluating the state of existing bridges based on the reliability method, the slopes of the failure probability curves calculated by considering the time-varying effects of concrete strength and prestressed tendon strength are both greater than those of the curves without considering the time-varying effects, and the results of bridge state prediction are more reliable.
