Showing papers by "Yong Xia published in 2014"
TL;DR: In this paper, a new hybrid reliability analysis technique based on the convex modeling theory is developed for structures with multi-source uncertainties, which may contain randomness, fuzziness, and non-probabilistic boundedness.
Abstract: A new hybrid reliability analysis technique based on the convex modeling theory is developed for structures with multi-source uncertainties, which may contain randomness, fuzziness, and non-probabilistic boundedness. By solving the convex modeling reliability problem and further analyzing the correlation within uncertainties, the structural hybrid reliability is obtained. Considering various cases of uncertainties of the structure, four hybrid models including the convex with random, convex with fuzzy random, convex with interval, and convex with other three are built, respectively. The present hybrid models are compared with the conventional probabilistic and the non-probabilistic models by two typical numerical examples. The results demonstrate the accuracy and effectiveness of the proposed hybrid reliability analysis method.
77 citations
TL;DR: In this article, a real-time monitoring strain data was used to calculate the displacement and tilt angle of a super-tall building in normal and typhoon conditions using virtual work theory.
70 citations
TL;DR: In this article, the authors transform the conventional implicit Newmark-β algorithm into an explicit form for the solution of the Ax=b equations, which is an equivalent transformation, and it exhibits the same characteristics of Newmarkβ algorithm as an implicit method.
65 citations
TL;DR: In this paper, a damage detection approach based on transmissibility in frequency domain is proposed to identify the damage of shear connectors in slab-on-girder bridge structures with or without reference data from the undamaged structure.
Abstract: Shear connectors are generally used to link the slab and girder together in slab-on-girder bridge structures. Damage of shear connectors in such structures will result in shear slippage between the slab and girder, which significantly reduces the load-carrying capacity of bridges. A damage detection approach based on transmissibility in frequency domain is proposed in this paper to identify the damage of shear connectors in slab-on-girder bridge structures with or without reference data from the undamaged structure. The transmissibility, which is an inherent system characteristic, indicates the relationship between two sets of response vectors in frequency domain. Measured input force and acceleration responses from hammer tests are analyzed to obtain the frequency response functions at the slab and girder sensor locations by the experimental modal analysis. The transmissibility matrix that relates the slab response to the girder response is then derived. By comparing the transmissibility vectors in undamaged and damaged states, the damage level of shear connectors can be identified. When the measurement data from the undamaged structure are not available, a study with only the measured response data in the damaged state for the condition assessment of shear connectors is also conducted. Numerical and experimental studies on damage detection of shear connectors linking a concrete slab to two steel girders are conducted to validate the accuracy and efficiency of the proposed approach. The results demonstrate that the proposed method can be used to identify shear connector damages accurately and efficiently. The proposed method is also applied to the condition evaluation of shear connectors in a real composite bridge with in-field testing data.
41 citations
TL;DR: The enhanced sensitivity-based method is shown to be capable of yielding more accurate identified results with noisy measurement in a planar truss structure compared to conventional sensitivity- based method.
38 citations
TL;DR: In this paper, an auto/cross-correlation function-based method using acceleration responses under multiple ambient white noise or impact excitations is presented. But the method is not suitable for the detection of structural components.
Abstract: Traditional structural system identification and damage detection methods use vibration responses under single excitation. This paper presents an auto/cross-correlation function-based method using acceleration responses under multiple ambient white noise or impact excitations. The auto/cross-correlation functions are divided into two parts. One is associated with the structural parameters and the other with the energy of the excitation. These two parts are updated sequentially using a two-stage method. Numerical and experimental studies are conducted to demonstrate the accuracy and robustness of the proposed method. The effects of measurement noise and number of measurement points on the identification results are also studied.
29 citations
TL;DR: In this article, a non-probabilistic interval analysis framework is developed to quantify the interval of the structural element stiffness parameters, according to which the possibility of damage existence is defined based on the reliability theory.
26 citations
TL;DR: In this paper, the eigenvalue and eigenvector derivatives of a structure based on a dynamic condensation technique are computed by iteratively updating the derivatives of the condensed system matrices and a transformation matrix.
16 citations
TL;DR: In this paper, a Kalman filter based floor settlement monitoring approach with the aid of forward construction stage analysis is presented, where the settlement of floors in the next stage is predicted with the forward construction stages analysis, so that the floor to be constructed can be pre-determined.
Abstract: Excessive and unexpected settlement of supertall buildings during the construction stage may affect structural safety. Floor settlement monitoring is imperative during the structural construction. The current practice is to measure floor settlement within a specific time frame and then compensate for the elevation error in the next construction stage. This posterior manner is inaccurate because it does not take account of measurement error and the real settlement in the next construction stage. This paper presents a Kalman filter based settlement monitoring approach with the aid of forward construction stage analysis. The settlement of floors in the next stage is predicted with the forward construction stage analysis. Consequently the elevation of the floor to be constructed can be pre-determined. The proposed method is demonstrated through construction settlement monitoring of the 632-m tall Shanghai Tower. The structure will be the tallest supertall building of China upon completed in 2014. It shows tha...
11 citations
01 Jan 2014
TL;DR: Cyxia et al. as mentioned in this paper proposed a method to solve the problem of the lack of resources in the Hong Kong Polytechnic University's Department of Civil and Environmental Engineering (HPE).
Abstract: 1 Associate professor, Department of Civil Engineering, Xiamen University, China 2 Research student, Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong 3 Associate professor, Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong 4 Professor, College of Civil Engineering, Fuzhou University, China *(Corresponding author: E-mail: ceyxia@polyu.edu.hk)
2 citations