Nonlinear time-domain simulations are often used to predict the structural response at the design stage to ensure the acceptable operation and/or survival of floating structures under extreme conditions.An environment...Nonlinear time-domain simulations are often used to predict the structural response at the design stage to ensure the acceptable operation and/or survival of floating structures under extreme conditions.An environmental contour(EC)is commonly employed to identify critical sea states that serve as the input for numerical simulations to assess the safety and performance of marine structures.In many studies,marginal and conditional distributions are defined to construct bivariate joint probability distributions for variables,such as significant wave height and zero-crossing period.Then,ECs can be constructed using the inverse first-order reliability method(IFORM).This study adopts alternative models to describe the generalized dependence structure between environmental variables using copulas and discusses the Nataf transformation as a special case.ECs are constructed using measured wave data from moored buoys.Derived design loads are applied on a semisubmersible platform to assess possible differences.In addition,a linear interpolation scheme is utilized to establish a parametric model using short-term extreme tension distribution parameters and wave data,and the long-term tension response is estimated using Monte Carlo simulation.A 3D IFORM-based approach,in which the short-term extreme response that is ignored in the EC approach is used as the third variable,is proposed to help establish accurate design loads with increased accuracy.Results offer a clear illustration of the extreme responses of floating structures based on different models.展开更多
In order to couple the numerical simulation of a primary test stand driver with an optimal load design, a zero- dimensional wire array load model is designed based on the Saturn load model using PSPICE, which is an up...In order to couple the numerical simulation of a primary test stand driver with an optimal load design, a zero- dimensional wire array load model is designed based on the Saturn load model using PSPICE, which is an upgraded version of the Simulation Program with Integrated Circuit Emphasis （SPICE） designed by the ORCAD Corporation to perform circuit simulations. This paper calculates different load parameters and discusses factors influencing the driving current curve. With appropriate driving current curves chosen, further magneto-hydrodynamic calculations are carried out and discussed to provide the best results for experiments. The suggested optimal load parameters play an important role in experimental load design.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.52171284.
文摘Nonlinear time-domain simulations are often used to predict the structural response at the design stage to ensure the acceptable operation and/or survival of floating structures under extreme conditions.An environmental contour(EC)is commonly employed to identify critical sea states that serve as the input for numerical simulations to assess the safety and performance of marine structures.In many studies,marginal and conditional distributions are defined to construct bivariate joint probability distributions for variables,such as significant wave height and zero-crossing period.Then,ECs can be constructed using the inverse first-order reliability method(IFORM).This study adopts alternative models to describe the generalized dependence structure between environmental variables using copulas and discusses the Nataf transformation as a special case.ECs are constructed using measured wave data from moored buoys.Derived design loads are applied on a semisubmersible platform to assess possible differences.In addition,a linear interpolation scheme is utilized to establish a parametric model using short-term extreme tension distribution parameters and wave data,and the long-term tension response is estimated using Monte Carlo simulation.A 3D IFORM-based approach,in which the short-term extreme response that is ignored in the EC approach is used as the third variable,is proposed to help establish accurate design loads with increased accuracy.Results offer a clear illustration of the extreme responses of floating structures based on different models.
文摘In order to couple the numerical simulation of a primary test stand driver with an optimal load design, a zero- dimensional wire array load model is designed based on the Saturn load model using PSPICE, which is an upgraded version of the Simulation Program with Integrated Circuit Emphasis （SPICE） designed by the ORCAD Corporation to perform circuit simulations. This paper calculates different load parameters and discusses factors influencing the driving current curve. With appropriate driving current curves chosen, further magneto-hydrodynamic calculations are carried out and discussed to provide the best results for experiments. The suggested optimal load parameters play an important role in experimental load design.
