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Yuanhai Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Shear lag analysis of thin-walled box girders based on a new Generalized Displacement
    Engineering Structures, 2014
    Co-Authors: Yuanhai Zhang, Li-xia Lin
    Abstract:

    Abstract In many papers about the shear lag analysis of thin-walled box girders, the maximum angular rotation attributable to the in-plane shear deformation of flanges is adopted as Generalized Displacement. However, the Generalized Displacement is not very simple and clear and the analytical procedure is relatively complicated. Moreover, various types of warping Displacement function for shear lag were assumed which may cause some confusion. In this paper, a new method for analyzing shear lag effect in thin-walled box girders is proposed in which the additional deflection induced by shear lag effect is adopted as the Generalized Displacement. Based on the Generalized moment defined in this paper, the shear lag deformation state is separated from the flexural deformation state of the corresponding elementary beam and analyzed as a fundamental deformation state. The quadratic parabola is demonstrated to be the reasonable curve of the warping Displacement function in the shear lag effect analysis of a box girder and the accuracy of the degrees of the warping functions is evaluated. The so-called negative shear lag is illustrated through the Generalized moment. The governing differential equation and the boundary condition for the additional deflection are established by applying the principle of minimum potential energy, and the initial parameter solution to the differential equation is provided. A very simple and convenient formula of the shear lag warping stress is proposed which has the same form as that of the bending stress of elementary beam. A finite beam segment element with 8 degrees of freedom is developed to analyze the shear lag effect in complex continuous box girders with varying depth. Two plexiglass models of continuous box girders are analyzed and the calculated results are in agreement with the test results, which validates the analytical method and the element presented.

  • Shear Lag Analysis of Thin-Walled Box Girders Adopting Additional Deflection as Generalized Displacement
    Journal of Engineering Mechanics, 2014
    Co-Authors: Yuanhai Zhang, Li-xia Lin
    Abstract:

    AbstractThe shear lag effect is one of the very important mechanical characteristics of thin-walled box girders and has been studied over several decades. However, the Generalized Displacement adopted in many papers is not very simple or clear, and the analytical procedure is somewhat complicated. In this paper, a new method for analyzing the shear lag effect in thin-walled box girders is proposed in which the additional deflection induced by the shear lag effect is adopted as a Generalized Displacement to describe the shear lag deformation state. Based on the Generalized moment for shear lag defined in this paper, the shear lag deformation state is separated from the flexural deformation state of the corresponding elementary beam and analyzed as a fundamental deformation state. The governing differential equation and boundary condition for the additional deflection are established by applying the principle of minimum potential energy, and the initial parameter solution to the differential equation is giv...

  • improved finite segment method for analyzing shear lag effect in thin walled box girders
    Journal of Structural Engineering-asce, 2012
    Co-Authors: Yuanhai Zhang
    Abstract:

    AbstractShear lag effect in thin-walled box girders has been studied over several decades. However, the methods adopted in many papers have some deficiencies. In the present work, an improved Displacement function for shear lag warping in a box girder with cantilever slabs is established. Based on the concept of Generalized force corresponding to the Generalized Displacement for shear lag and the relevant geometrical properties, an improved finite-segment method is proposed to simplify the shear lag analysis of complex box girders. The homogeneous solution of the governing differential equation for shear lag is adopted as the element Displacement function. The formulas of the element stiffness matrix and the equivalent nodal force vector are derived. A general formula expressed in terms of the Generalized moment is presented to calculate the stress. A finite-element computer program is developed by using FORTRAN language and is used to analyze a cantilever box girder model and a continuous prestressed con...

Han Jiayi - One of the best experts on this subject based on the ideXlab platform.

  • progressive recognition method for damaged cable load and linear Displacement through mixed monitoring
    2014
    Co-Authors: Han Yulin, Ye Lei, Han Jiayi
    Abstract:

    The invention relates to a progressive recognition method for damaged cable load and linear Displacement through mixed monitoring. According to the method, based on mixed monitoring, whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring cable structure temperature and environment temperature, a new mechanical calculation reference model, with the cable structure temperature and the environment temperature included, of the cable structure is obtained, and a unit damage monitored parameter numerical value varying matrix is obtained through calculation based on the model. According to the approximate linear relation existing among current numerical value vectors of monitored parameters, current initial numerical value vectors of the monitored parameters, the unit damage monitored parameter numerical value varying matrix and the current nominal damage vector of an evaluation object to be solved, a noninferior solution of the current nominal damage vector of the evaluation object is calculated, and accordingly Generalized Displacement of a supporting base, a damaged cable and the load variable quantity can be recognized when the temperature changes.

  • damaged cable load Generalized Displacement recognition method through mixed monitoring
    2014
    Co-Authors: Han Yulin, Han Jiayi
    Abstract:

    The invention relates to a damaged cable load Generalized Displacement recognition method through mixed monitoring. According to the method, based on mixed monitoring, whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring cable structure temperature and environment temperature, a new mechanical calculation reference model, with the cable structure temperature and the environment temperature included, of the cable structure is obtained, and a unit damage monitored parameter numerical value varying matrix is obtained through calculation based on the model. According to the approximate linear relation existing among current numerical value vectors of monitored parameters, current initial numerical value vectors of the monitored parameters, the unit damage monitored parameter numerical value varying matrix and the current nominal damage vector of an evaluation object to be solved, a noninferior solution of the current nominal damage vector of the evaluation object is calculated, and accordingly Generalized Displacement of a supporting base, a damaged cable and the load variable quantity can be recognized when the temperature changes.

  • progressive recognition method for problem cable load Generalized Displacement based on mixing monitoring
    2014
    Co-Authors: Han Yulin, Han Jiayi
    Abstract:

    The invention discloses a recognition method for problem cable load Generalized Displacement based on mixing monitoring. According to the progressive recognition method, whether the mechanical calculation reference model of a cable structure needs to be updated or not is determined through monitoring cable structure temperature and environment temperature, so that a mechanical calculation reference model, taking the structure temperature and the environment temperature into account, of the cable structure is obtained, and based on the model, a unit damage monitored parameter value change matrix is obtained through calculation. Based on approximate linear relations existing among current value vectors of monitored parameters, current initial value vectors of the monitored parameters, the unit damage monitored parameter value change matrix and current nominal damage vectors of evaluated objects to be solved, non-inferior solutions of the current nominal damage vectors of the evaluated objects are calculated, and therefore when the temperature changes, the support Generalized Displacement, a load change quantity and a problem cable can be recognized.

  • damaged cable load Generalized Displacement recognition method based on space coordinate monitoring
    2014
    Co-Authors: Han Yulin, Han Jiayi
    Abstract:

    The invention provides a damaged cable load Generalized Displacement recognition method based on space coordinate monitoring. The method includes the steps of determining whether a mechanical calculation reference model of a cable structure needs to be updated by monitoring the cable structural temperature and the environment temperature on the basis of space coordinate monitoring, obtaining a new mechanical calculation reference model, including the cable structure temperature and the environment temperature, of the cable structure, and carrying out calculation on the basis of the new mechanical calculation reference model to obtain a value change matrix of monitored data in unit damage. According to the approximate linear relation between the current value vector of monitored data and the current initial value vector of the monitored data and the approximate linear relation between the value change matrix of the monitored data in unit damage and the current nominal damage vector to be solved of evaluated objects, the non-inferior solution of the current nominal damage vector of the evaluated objects can be calculated. In this way, the Generalized Displacement and the load variation quantity of a support and damaged cables can be recognized when the temperature changes.

  • strain monitoring damaged cable centralized load Generalized Displacement progressive recognition method
    2014
    Co-Authors: Han Yulin, Ye Lei, Han Jiayi
    Abstract:

    Disclosed is a strain-monitoring damaged cable centralized load Generalized Displacement progressive recognition method. The strain-monitoring damaged cable centralized load Generalized Displacement progressive recognition method is based on strain monitoring. Whether a mechanical calculation reference model of a cable structure needs updating or not is determined through monitored cable structure temperature and environment temperature, and the mechanical calculation reference model, where the cable structure temperature and the environment temperature are reckoned, of the cable structure is acquired. A unit damage monitored amount numerical value variation matrix is acquired on the basis of the model. The non-inferior solution of an evaluated object current name damage vector is worked out according to the approximate linear relation between a monitored amount current numeric vector and a monitored amount current initial numerical value vector, the unit damage monitored amount value variation matrix and the evaluated object current name damage vector to be worked out. Accordingly, when temperature changes, a support Generalized Displacement, centralized load variable quantity and a damaged cable can be recognized at the same time.

Han Yulin - One of the best experts on this subject based on the ideXlab platform.

  • progressive recognition method for damaged cable load and linear Displacement through mixed monitoring
    2014
    Co-Authors: Han Yulin, Ye Lei, Han Jiayi
    Abstract:

    The invention relates to a progressive recognition method for damaged cable load and linear Displacement through mixed monitoring. According to the method, based on mixed monitoring, whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring cable structure temperature and environment temperature, a new mechanical calculation reference model, with the cable structure temperature and the environment temperature included, of the cable structure is obtained, and a unit damage monitored parameter numerical value varying matrix is obtained through calculation based on the model. According to the approximate linear relation existing among current numerical value vectors of monitored parameters, current initial numerical value vectors of the monitored parameters, the unit damage monitored parameter numerical value varying matrix and the current nominal damage vector of an evaluation object to be solved, a noninferior solution of the current nominal damage vector of the evaluation object is calculated, and accordingly Generalized Displacement of a supporting base, a damaged cable and the load variable quantity can be recognized when the temperature changes.

  • damaged cable load Generalized Displacement recognition method through mixed monitoring
    2014
    Co-Authors: Han Yulin, Han Jiayi
    Abstract:

    The invention relates to a damaged cable load Generalized Displacement recognition method through mixed monitoring. According to the method, based on mixed monitoring, whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring cable structure temperature and environment temperature, a new mechanical calculation reference model, with the cable structure temperature and the environment temperature included, of the cable structure is obtained, and a unit damage monitored parameter numerical value varying matrix is obtained through calculation based on the model. According to the approximate linear relation existing among current numerical value vectors of monitored parameters, current initial numerical value vectors of the monitored parameters, the unit damage monitored parameter numerical value varying matrix and the current nominal damage vector of an evaluation object to be solved, a noninferior solution of the current nominal damage vector of the evaluation object is calculated, and accordingly Generalized Displacement of a supporting base, a damaged cable and the load variable quantity can be recognized when the temperature changes.

  • progressive recognition method for problem cable load Generalized Displacement based on mixing monitoring
    2014
    Co-Authors: Han Yulin, Han Jiayi
    Abstract:

    The invention discloses a recognition method for problem cable load Generalized Displacement based on mixing monitoring. According to the progressive recognition method, whether the mechanical calculation reference model of a cable structure needs to be updated or not is determined through monitoring cable structure temperature and environment temperature, so that a mechanical calculation reference model, taking the structure temperature and the environment temperature into account, of the cable structure is obtained, and based on the model, a unit damage monitored parameter value change matrix is obtained through calculation. Based on approximate linear relations existing among current value vectors of monitored parameters, current initial value vectors of the monitored parameters, the unit damage monitored parameter value change matrix and current nominal damage vectors of evaluated objects to be solved, non-inferior solutions of the current nominal damage vectors of the evaluated objects are calculated, and therefore when the temperature changes, the support Generalized Displacement, a load change quantity and a problem cable can be recognized.

  • damaged cable load Generalized Displacement recognition method based on space coordinate monitoring
    2014
    Co-Authors: Han Yulin, Han Jiayi
    Abstract:

    The invention provides a damaged cable load Generalized Displacement recognition method based on space coordinate monitoring. The method includes the steps of determining whether a mechanical calculation reference model of a cable structure needs to be updated by monitoring the cable structural temperature and the environment temperature on the basis of space coordinate monitoring, obtaining a new mechanical calculation reference model, including the cable structure temperature and the environment temperature, of the cable structure, and carrying out calculation on the basis of the new mechanical calculation reference model to obtain a value change matrix of monitored data in unit damage. According to the approximate linear relation between the current value vector of monitored data and the current initial value vector of the monitored data and the approximate linear relation between the value change matrix of the monitored data in unit damage and the current nominal damage vector to be solved of evaluated objects, the non-inferior solution of the current nominal damage vector of the evaluated objects can be calculated. In this way, the Generalized Displacement and the load variation quantity of a support and damaged cables can be recognized when the temperature changes.

  • strain monitoring damaged cable centralized load Generalized Displacement progressive recognition method
    2014
    Co-Authors: Han Yulin, Ye Lei, Han Jiayi
    Abstract:

    Disclosed is a strain-monitoring damaged cable centralized load Generalized Displacement progressive recognition method. The strain-monitoring damaged cable centralized load Generalized Displacement progressive recognition method is based on strain monitoring. Whether a mechanical calculation reference model of a cable structure needs updating or not is determined through monitored cable structure temperature and environment temperature, and the mechanical calculation reference model, where the cable structure temperature and the environment temperature are reckoned, of the cable structure is acquired. A unit damage monitored amount numerical value variation matrix is acquired on the basis of the model. The non-inferior solution of an evaluated object current name damage vector is worked out according to the approximate linear relation between a monitored amount current numeric vector and a monitored amount current initial numerical value vector, the unit damage monitored amount value variation matrix and the evaluated object current name damage vector to be worked out. Accordingly, when temperature changes, a support Generalized Displacement, centralized load variable quantity and a damaged cable can be recognized at the same time.

Li-xia Lin - One of the best experts on this subject based on the ideXlab platform.

  • Shear Lag Analysis of Thin-Walled Box Girders Adopting Additional Deflection as Generalized Displacement
    Journal of Engineering Mechanics, 2014
    Co-Authors: Yuanhai Zhang, Li-xia Lin
    Abstract:

    AbstractThe shear lag effect is one of the very important mechanical characteristics of thin-walled box girders and has been studied over several decades. However, the Generalized Displacement adopted in many papers is not very simple or clear, and the analytical procedure is somewhat complicated. In this paper, a new method for analyzing the shear lag effect in thin-walled box girders is proposed in which the additional deflection induced by the shear lag effect is adopted as a Generalized Displacement to describe the shear lag deformation state. Based on the Generalized moment for shear lag defined in this paper, the shear lag deformation state is separated from the flexural deformation state of the corresponding elementary beam and analyzed as a fundamental deformation state. The governing differential equation and boundary condition for the additional deflection are established by applying the principle of minimum potential energy, and the initial parameter solution to the differential equation is giv...

  • Shear lag analysis of thin-walled box girders based on a new Generalized Displacement
    Engineering Structures, 2014
    Co-Authors: Yuanhai Zhang, Li-xia Lin
    Abstract:

    Abstract In many papers about the shear lag analysis of thin-walled box girders, the maximum angular rotation attributable to the in-plane shear deformation of flanges is adopted as Generalized Displacement. However, the Generalized Displacement is not very simple and clear and the analytical procedure is relatively complicated. Moreover, various types of warping Displacement function for shear lag were assumed which may cause some confusion. In this paper, a new method for analyzing shear lag effect in thin-walled box girders is proposed in which the additional deflection induced by shear lag effect is adopted as the Generalized Displacement. Based on the Generalized moment defined in this paper, the shear lag deformation state is separated from the flexural deformation state of the corresponding elementary beam and analyzed as a fundamental deformation state. The quadratic parabola is demonstrated to be the reasonable curve of the warping Displacement function in the shear lag effect analysis of a box girder and the accuracy of the degrees of the warping functions is evaluated. The so-called negative shear lag is illustrated through the Generalized moment. The governing differential equation and the boundary condition for the additional deflection are established by applying the principle of minimum potential energy, and the initial parameter solution to the differential equation is provided. A very simple and convenient formula of the shear lag warping stress is proposed which has the same form as that of the bending stress of elementary beam. A finite beam segment element with 8 degrees of freedom is developed to analyze the shear lag effect in complex continuous box girders with varying depth. Two plexiglass models of continuous box girders are analyzed and the calculated results are in agreement with the test results, which validates the analytical method and the element presented.

Zhibo Yang - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of shallow hyperbolic shell by different kinds of wavelet elements based on B-spline wavelet on the interval
    Applied Mathematical Modelling, 2016
    Co-Authors: Xingwu Zhang, Hao Zuo, Jixuan Liu, Xuefeng Chen, Zhibo Yang
    Abstract:

    Abstract Shallow hyperbolic shell is a typical structure widely used in mechanical engineering and architectural engineering. Accurate structural analysis is a very important procedure before it is used in practical engineering. Wavelet finite element method (WFEM) is a new numerical analysis method which takes wavelet functions to replace the polynomial functions in tradition FEM. Due to the excellent properties of wavelet, WFEM can improve the calculation efficiency and reduce the computational time. However, traditional WFEM mainly focuses on accurate analysis of Generalized Displacement, Generalized stress and Generalized strain should be calculated secondly through Displacement. Multivariable WFEM, including WFEM with two kinds of variables and WFEM with three kinds of variables, can independently interpolate the Generalized Displacement, stress and strain in one time, thus the calculation time is greatly reduced and the calculation precision can be improved significantly. In this paper, taking B-spline wavelet on the interval (BSWI) as interpolating function, the traditional BSWI element, BSWI element with two kinds of variables and BSWI element with three kinds of variables for the typical shell structure-shallow hyperbolic shell are constructed. Through bending and vibration analysis of shallow hyperbolic shell, the superiority of these three constructed elements is proved.