基于SPH方法的钢筋混凝土切削模拟研究

Simulation of reinforced concrete cutting based on SPH method

钢筋混凝土材料目前已得到广泛应用,但其加工切削过程十分复杂。为解决常规有限元模拟中网格变形尺寸有限的局限性,采用光滑粒子流体动力学(SPH)算法模拟研究金刚石磨粒对钢筋混凝土的切削破碎过程。在数值模拟中,根据金刚石出刃状态将其简化成方形、圆形2种磨粒,并以0.45 mm/ms的速度和0.1 mm的切削深度对钢筋、混凝土和不同组合的钢筋混凝土材料进行表面切削,分析不同情况下的基体碎屑形态特征、切削后基体材料表面形态变化、内部裂纹延伸变化以及磨粒切削面上的应力变化情况。模拟结果表明:SPH方法能够较好地模拟钢筋混凝土在切削过程中的裂纹扩展、碎屑形成和分离;磨粒在切削过程中受到间断性冲击后,会优先破坏混凝土和钢筋材料之间的连接强度,使2种材料逐渐分离,且磨粒以面切削方式进行加工时,相较于点切削方式,能够形成更大的破碎区域。

Reinforced concrete structure has been widely applied in modern society,while its cutting process is very complicated.To solve the inaccurate problem due to grid deformation in conventional finite element method,smoothed particle hydrodynamics(SPH)particle algorithm was adopted to simulate the cutting and breaking processes of reinforced concrete by diamond abrasive particle.According to their possible protrusion states of diamonds on tools’working surface,diamonds were simplified as square and circular abrasives respectively.Then,the abrasives performed surface cutting on steel,concrete,and different combinations of reinforced concrete materials at a cutting speed of 0.45 mm/ms and a cutting depth of 0.1 mm.The morphological characteristics of cutting chips,the morphological change of the working pieces surface after cutting,the change of crack extension within the working pieces,as well as the stress change on the cutting surface of two kinds of abrasives were analyzed.The simulation results indicate that the SPH method can simulate the crack propagation,the chip formation and the materials separation during the cutting process.The intermittent impact on abrasives in the cutting process will preferentially destroy the connection between the two materials which can be gradually separated to each other.Besides,in the surface cutting type of square abrasive there can form a larger broken area than that in the point cutting type of circular abrasive.