连续纤维增强高孔隙复合材料的抗侵彻性能研究

A study of anti-penetration properties of continuous fiber-reinforced high-porosity composites

为开展连续纤维增强高孔隙复合材料的侵彻防护性能,首先,用二级轻气炮发射Q235钢质弹丸,对连续纤维增强高孔隙复合材料开展弹道侵彻实验,计算了弹道极限,归纳和分析了其损伤的形态和模式,并将这种复合材料的侵彻防护性能与其他材料进行了比较;然后,对弹道侵彻连续纤维增强高孔隙复合材料进行了数值模拟,比较了剩余速度、损伤的形态和范围,模拟结果与实验结果吻合较好;进而通过观察有限元模拟的弹孔形态、应力分布和损伤分布等方式,对侵彻过程的损伤机理进行了分析。研究结果可为复合材料在防热、冲击防护与承受外载荷等多功能一体化的应用提供参考依据。

It is of great scientific significance and application value to study the anti-penetration performance of continuous fiber-reinforced high-porosity composites.First,the ballistic penetration experiments of 20 mm thick continuous fiberreinforced high-porosity composites were carried out by using two-stage light gas gun firing Q235 steel projectiles of diameter 4.5 mm.Based on the analysis of the initial and final velocities of bullet penetration,the ballistic limit of the material is obtained.By observing the damage patterns of the target plate,these patterns are divided into three types from low to high according to the initial velocity of the projectiles:back-crack type,back-burst type and penetrated type.The anti-penetration performance of this composite material is compared with other materials by specific energy absorption,showing that the antipenetration performance of the composite against low-speed penetration up to 600 m/s is better than those of steel,aluminum,Kevlar and glass fiber composite.Then,an orthogonal anisotropic continuum damage constitutive model is proposed for the continuous fiber-reinforced high-porosity composites.This constitutive model is written as a subroutine and embedded in the finite element software by secondary development.On this basis,the finite element simulations of ballistic penetrations of continuous fiber reinforced high-porosity composites are conducted.The validity of the constitutive and finite element models is verified by comparing the final velocity,ballistic limit and damage range of the back surface obtained from experiment and simulation.Furthermore,the damage mechanism of the penetration process is analyzed by observing the shape of the bullet hole,stress distribution and damage distribution obtained from the finite element simulation.The results show that the formation of the bullet hole during the penetration of spherical projectile is caused by shear damage,the debonding of fiber and matrix is caused by the combined action of compression and shear,the delamination damage of the target plate is caused by the tension wave created by the reflection of compression wave,and the fiber breakage belongs to tension damage.Besides,the kinetic energy,internal energy and their proportion to the kinetic energy change of the bullet are compared with the initial velocity.It is pointed out that most of the kinetic energy of the projectile is transformed into the kinetic energy of the fragment of target plates and the plastic deformation energy of the projectile.The research results provide a reference for the multifunctional integration of these composite materials in heat protection,penetration protection and load bearing.