基于双尺度理论优化混凝土力学性能的研究

Study on optimizing mechanical properties of concrete based on two-scale approach

为了实现混凝土抗压强度及弹性模量的精细化数值计算,基于双尺度理论建立了混凝土双尺度数值模型。该理论以有限元方法为载体,通过正交试验对混凝土抗压强度和弹性模量的影响因素进行了分析,并进行了力学试验验证。研究结果表明1)双尺度理论在混凝土数值模拟中的应用具有可行性,运用该方法的数值结果与试验结果差值在4.22%之内;2)混凝土的抗压强度受细观参数影响高度显著,其中砂浆性能对整体抗压强度的影响比例可达24.35%;3)混凝土的弹性模量受细观参数影响显著,其中粗骨料性能对整体弹性模量的影响比例可达6.55%。研究结果揭示了混凝土内部的粗骨料、砂浆、界面过渡区与孔隙对整体性能的影响效应,为优化和设计新型混凝土材料提供了新思路。

In order to realize the refined calculation of concrete compressive strength and elastic modulus,a two-scale numerical model of concrete was established based on the two-scale approach.The finite element method was taken as the carrier of this approach,the influencing factors of concrete compressive strength and elastic modulus were analyzed through orthogonal experiment,and the result was verified by mechanical test.The results show that:1)the application of two-scale approach in numerical simulation of concrete materials is feasible,and the difference between the numerical results and the experimental results is within 4.22%;2)the compressive strength of concrete is significantly affected by meso parameters,and the influence proportion of mortar on the overall compressive strength is up to 24.35%;3)the elastic modulus of concrete is significantly affected by meso parameters,and the influence proportion of coarse aggregate on the overall elastic modulus is up to 6.55%.The effects of coarse aggregate,mortar,interface transition zone and pores in concrete on the overall performance is revealed through the research results,which provide new methods for the optimization and design of new concrete materials.