In the process of suction penetration of bucket foundations with inner compartments for offshore wind turbines,most researches focus on soil seepage failure and soil plugs,while the buckling of foundations is rarely i...In the process of suction penetration of bucket foundations with inner compartments for offshore wind turbines,most researches focus on soil seepage failure and soil plugs,while the buckling of foundations is rarely investigated.Therefore,theoretical calculation methods for critical buckling pressures of the skirt and bulkheads of the bucket foundation are first presented according to the stability theory of a cylindrical shell and the small deflection theory of a thin plate,respectively.Furthermore,two types of models with and without considering the skirt-soil interaction are developed for the calculation of critical buckling pressure of the bucket foundation.Taking a practical project as an example,theoretical and numerical methods are used to obtain the critical buckling pressures of a bucket foundation.In this work,the theoretical method and the finite element model considering the skirt-soil interaction for calculating the critical buckling pressure of bucket foundations are firstly proposed.The results can help to optimize the design process of offshore wind turbine foundations and improve the safety of offshore wind power systems.展开更多
Submarine pressure hulls,fire-tube boilers,vacuum tanks,oil well casings,submersibles,underground pipelines,tunnels,rocket motor casing,etc.,are some of the examples of thin cylindrical shell structures which collapse...Submarine pressure hulls,fire-tube boilers,vacuum tanks,oil well casings,submersibles,underground pipelines,tunnels,rocket motor casing,etc.,are some of the examples of thin cylindrical shell structures which collapse due to buckling under uniform pressure.To enhance the buckling strength of bare cylin-drical shells,one of the best solutions is to stiffen them with ring stiffeners.In this work in order to predict the shell instability failure mode(SIFM)and general instability failure mode(GIFM)FE models are generated and analysed using buckling analysis of general-purpose FE software ANSYS.The numeri-cal results obtained using FE analysis are compared with published analytical and experimental results.Hence in the present study effort s are taken to develop FE models to predict global and shell instability failure modes of externally ring stiffened cylindrical shells by using linear FE analysis.It is proposed to use full/half bare cylindrical shell FE models(L/R ratio upto 200)to determine SIFM and FE models with shell281-Beam189(for stiffeners)can be used to determine GIFM.The developed FE models are vali-dated by comparing numerical results with experimental results published by Seleim and Roorda[25].By using both proposed FE models it is possible to predict the failure modes namely SIFM and GIFM,comparing their values of critical buckling pressures.The lower pressure value can indicate the possible failure mode.展开更多
基金The authors are grateful for the support provided by the National Natural Science Foundation for Distinguished Young Scholars of China(No.51825904).
文摘In the process of suction penetration of bucket foundations with inner compartments for offshore wind turbines,most researches focus on soil seepage failure and soil plugs,while the buckling of foundations is rarely investigated.Therefore,theoretical calculation methods for critical buckling pressures of the skirt and bulkheads of the bucket foundation are first presented according to the stability theory of a cylindrical shell and the small deflection theory of a thin plate,respectively.Furthermore,two types of models with and without considering the skirt-soil interaction are developed for the calculation of critical buckling pressure of the bucket foundation.Taking a practical project as an example,theoretical and numerical methods are used to obtain the critical buckling pressures of a bucket foundation.In this work,the theoretical method and the finite element model considering the skirt-soil interaction for calculating the critical buckling pressure of bucket foundations are firstly proposed.The results can help to optimize the design process of offshore wind turbine foundations and improve the safety of offshore wind power systems.
文摘Submarine pressure hulls,fire-tube boilers,vacuum tanks,oil well casings,submersibles,underground pipelines,tunnels,rocket motor casing,etc.,are some of the examples of thin cylindrical shell structures which collapse due to buckling under uniform pressure.To enhance the buckling strength of bare cylin-drical shells,one of the best solutions is to stiffen them with ring stiffeners.In this work in order to predict the shell instability failure mode(SIFM)and general instability failure mode(GIFM)FE models are generated and analysed using buckling analysis of general-purpose FE software ANSYS.The numeri-cal results obtained using FE analysis are compared with published analytical and experimental results.Hence in the present study effort s are taken to develop FE models to predict global and shell instability failure modes of externally ring stiffened cylindrical shells by using linear FE analysis.It is proposed to use full/half bare cylindrical shell FE models(L/R ratio upto 200)to determine SIFM and FE models with shell281-Beam189(for stiffeners)can be used to determine GIFM.The developed FE models are vali-dated by comparing numerical results with experimental results published by Seleim and Roorda[25].By using both proposed FE models it is possible to predict the failure modes namely SIFM and GIFM,comparing their values of critical buckling pressures.The lower pressure value can indicate the possible failure mode.
