混凝土三维参数化骨料模型的创建方法

THE APPROACH TO ESTABLISHING A THREE-DIMENSIONAL PARAMETERIZED AGGREGATE MODEL FOR CONCRETE SIMULATION

在混凝土细观结构试件的模拟中,为了降低骨料之间的相互排斥性,缩小骨料之间的空隙、提高骨料的含量、加快试件的创建速度,提出混凝土三维参数化骨料模型的创建方法.该方法充分利用骨料的参数方程,给出了骨料内外的判别方法,以及点到骨料的距离的快速计算方法和误差估计,可以有效地控制骨料之间的空隙,从而提高试件中骨料的含量.实验表明这是一个有效的方法,可以按二级配生成含不规则骨料体积达55%以上的试件,完全达到了实际混凝土的骨料含量要求,为对混凝土进行细观力学分析提供了创建数值模型的方法.

In the numerical simulation of concrete specimen at meso-level,to reduce the repellency and distances between aggregates as well as to improve the content of the aggregates and the computational speed of generating the specimen, a method for establishing a three-dimensional parametric aggregates mod- el is suggested. This method makes use of the parametric equation of the aggregates,presents a rule to de- termine whether a spatial point is inside the aggregates or not. Moreover,the fast algorithm for computing the distance between the spatial points and the generated aggregates is presented and the corresponding er- ror analysis is given. Based on these, the space between aggregates can be controlled and therefore, the con- tent of aggregates in the specimen can be improved. Numerical results show that this method is effective, with which the concrete specimen with more than 55% irregular aggregates in volume can be generated ac- cording to two gradation. This is very close to content of aggregates in practical concrete.