基于随机骨料模型的混凝土抗侵彻性能的数值模拟研究

发布时间：2018-01-20 23:14

本文关键词： 随机骨料混凝土侵彻数值模拟　出处：《太原理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：混凝土被广泛应用于建筑、桥梁以及防护结构等,由于混凝土在防护结构中应用的重要性,混凝土侵彻的研究受到广泛专注。混凝土材料的宏观力学性能主要由其细观结构的力学性质直接或间接的决定,因此,混凝土细观力学性能及其结构特点成为研究混凝土力学性能的主要内容之一。混凝土的细观结构一般认为是由水泥砂浆、骨料、及其接触的粘结界面组成的三相复合材料,其结构性能表现的很复杂,目前混凝土侵彻模拟一直采用实体模型建模,并赋予其HJC本构模型进行模拟。然而,混凝土实体模型不能完全表现其性能的复杂性,模拟结果与实际相差较大,导致数值模拟结果的可信度降低。由于混凝土内部的骨料一般是不同形状的石子,因而把骨料模拟为随机三维多面体,更加接近实际。目前基于随机骨料的混凝土研究主要集中在二维领域,三维的骨料模型还不够完善。随机骨料的研究从最初的二维圆形、椭圆形到正多边形、随机多边形,从三维球体、椭球体到随机多面体。通过对随机骨料的研究,对混凝土细观结构的性能更加了解。本文主要工作如下:1.懫用Matlab软件,通过随机函数产生随机数的思想,提出二维随机骨料的生成和投放方法,在此基础上,编写三维随机骨料的生成程序,并生成不同体积率的凸多面体骨料;2.提取不同体积率凸多面体骨料的参数信息,采用有限元软件生成三维随机骨料模型,利用有限元软件+进行网格划分,建立基于三维随机骨料的混凝土模型。3.主要建立了球头弹、平头弹、不同CRH卵形弹,以及不同侵彻角度的卵形弹对基于随机骨料的混凝土靶体的侵彻模型,研究不同侵彻因素对混凝土靶体抗侵彻性能的影响。4.采用有限元软件LS-DYNA对侵彻模型进行求解计算,对计算结果进行分析。通过球头弹和平头弹侵彻混凝土靶体的侵彻深度、剩余速度、加速度-时间曲线、位移-时间曲线等,可知混凝土靶体抗平头弹侵彻的性能较好。通过不同CRH卵形弹侵彻混凝土靶体的结果,可知随着CRH的增大,混凝土靶体抗侵彻的性能越差。对于不同侵彻角度,随着侵彻角度的增大,混凝土靶体抗侵彻性能越好。
[Abstract]:Concrete is widely used in buildings, bridges and protective structures, because of the importance of concrete in the application of protective structures. The study of concrete penetration has been widely focused. The macroscopic mechanical properties of concrete materials are mainly determined directly or indirectly by the mechanical properties of its meso-structure. The meso-mechanical properties of concrete and its structural characteristics have become one of the main contents of studying the mechanical properties of concrete. The meso-structure of concrete is generally considered to be composed of cement mortar and aggregate. The structure and performance of the three-phase composite composed of bonded interface and its contact are very complicated. At present, the concrete penetration simulation has been modeled by solid model and given its HJC constitutive model to simulate. However. The concrete solid model can not completely express the complexity of its performance, and the simulation results are different from the actual results, which leads to the reduction of the credibility of the numerical simulation results. Because the aggregate inside the concrete is generally different shapes of stone. Therefore, the aggregate is simulated as a random three-dimensional polyhedron, which is closer to the reality. At present, the research of concrete based on random aggregate is mainly focused on the two-dimensional field. The three-dimensional aggregate model is not perfect. The research of random aggregate from the initial two-dimensional circular, elliptical to regular polygon, random polygon, from three-dimensional sphere. From ellipsoid to random polyhedron. Through the study of random aggregate, the performance of concrete mesoscopic structure is better understood. The main work of this paper is as follows: 1. Use Matlab software. Based on the idea of generating random number by random function, the method of generating and dropping two-dimensional random aggregate is put forward. On this basis, the program of generating 3D random aggregate is written, and the convex polyhedron aggregate with different volume rate is generated. 2. Extracting the parameter information of convex polyhedron aggregate with different volume rate, using finite element software to generate three-dimensional random aggregate model, and using finite element software to mesh. The concrete model based on 3D random aggregate is established. 3. The spherical projectile, flat projectile and different CRH oval projectile are established. And the penetration model of concrete target based on random aggregate with different penetration angles. The influence of different penetration factors on the penetration resistance of concrete target is studied. 4. The finite element software LS-DYNA is used to solve the penetration model. Through the penetration depth, residual velocity, acceleration time curve, displacement time curve and so on. Through the results of different CRH oval projectiles penetrating into concrete target, we can know that with the increase of CRH, the penetration resistance of concrete target is better. The worse the anti-penetration performance of concrete target is, the better the anti-penetration performance of concrete target is with the increase of penetration angle.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TJ410;TU528

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