| With the development of high-tech weapons,protective materials and protective structure are facing more severe challenges in resisting the penetration of high-tech precision guided weapons.Due to its excellent mechanical properties and resistance to penetration,functionally graded cement based composites(FGCC)play an important role in the field of protection engineering.In this paper,the effects of steel fiber and high strength coarse aggregate on the staticmechanical properties of ultra-high performance cement based composites are discussed.The compressive strength and flexural strength of ultra-high performance cement based composites with 1.5%volume fraction steel fiber and perfused ceramic balls were 187.4MPa and 13 MPa respectively.Functionally graded concrete targets with double and triple layers structure were prepared with optimised ultra-high performance cement-based composite materials.Repeated penetration tests were carried on FGCC for two and three times of impacts.For double-layer functional graded target SFG2,its first time penetration depth decreases 79%than that of C50 concrete and its second time penetration depth decreases 53%.The first penetration depth of the functionally graded target TFG3 with the three layer structure is 61mm which decreases 65%than that of C50 concrete and the damage of its front face is smallest.After multiple penetration,there is no spalling on the rear sides of FGCC targets.Penetration of FGCC target with different distance between coarse ceramic aggregates was simulated using finite element software of Autodyn.Penetration depth and crater diameter increased with the increase of the distance between ceramic aggregates.The penetration depth and crater diameter by simulation of SPH algorithm were very closed to the experimental results when the distance between ceramic aggregates is 4mm.The penetration process and dynamic response of FGCC target were finally uncovered by combining of simulation and experiment. |
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