This paper examines a scheme to optimize the multiple winding angles of reinforced thermoplastic pipes(RTPs)under internal and external pressures.To consider the nonlinear mechanical behavior of the material under cha...This paper examines a scheme to optimize the multiple winding angles of reinforced thermoplastic pipes(RTPs)under internal and external pressures.To consider the nonlinear mechanical behavior of the material under changes of winding angle due to deformation,we use three-dimensional(3D)thick-walled cylinder theory with the 3D Hashin failure criterion and theory of the evolution of damage to composite materials,to formulate a model that analyzes the progressive failure of RTPs.The accuracy of the model was verified by experiments.A model to optimize the multiple winding angles of the RTPs was then established using the model for progressive failure analysis and a multi-island genetic algorithm.The optimal scheme for winding angles of RTPs capable of withstanding the maximum internal/external pressure was obtained.The simulation results showed that the ply number of the reinforced layer has a prominent nonlinear effect on the internal and external pressure capacity of the RTPs.Compared with RTPs with a single angle of±55°,the multiple winding angle overlay scheme based on the multi-angle optimization model improved the internal and external pressure capacity of the RTPs,and the improvement in the external pressure capacity was significantly better than the internal pressure carrying capacity.展开更多
基金This research was funded by the National Key Research and Development Program of China(No.2016YFC0303800)the National Natural Science Foundation of China(No.51579245).
文摘This paper examines a scheme to optimize the multiple winding angles of reinforced thermoplastic pipes(RTPs)under internal and external pressures.To consider the nonlinear mechanical behavior of the material under changes of winding angle due to deformation,we use three-dimensional(3D)thick-walled cylinder theory with the 3D Hashin failure criterion and theory of the evolution of damage to composite materials,to formulate a model that analyzes the progressive failure of RTPs.The accuracy of the model was verified by experiments.A model to optimize the multiple winding angles of the RTPs was then established using the model for progressive failure analysis and a multi-island genetic algorithm.The optimal scheme for winding angles of RTPs capable of withstanding the maximum internal/external pressure was obtained.The simulation results showed that the ply number of the reinforced layer has a prominent nonlinear effect on the internal and external pressure capacity of the RTPs.Compared with RTPs with a single angle of±55°,the multiple winding angle overlay scheme based on the multi-angle optimization model improved the internal and external pressure capacity of the RTPs,and the improvement in the external pressure capacity was significantly better than the internal pressure carrying capacity.
