基于BIM正向设计的博物馆梁结构自动识别方法

为避免实际建筑物间梁柱结构的碰撞差异,导致的建筑受力不均,影响博物馆的安全稳定性,提出一种基于BIM正向设计的博物馆梁结构自动识别方法。BIM(Building Information Modeling)正向设计更强调专业间的互相协同,协同是以网络为基础的交流手段,给出基本硬件和服务器硬件配置;并以Revit软件为平台,通过计算单元截面与左右节点间距离的相位原理采集博物馆梁结构参数,获得梁柱的负荷特征;将其输入至负荷载入模块匹配,自动识别梁柱结构稳定性。仿真实验环境下,识别存在不同负荷程度的梁柱,识别结果与设定结果较为接近,方法有实际应用价值。

基于振动信号分析的结构损伤识别方法

根据近期文献,总结了结构损伤识别的一些方法,包括基于固有频率变化的损伤识别方法、基于振型变化的损伤识别方法、基于柔度变化的损伤识别方法、模型修正法、时频分析方法、基于环境激励的损伤识别方法、人工神经网络方法,指出了今后的发展趋势.

Damage Identification in Footbridges from Natural Frequency Measurements

The present study aims to develop a robust structural damage identification method that can be used for the evaluation of bridge structures. An approach for the structural damage identification based on the measurement of natural frequencies is presented. The structural damage model is assumed to be associated with a reduction of a contribution to the element stiffness matrix equivalent to a scalar reduction of the material modulus. A computational procedure for the direct iteration technique based on the non-linear perturbation theory is proposed to identify structural damage. The presented damage identification technique is applied to the footbridge over the Slunjcica River near Slunj to demonstrate the effectiveness of the proposed approach. Using a limited number of measured natural frequencies, reduction in the stiffness of up to 100% at multiple sites is detected. The results indicate that the proposed approach can be successful in not only predicting the location of damage but also in determining the extent of structural damage.

An Application of Damage Detection Methods to A Real World Structure Subjected to Ground Motion Excitation

This paper aims at investigating the efficacy of different state-of-art damage detection methods when applied to real worm structures subjected to ground motion excitations, for which the literature contributions are, at present, still not fully comprehensive. To this purpose the paper analyses two test structures： （1） a four-story scaled steel frame tested on a shake table in a controlled laboratory conditions, and （2） a seven-story reinforced concrete building monitored during the seismic excitations of the 1999 Chi-Chi （Taiwan） Earthquake main shock and numerous fore and afiershocks. Some model based damage approaches and statistics based damage indexes are reviewed. The different methodologies and indexes are, then, applied to the two test structures with the final aim of analysing their performance and validity within the case of a laboratory scaled model and a real world structure subjected to input ground motion.

Substructure isolation and damage identification using free responses

Structural health monitoring （SHM） has become a hot and intensively researched field in civil engineering. Thereinto, damage identification play an important role in maintaining structural integrity and safety. Many effective methods have been proposed for damage identification. However, accurate global identification of large real-world structures is not easy due to their com- plex and often unknown boundary conditions, nonlinear components, insensitivity of glohal response to localized damages, etc. Furthermore, global identification often requires lots of sensors and involves large number of unknowns. This is costly, rarely feasible in practice, and usually yields severely ill-conditioned identification problems. Substructuring approach is a possible solution： substructuring methods can focus on local small substructures; they need only a few sensors placed on the substruc- ture and yield smaller and numerically much more feasible identification problems. This paper proposed an improved sub- structure method using local free response for substructure damage identification. The virtual supports are constructed by Sub- structure Isolation Method （SIM） using the linear combination of the substructural responses. The influence of the global errors is isolated by adding the virtual supports on the main degree of freedoms （DOFs） of the substructure. Through the correlation analysis, the substructural modes are selected and used for damage identification of the substructure. A plain model of cable stayed bridge is used for the verification of the proposed method.