混凝土三维随机参数化骨料模型

A three-dimensional model for concrete with random parameterized irregular aggregate

在三维情形下,基于参数曲面的自由变形技术,将混凝土骨料及黏结界面,用确定的、形式统一的参数方程予以表示,建立了混凝土随机参数化骨料数学模型;以骨料为卵石的混凝土为例,给出了级配、配合比等都可控制的骨料含量超过50%的随机混凝土数值试样,提出了用参数映射法对试件进行有限元网格剖分的方法。该数学模型较好地描述了骨料、砂浆与黏结界面组成的三维三相复合结构形式,为进一步在细观层次上研究和确定混凝土的动力学性能打下了基础。

At the mesoscopic level, concrete is considered as the three-phase non-homogeneous composite materials composed of coarse aggregate, cement mortar and bonded interface between them. In the three-dimensional case, based on the technique of free-form deformation for parametric surfaces, the every aggregate and interface is expressed by a defined and unified parametric equation, and then the concrete random parameterized aggregate model has been established. When the concrete aggregate is gravel, the model gives a concrete random numerical structures （more than 50% aggregate content） with the controllable grade, content and rate of composite. The finite element mesh generate method is proposed by use the parameter mapping method, and shows an advantage in describing three-dimensional three-phase composite materials formed the aggregate, mortar and bonding interface, which presents a theoretical basis for further research on dynamic mechanical performance of concrete in the mesoscopic level.