SHPB Impact Constitutive Relationship Of Composite Ceramsite Concrete

All-lightweight concrete(ALWC)and lightweight concrete substituted by part of fine aggregate(LWCSCA)have the characteristics of qualitative light,high strength,Earthquake and refractory.Mixed with different kinds of fiber,it can effectively improve the static and dynamic performance.Research on shock resistance of this material is not enough.In this paper,base on the previous study on the static performance of our research group,SHPB shock test are performed to study the impact properties and effect of strain rate of all-lightweight fiber concrete,lightweight fiber concrete stone ceramsite,SPUA-BR all-lightweight fiber concrete and SPUA-BR lightweight fiber concrete stone ceramsite.The ANSYS/LS-DYNA is used to numerically simulate the shock test of ALWC and LWCSCA.According to the difference between experimental results and numerical simulation results,the constitutive relation is improved and corrected..Specific work and research content are as follows:(1)Through the statics experiment of FRALWC and FRLWCSCA found that fiber can effectively improve the strength and toughness of concrete,based on the stress-strain curve in the view of energy analysis,various kinds of fiber can improve the peak characteristics,and can make the decline more gentle and longer;(2)When the bullet hit rate increased,it also increase included with the peak stress and fracture strain of concrete.Also,with the increase of the impact velocity the pieces of concrete have more and more,and gradually smaller.(3)Based on all the results from all the tests,it shows that both the peak strain and fracture strain of FRALWC and FRLWCSCA have a non-linear relationship with their effect of strain rate and fiber index.(4)The peak stress and peak strain of SUPA light aggregate concrete higher then FRALWC and FRLWCSCA,and they all increase with increased thickness of SPUA-BR.Blocks with SPUA-BR one side appear penetrating cracks,blocks with SPUA-BR two sides have intact appearance,withoutpenetrating cracks.(5)The result of numerically simulate on ANSYS/LS-DYNA is quite sililar to the result of test.And the peak stress of simulate higher then the test,because the simulate is proceed in ideal state all the time.(6)Considering the fiber enhancement effect,strain rate effect and the influence of fiber index,the HJC dynamic constitutive model has been modified eventually.