超声动载荷下三维随机骨料混凝土的损伤

混凝土是一种由粗骨料与水泥砂浆组成的非均质复合材料。本研究利用APDL语言程序编写三维水泥混凝土骨料随机投放程序并导入ABAQUS中,同时赋予各相材料塑性损伤本构关系来研究混凝土动态加载下的破坏规律,运用超声波在混凝土破碎中的作用机理对混凝土动态损伤破坏过程进行模拟研究。结果表明:随着超声动态载荷的增大,粗骨料体积分数为40%的混凝土始终能够承受最大应力载荷;随着超声应力波幅值增大,混凝土在动载荷下的损伤值逐渐增大,且粗骨料体积分数为40%时,其抗损伤能力最优;当粗骨料最大粒径逐渐增大,或者当粗骨料最小粒径增大,混凝土级配不合理导致性能不稳定,更易损伤破坏。

Damage of 3D Random Aggregate Concrete under Ultrasonic Dynamic Load

Concrete is a heterogeneous that is composed of coarse aggregate and cement mortar.The dynamic damage process of concrete was numerically simulated by the action mechanism of ultrasonic in concrete crushing in this paper.The random placement procedure of 3D concrete aggregate was prepared by APDL and introduced into ABAQUS,and the plastic damage constitutive relationship of each phase material was applied to study concrete damage law for dynamic loading.The numerical simulation results show that with the increase of ultrasonic dynamic load,the concrete with 40% coarse aggregate can always withstand the maximum stress load.As the amplitude of ultrasonic stress wave increases,the damage value of concrete under dynamic load increases gradually,and the damage resistance is optimal when the volume fraction is 40%.When the maximum particle size of the coarse aggregate gradually increases,or the minimum particle size of the coarse aggregate increases,the concrete grading is unreasonable,resulting in unstable performance and more vulnerable to damage.