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在混凝土侵彻分析中,通常将混凝土等效成各向同性的均匀介质,然后通过宏观或细观的本构关系控制混凝土在冲击载荷作用下的变形行为.混凝土的均匀化解决了大量的工程实际问题,但不能揭示混凝土的变形和失效的物理机制.细观上,由于骨料等的存在,混凝土是非均匀材料.这种非均匀性可能对弹靶侵彻响应产生影响.要准确分析这种影响,分析模型必须考虑混凝土的细观结构.常见的细观模型将混凝土等效成三相复合材料,即砂浆、骨料砂浆与骨料间的粘结带.论文将混凝土等效成由砂浆和骨料组成的两相复合材料,并用界面强度替代粘结带,并综合应用VB和AutoCAD开发了混凝土骨料随机分布的三维几何模型建模方法,利用有限元前处理软件离散了几何模型,建立了侵彻分析的“数值混凝土”靶体模型,初步分析了骨料的随机性、骨料砂浆之间的界面强度对正侵彻响应的影响,初步分析表明:随机分布的骨料给弹体施加非对称载荷,从而影响弹的侵彻轨迹,这在均匀化模型中无法实现;弹体的剩余速度随骨料与砂浆界面连接强度的增加而降低.
In concrete penetration analysis, the concrete is usually equivalent to an isotropic homogeneous medium, and then the deformation behavior of the concrete under impact load is controlled by the macroscopic or microscopic constitutive relationship. The homogenization of the concrete solves a large number of engineering The practical problem, however, can not reveal the physical mechanism of concrete deformation and failure.Most, concrete is heterogeneous due to the presence of aggregates, etc. This non-uniformity may have an impact on the response of the projectile’s penetration.To accurately analyze this , The analysis model must consider the mesostructure of concrete.The common mesoscopic model will make the concrete equivalent to three-phase composite material, namely, the mortar, aggregate mortar and aggregate adhesive tape.This paper equivalent to the concrete Mortar and aggregate, and the bonding strength was replaced by the interfacial strength. A three-dimensional geometric model modeling method of random distribution of concrete aggregates was developed by using VB and AutoCAD. The finite element preprocessing software was used to discretize the geometric model , A model of “numerical concrete” target for penetration analysis was established. The randomness of aggregate, the interfacial strength of aggregate mortar, The initial analysis shows that the random distribution of the aggregate exerts asymmetric load on the projectile, which affects the trajectory of the projectile, which can not be achieved in the homogenization model. The residual velocity of the projectile varies with the interface of aggregate and mortar Strength increases and decreases.