Research On Experiment Of Hydraulic Expanding Ring Technology Based On SHPB

The expansion ring test is an effective method to study the mechanical properties of materials under one-dimensional impact tensile loading.It is the basis of studying the fragmentation and fracture mechanism of solid materials under impact tensile loading.In this paper,an experimental technique of hydraulic expansion ring based on Hopkinson Hopkinson pressure?Split bar SHPB?was developed,and the dynamic tensile fracture test of ductile metal was carried out effectively.The ring was mainly subjected to circumferential tensile force during its expansion and satisfieed quasi one dimensional stress conditions.The process of ring expansion under the impact of water was obtained.The ultra-high speed photography.The radial velocity curve of ring was measured by laser Doppler velocimeter?VISAR?measurement.The pressure curve of water system was tested by hydraulic sensor.The debris of ring were completely recovered through the silica gel pad.Numerical simulation method was used to reproduce the process of water impacting the expanding ring.The simulation results showed that the influence of contact force between the ring and the device at the initial time under the experimental conditions,which can affect the expansion speed of the ring,could be neglected.The loading conditions of the piston were optimized by simulation,and the free expansion of the ring was realized.The dynamic tensile fracture test of typical ductile metals?1060-O aluminum?had been carried out by means of hydraulic expansion ring test technique.The statistical analysis of debris showed that the quality of ring debris conforms to the Weibull distribution,and the average size of debris agrees with the predicted trend of Grady-Kipp theory.The dynamic tensile fracture test of a ductile metal?1060-O aluminum?containing artificial defects showed that the geometric defects play a controlling role in the dynamic tensile fracture and tensile fragmentation.The greatest geometric imperfections were in the control of priority.The dynamic tensile fracture experiment of viscoelastic materials?PMMA?and brittle materials?Si O₂,quartz glass and Al₂ O₃ ceramics?had been effectively realized by the hydraulic expansion ring experimental technique.The experimental results showed that the hydraulic expansion ring experimental technique can carry out the dynamic tensile fracture test of the ductile and brittle materials,which provides a new experimental method for the dynamic tensile fracture research of the solid materials.