刚性弹侵彻混凝土的内摩擦模型分析

Analysis of internal friction model of concrete target penetrated by rigid projectiles

为了建立反映侵彻近区材料变形与破坏特性的侵彻深度工程计算模型,基于地质类材料侵彻近区局部变形与破坏特点,在破碎区考虑介质的可压缩性和不可逆变形,在弹性区和裂纹区采用不可压缩介质描述。基于空腔膨胀理论构建了破碎区的运动学关系,利用裂纹失稳扩展的极值条件建立了混凝土侵彻阻抗的确定方法,得到了能够准确表征近区应变场与速度场的状态表达式,建立了锥形刚性弹对混凝土靶体的侵彻深度计算公式。通过算例计算,得到了不同工况下的计算结果且与试验结果吻合较好,验证了公式的正确性,说明所建模型可用于内摩擦型地质类材料的侵彻工程计算。

In order to establish a penetration depth engineering calculation model which can reflect the material deformation and damage characteristics of penetration near zone,based on the deformation and damage characteristics of the penetration near zone,the compressibility and irreversible deformation in crushing zone were taken into account and concrete considered to be incompressible in elastic and cracked zones.The kinematics realtions of the comminuted zone,based on the cavity-expansion theory,were established.The calculation method for the impedance of concrete was proposed by using the extremum condition of unstable propagation of cracks and the states of strain filed and velocity field were also deduced.Furthermore,the penetration depth calculation equation of conical rigid projectile penetrating into concrete target was obtained.The calculations for projectiles penetration under different conditions were carried out and the results compared with other available data to verify the validity of the presented equation.The applicability of the presented model in engineering calculation of geoloical materials penetration was demonstrated.