The concept of cutting platform is proposed and realized based on the latest two step automated tape laying (Two step ATL)technology,which separates prepreg cutting process from tape laying to improve productivity for...The concept of cutting platform is proposed and realized based on the latest two step automated tape laying (Two step ATL)technology,which separates prepreg cutting process from tape laying to improve productivity for large parts with small features.Two step ATL is more efficient than conventional layup because ply patches are pre cut in a separate operation.The concept of the prepreg tape cutting experimental platform with two cutters is introduced.Further,based on the automatic tape laying trajectory planning software,a two cutter cutting algorithm is proposed.Cutting experiments are reported to validate both the concept of cutting platform and cutting algorithm.展开更多
Jacket cutting operation is one of the most complicated and highest risk operations in the process of decommissioning offshore piled platform, the security and stability of which must be assured. In this paper, the cu...Jacket cutting operation is one of the most complicated and highest risk operations in the process of decommissioning offshore piled platform, the security and stability of which must be assured. In this paper, the current research on offshore structure removal and jacket cutting is introduced, on the basis of which the types of load along with the load calculation method are determined. The main influences on the stability of a jacket in cutting are analyzed. The experiment test plan is drawn by using orthogonal testing method, and the formula of critical load during the cutting procedure is deduced by differential evolution algorithm. To verify the method and results of this paper, an offshore piled platform to be decommissioned in the South China Sea is taken for an example, and the detailed schedule for jacket cutting is made with the three-dimensional finite element model of the jacket established. The natural frequency, stress, strain and stability of the jacket during cutting process are calculated, which indicates that the results of finite element analysis agree well with that of the deduced formula. The result provides the scientific reference for guaranteeing the safety of jacket in cutting operation.展开更多
基金supported by the National Science and Technology Major Project(No.2016ZX04002-005)
文摘The concept of cutting platform is proposed and realized based on the latest two step automated tape laying (Two step ATL)technology,which separates prepreg cutting process from tape laying to improve productivity for large parts with small features.Two step ATL is more efficient than conventional layup because ply patches are pre cut in a separate operation.The concept of the prepreg tape cutting experimental platform with two cutters is introduced.Further,based on the automatic tape laying trajectory planning software,a two cutter cutting algorithm is proposed.Cutting experiments are reported to validate both the concept of cutting platform and cutting algorithm.
基金financially supported by the National Basic Research Program of China(973 Program,Grant No.2011CB013702)the National Natural Science Foundation of China(Grant No.51379214)the National High Technology Research and Development Program of China(863 Program,Grant No.2008AA092701-3)
文摘Jacket cutting operation is one of the most complicated and highest risk operations in the process of decommissioning offshore piled platform, the security and stability of which must be assured. In this paper, the current research on offshore structure removal and jacket cutting is introduced, on the basis of which the types of load along with the load calculation method are determined. The main influences on the stability of a jacket in cutting are analyzed. The experiment test plan is drawn by using orthogonal testing method, and the formula of critical load during the cutting procedure is deduced by differential evolution algorithm. To verify the method and results of this paper, an offshore piled platform to be decommissioned in the South China Sea is taken for an example, and the detailed schedule for jacket cutting is made with the three-dimensional finite element model of the jacket established. The natural frequency, stress, strain and stability of the jacket during cutting process are calculated, which indicates that the results of finite element analysis agree well with that of the deduced formula. The result provides the scientific reference for guaranteeing the safety of jacket in cutting operation.
