To reach a compromise between short acquisition time and excellent detection probability for the high-dynamic binary offset carrier (BOC) signal, an overall algorithm based on discrete polynomial-phase transform (DPT)...To reach a compromise between short acquisition time and excellent detection probability for the high-dynamic binary offset carrier (BOC) signal, an overall algorithm based on discrete polynomial-phase transform (DPT) and partial matching filter (PMF)-fast Fourier transform (FFT) algorithm is given. The high order items of received signals are removed by the method of DPT, and the PMF-FFT algorithm is redesigned for the BOC signal. The simulation experiments and theoretical analyses verify that the improved algorithm has attained improvement in acquisition performance. ? 2016 Beijing Institute of Aerospace Information.展开更多
In this work,a bond-based peridynamics(PD)model was built to analyze the dynamic fracture of shale material.Both the the convergence studies and the result of dynamic crack propagation were presented.As well-known,cra...In this work,a bond-based peridynamics(PD)model was built to analyze the dynamic fracture of shale material.Both the the convergence studies and the result of dynamic crack propagation were presented.As well-known,crack propagation,aggregation,and bifurcation play an critical role in the failure analysis of brittle materials such as shale.The dynamic crack propagation and branching analysis of shale by using the PD method were discussed.Firstly,the valid and accuracy of the PD model for the rock materials was verified by comparing with the existed numerical results.Secondly,we discussed the convergence both with uniform grid refinement(m-convergence)and decreasing the peridynamics horizon(δ-convergence).Then the shale material with two pre-crack under uniaxial compression using the present PD model were discussed,and the influence of the different angle of flaws on the behavior of crack propagation was also analyzed.The results shows that both the loading conditions and the angle of flaws can influences the crack propagation in shale.展开更多
基金supported by the National Natural Science Foundation of China(6127509961371164)+2 种基金the Natural Science Foundation of Chongqing(CSTC2012JJA40008)the Research Project of Chongqing Educational Commission(KJ120525KJ130524)
文摘To reach a compromise between short acquisition time and excellent detection probability for the high-dynamic binary offset carrier (BOC) signal, an overall algorithm based on discrete polynomial-phase transform (DPT) and partial matching filter (PMF)-fast Fourier transform (FFT) algorithm is given. The high order items of received signals are removed by the method of DPT, and the PMF-FFT algorithm is redesigned for the BOC signal. The simulation experiments and theoretical analyses verify that the improved algorithm has attained improvement in acquisition performance. ? 2016 Beijing Institute of Aerospace Information.
基金This work was supported by the Natural Science Foundation of China(Nos.11472248,51708510,11872339)the Natural Science Foundation of Henan Province(No.182300410221).
文摘In this work,a bond-based peridynamics(PD)model was built to analyze the dynamic fracture of shale material.Both the the convergence studies and the result of dynamic crack propagation were presented.As well-known,crack propagation,aggregation,and bifurcation play an critical role in the failure analysis of brittle materials such as shale.The dynamic crack propagation and branching analysis of shale by using the PD method were discussed.Firstly,the valid and accuracy of the PD model for the rock materials was verified by comparing with the existed numerical results.Secondly,we discussed the convergence both with uniform grid refinement(m-convergence)and decreasing the peridynamics horizon(δ-convergence).Then the shale material with two pre-crack under uniaxial compression using the present PD model were discussed,and the influence of the different angle of flaws on the behavior of crack propagation was also analyzed.The results shows that both the loading conditions and the angle of flaws can influences the crack propagation in shale.
