Study On Impact Performance Of Glass Fiber Reinforced Plastic Thin-walled Tubes And Flexible PDMS

Split Hopkinson pressure bar(SHPB)testing is widely applied in the study of the structure of the shock resistance and dynamic mechanical behavior of materials under high strain rate is one of the classical experiment method in this paper,using SHPB experiment method of glass fiber reinforced plastic fiber thin wall tube(GFRP)tube and flexible base PDMS on shock compression experiment,respectively from the Angle of structure and material of GFRP tube shock resistance and high strain rate under the dynamic mechanical behavior of flexible base PDMS is analyzed.In this paper,we utilized Hopkinson pressure bar system to explore the impact resistance,deformation and failure mode,and dynamic response of GFRP thin–walled tube with different wall thickness and shape.Experimental results proved that the circular tubes possessed higher dynamic tangent modulus and better impact resistance while the square tubes exhibited more superior energy absorption property.In addition,those performances can be improved with thicker wall.Compared to other traditional aluminum alloy tubes,GFRP tubes showed better energy absorption capability.Secondly,the dynamic mechanical properties and dynamic response of flexible PDMS materials are investigated by SHPB experiment and finite element simulation.The strain rate effect,thickness effect,dynamic deformation process,stress wave velocity and velocity/displacement/acceleration responses are analyzed.The results show that the stressstrain curves of flexible PDMS has a certain stress hysteresis zone.The ultimate strength and corresponding strain,wave velocity,tangent modulus and velocity/displacement/acceleration responses all show significant strain rate effect.The stress wave velocity has three stages: decrease/increase/decrease.In addition,the dynamic response of flexible PDMS is quite different from that of traditional solid materials.In the initial stage of response,the responses of displacement,velocity and acceleration in different directions are weak;in the mid-term,the responses in all directions are obviously increased.In the loading direction,the velocity reaches its peak value in early time,and then enters the platform stage;and the acceleration response tends to be stable in the mid-response period.In the non-loading direction,the velocity and acceleration waveforms have obvious oscillation phenomenon.