The Experts below are selected from a list of 98469 Experts worldwide ranked by ideXlab platform

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

  • application of Response Surface Method and multi objective genetic algorithm to configuration optimization of shell and tube heat exchanger with fold helical baffles
    Applied Thermal Engineering, 2018
    Co-Authors: Simin Wang, Juan Xiao, Jiarui Wang, Guanping Jian, Jian Wen, Zaoxiao Zhang
    Abstract:

    Abstract A kind of shell-and-tube heat exchangers with fold baffles was proposed to eliminate the triangular leakage zones between adjacent baffles. An effective algorithm combing second-order polynomial Response Surface Method and multi-objective genetic algorithm was adopted to study the effect of fold baffle configuration parameters on the performance of flow and heat transfer. The helical angle, overlapped degree and shell-side inlet velocity were chosen as design parameters, and the Nusselt number and shell-side pressure drop were considered as objective functions. The results show that both the Nusselt number and shell-side pressure drop increase with the decrease of helical angle and shell-side inlet velocity, and increase with the increasing overlapped degree. A set of Pareto-optimal points were obtained, and the optimization results illustrate a good agreement with CFD simulation data with the relative deviation less than ±3%. And the empirical correlations of Nusselt number and friction coefficient were obtained based on Response Surface Method, the helical angle and overlapped degree were fitted into empirical correlations as correction factors for the first time. It is found that the adjusted coefficient of determination of the Nusselt number and friction coefficient is 0.943 and 0.999, respectively, which illustrate the fitting is correct and reliable.

Zhiping Qiu - One of the best experts on this subject based on the ideXlab platform.

  • an efficient Response Surface Method considering the nonlinear trend of the actual limit state
    Structural Engineering and Mechanics, 2013
    Co-Authors: Weitao Zhao, Zhiping Qiu, Yi Yang
    Abstract:

    In structural reliability analysis, the Response Surface Method is a powerful Method to evaluate the probability of failure. However, the location of experimental points used to form a Response Surface function must be selected in a judicious way. It is necessary for the highly nonlinear limit state functions to consider the design point and the nonlinear trend of the limit state, because both of them influence the probability of failure. In this paper, in order to approximate the actual limit state more accurately, experimental points are selected close to the design point and the actual limit state, and consider the nonlinear trend of the limit state. Linear, quadratic and cubic polynomials without mixed terms are utilized to approximate the actual limit state. The direct Monte Carlo simulation on the approximated limit state is carried out to determine the probability of failure. Four examples are given to demonstrate the efficiency and the accuracy of the proposed Method for both numerical and implicit limit states.

  • an efficient Response Surface Method and its application to structural reliability and reliability basedoptimization
    Finite Elements in Analysis and Design, 2013
    Co-Authors: Weitao Zhao, Zhiping Qiu
    Abstract:

    In structural reliability analysis, the Response Surface Method is widely used to reduce the computational efforts of engineering analyses. However, in order to reduce the number of finite element analysis and ensure the accuracy of evaluation, the locations of experimental points used to form a Response Surface function must be selected in a judicious way. Therefore, in this study, the control point of experimental points is constructed. The new center point of experimental points is chosen by using the control point instead of the design point. The control point can guarantee that the center point of experimental points lies exactly on the failure Surface and is close to the actual design point. Two improved Methods are proposed based on the control point and the moving technique of experimental points considering the compromise between the accuracy and the efficiency. Five examples are given to demonstrate the efficiency and the accuracy of the proposed Method for both structural reliability and reliability-based structural optimization.

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

  • stochastic characteristic analysis of turbine rotor based on Response Surface Method
    International Conference on Industrial Mechatronics and Automation, 2010
    Co-Authors: Zonghe Zhou, Zichun Yang
    Abstract:

    In order to improve the reliability of turbine rotor design, Response Surface Method is introduced into probability finite element, and geometrical parameters, material parameters and load parameters of rotor are considered as input random variables, through calculating and then obtaining the statistical characteristics and cumulative distribution function of stochastic Response of the rotor. Then, probability sensitivities analysis is applied to evaluate how much the output parameters are influenced by the random input parameters. In the last, through analyzing Scatter plots of structural Responses with respect to the random input variables, advancing how to improve the reliability of rotor. The results show that using this Method leads to fast speed, much less amount of calculation and high accuracy.

Weitao Zhao - One of the best experts on this subject based on the ideXlab platform.

  • an improvement of the Response Surface Method based on reference points for structural reliability analysis
    Ksce Journal of Civil Engineering, 2016
    Co-Authors: Weitao Zhao, Weihua Liu, Qijiao Yang
    Abstract:

    The Response Surface Method (RSM) is a powerful technique to evaluate the structural reliability. However, for a Limit State Function (LSF) with highly non-linear, the accuracy of the approximation of the failure probability does not depend very much upon the design point. It is necessary for RSMs to consider the design point and the non-linear trend of actual LSF around the design point, because both of them influence the failure probability. Thus, in order to improve the fitting precision of the Response Surface Function (RSF) to the actual LSF over a larger region containing the design point, the reference points of experimental points are constructed in this paper. Experimental points used to obtain parameters of a RSF are selected according to the information of reference points. Four examples are discussed in detail. The numerical results indicate that the accuracy and the efficiency of the proposed Method are both desirable for both numerical and implicit LSFs, and the proposed Method is superior to the classical RSM in terms of efficiency and accuracy.

  • an efficient Response Surface Method considering the nonlinear trend of the actual limit state
    Structural Engineering and Mechanics, 2013
    Co-Authors: Weitao Zhao, Zhiping Qiu, Yi Yang
    Abstract:

    In structural reliability analysis, the Response Surface Method is a powerful Method to evaluate the probability of failure. However, the location of experimental points used to form a Response Surface function must be selected in a judicious way. It is necessary for the highly nonlinear limit state functions to consider the design point and the nonlinear trend of the limit state, because both of them influence the probability of failure. In this paper, in order to approximate the actual limit state more accurately, experimental points are selected close to the design point and the actual limit state, and consider the nonlinear trend of the limit state. Linear, quadratic and cubic polynomials without mixed terms are utilized to approximate the actual limit state. The direct Monte Carlo simulation on the approximated limit state is carried out to determine the probability of failure. Four examples are given to demonstrate the efficiency and the accuracy of the proposed Method for both numerical and implicit limit states.

  • an efficient Response Surface Method and its application to structural reliability and reliability basedoptimization
    Finite Elements in Analysis and Design, 2013
    Co-Authors: Weitao Zhao, Zhiping Qiu
    Abstract:

    In structural reliability analysis, the Response Surface Method is widely used to reduce the computational efforts of engineering analyses. However, in order to reduce the number of finite element analysis and ensure the accuracy of evaluation, the locations of experimental points used to form a Response Surface function must be selected in a judicious way. Therefore, in this study, the control point of experimental points is constructed. The new center point of experimental points is chosen by using the control point instead of the design point. The control point can guarantee that the center point of experimental points lies exactly on the failure Surface and is close to the actual design point. Two improved Methods are proposed based on the control point and the moving technique of experimental points considering the compromise between the accuracy and the efficiency. Five examples are given to demonstrate the efficiency and the accuracy of the proposed Method for both structural reliability and reliability-based structural optimization.

Simin Wang - One of the best experts on this subject based on the ideXlab platform.

  • application of Response Surface Method and multi objective genetic algorithm to configuration optimization of shell and tube heat exchanger with fold helical baffles
    Applied Thermal Engineering, 2018
    Co-Authors: Simin Wang, Juan Xiao, Jiarui Wang, Guanping Jian, Jian Wen, Zaoxiao Zhang
    Abstract:

    Abstract A kind of shell-and-tube heat exchangers with fold baffles was proposed to eliminate the triangular leakage zones between adjacent baffles. An effective algorithm combing second-order polynomial Response Surface Method and multi-objective genetic algorithm was adopted to study the effect of fold baffle configuration parameters on the performance of flow and heat transfer. The helical angle, overlapped degree and shell-side inlet velocity were chosen as design parameters, and the Nusselt number and shell-side pressure drop were considered as objective functions. The results show that both the Nusselt number and shell-side pressure drop increase with the decrease of helical angle and shell-side inlet velocity, and increase with the increasing overlapped degree. A set of Pareto-optimal points were obtained, and the optimization results illustrate a good agreement with CFD simulation data with the relative deviation less than ±3%. And the empirical correlations of Nusselt number and friction coefficient were obtained based on Response Surface Method, the helical angle and overlapped degree were fitted into empirical correlations as correction factors for the first time. It is found that the adjusted coefficient of determination of the Nusselt number and friction coefficient is 0.943 and 0.999, respectively, which illustrate the fitting is correct and reliable.