Anti-penetration Performance Of 3-D Braid Fiber Reinforced BMSC Mortar And Concrete Composite Target

3D braided fiber is a composite material that is made of reinforced phase of cement matrix.It has more significant bending,tensile and toughening effects than traditional fiber concrete.It has a bright application foreground of protection engineering.Research on 3D braided fiber reinforced cement(anti-penetration performance of 3D-Textile Reinforced Cement Mortar,3D-TRCM)composites and their composite structures with concrete have important theoretical significance and engineering value.In this paper,Basic Magnesium Sulfate Cement(BMSC)is used as the cementing material,and3 D braided basalt fiber and glass fiber are used as the reinforcing material.Two types of 3D-TRCM composite materials devised initially,and their compression and tensile strength are further researched.The static mechanical properties such as bending resistance and flexural strength were discussed.The effect of 3D braided fiber on the static mechanical properties of BMSC mortar was strengthened and toughened.Secondly,two types of 3D-TRCM composites with different structures and concrete(3D-TRCM / C)composites were devised.The target body were tested with a pierced tungsten alloy projectile for real bullet penetration.The anti-penetration and protection performance of the3D-TRCM / C composite target was studied.The 3D-TRCM on the front and back elastic surfaces of the composite target were obtained.The composite material is contributed to improve the penetration damage resistance of the target top,pitting resistance,penetration resistance and target bottom anti-seismic performance.Finally,the LS-DYNA finite element software is used to inject the3D-TRCM / C composite target.Numerical simulations were performed under the working conditions,and the model parameters of the JOHNSON HOLMQUIST CONCRETE material for the 3D-TRCM composite and the 3D-TRCM / C composite target were obtained.Based on this,the 3D woven fiber reinforced BMSC mortar and concrete were further studied.Research on the relationship between the target body together with the penetration ability of the anti-penetration velocity,the thickness between layers of composite material,the structural strength of the concrete 3D-TRCM.The main contents and conclusions of the full text are as follows:(1)3D braided fibers have a toughening effect on BMSC mortar.Basalt fiber 3D-TRCM test pieces have 120.0% and 18.2% higher splitting tensile strength on the front and sides than BMSC mortar,and glass fiber 3D-TRCM test pieces have 158.2% and 36.4% higher splitting tensile strength on the front and side than BMSC mortar.Due to the high fiber content in the unit volume of 3D braided fibers,it is difficult to pour the 3D-TRCM composite material during preparation.The compressive strength of the basalt fiber and glass fiber 3D15-TRCM specimens was reduced by 7.9%and 54%,and the basalt fiber and glass fiber 3D90-The compressive strength of the TRCM test piece was reduced by 16.5% and 36.8%.The modulus of elasticity of the 3D-TRCM composite material is much lower than that of ordinary concrete,and the Poisson’s ratio is much higher than that of ordinary concrete.The 3D woven fiber plays a good role in bridging cracks in the cement mortar matrix.It shows that the toughening effect of 3D-TRCM composites is obvious;3D braided fibers can significantly improve the bending resistance of cement mortar,and the bending strength of3D15-TRCM is 87.0% and 14.0% higher than that of BMSC mortar.Basalt fibers and glass fibers The bending strength of 3D90-TRCM specimens is 21.7% and 24.9% higher than that of BMSC mortar.(2)The anti-penetration performance of the 3D-TRCM / C composite target was researched through a live ammunition penetration test.The damage results of the target after the ammunition penetration showed that the 3D-TRCM / C composite target had a 3D-TRCM composite material that placed on the target’s elastic surface can effectively reduce the target’s crater diameter and pit volume,greatly limit the penetration depth of the target,and significantly reduce the damage of the target to the target.The 3D-TRCM composite material is placed on the elastic surface of the bottom of the target,which can reduce the collapse and damage of the target,inhibit the concrete from breaking and spalling when the target is penetrated,and play the role of engineering protection.In the live ammunition test,the composite target body with the 3D-TRCM composite material which placed on the bottom of the target did not produce a collapse pit,and the bare magnesium sulfate concrete target of the same proportion and the same size produced a significant shock after the penetration of the same bullet velocity.(3)By establishing the same numerical simulation conditions as the real bullet penetration test,comparing the numerical simulation results of the two types of targets with the real bullet penetration results,the 3D-TRCM was verified by the bullet velocity time history curve and the bullet negative acceleration time history curve.The anti-penetration protection effect of the composite material on the target body is basically consistent with the results of the live ammunition penetration test.(4)Through numerical simulations,the factors affecting the anti-penetration performance of the two types of target structures with 3D-TRCM composites placed on the top and bottom of the target were calculated and studied.The analysis focused on the thickness of the 3D-TRCM layer and the impact of the bullet on the target.Research on influence of speed and strength of concrete layer.The results of numerical simulations show that:(1)The increase of the thickness of the 3D-TRCM layer can increase the penetration resistance of the projectile and reduce the pit area of ??the composite target.At the same time,in the two types of structures,the 3D-TRCM composite material placed on the elastic surface has better penetration resistance improvement effect than the 3D-TRCM composite material placed on the back-elastic surface structure.(2)The penetration depth deepens as the bullet speed increases.However,the increase in speed did not lead to the expansion of the crater of the3D-TRCM composite target,indicating that 3D-TRCM can inhibit the crater of the target as a ballistic surface.(3)As the strength of the concrete layer increased,the penetration depth of both of the naked target and the composite target decreases.In addition,the penetration depth of the 3D-TRCM / C composite target is shallower than that of a naked concrete target at the same strength condition.As the strength of the concrete layer increased,the strength of the concrete layer is C100,while depth of both of penetration the 3D-TRCM / C composite target and naked target is similar.Therefore,3D-TRCM composites can improve the anti-penetration performance of targets close to or lower than the strength of the material itself,and slightly improve the penetration depth of targets higher than its strength.In the structure where the 3D-TCRM composite material is placed on the back-elastic surface,when the strength of the concrete layer is low,the 3D-TRCM / C composite target body is more effective in suppressing the target bottom from collapsing and opening pits.The improvement of its anti-seismic effect tends to the naked target.