混凝土材料动态间接拉伸试验的数值模拟

发布时间：2018-06-06 22:14

本文选题：SCB实验 + BD实验　；参考：《合肥工业大学学报(自然科学版)》2017年08期

【摘要】：文章采用有限元软件ANSYS/LS-DYNA对冲击荷载作用下的半圆弯曲(semi-circular bending,SCB)实验和巴西圆盘(Brazilian disc,BD)实验进行了数值模拟;试样分别采用线弹性和混凝土Holmquist-JohnsonCook(HJC)动态本构2种模型,对2种动态间接拉伸试验中沿用静态线弹性理论计算抗拉强度的误差进行了分析。模拟结果表明:当SCB实验弧形垫块角度α在15°~25°,试样直边加载支座间距L与试样直径D的比值L/D在0.6~0.8,圆棒垫条半径r在0.004~0.006m范围内,BD实验弧形垫块角度β在18°~24°范围内,2种实验方法用静态弹性理论计算动态抗拉强度的最大误差均不超过9.8%,且2种本构模型模拟结果的误差不超过2%;冲击载荷作用下,SCB实验中试样起裂点始终为直边中点,而BD实验中试样起裂点不固定;在相同的加载情况下,SCB实验中试样的最大拉应力与最大压应力的比值显著大于BD实验,因此SCB实验更适合混凝土等脆性材料动态间接抗拉强度的测量。
[Abstract]:The finite element software ANSYS/LS-DYNA is used to simulate the semicircular bending (semi-circular bending, SCB) experiment under the impact load and the Brazil disk (Brazilian disc, BD) experiment. The sample adopts 2 models, linear elastic and concrete Holmquist-JohnsonCook (HJC) dynamic constitutive, to the 2 dynamic indirect tensile tests. The error of tensile strength calculated by the static linear elastic theory is analyzed. The simulation results show that when the angle of the SCB experimental arc pad is 15 ~25 degrees, the ratio of the distance L to the specimen diameter D is L/D at 0.6~0.8, the radius r of the circular rod pad is within the 0.004~0.006m range, and the BD experimental arc pad angle beta is within the range of 2 degrees in the range of 2 degrees. The maximum error of the dynamic tensile strength calculated by the static elastic theory is not more than 9.8%, and the error of the simulation results of the 2 constitutive models is not more than 2%. Under the impact load, the crack point of the sample is always the middle point of the straight edge in the SCB experiment, and the crack point of the sample is not fixed in the BD experiment; in the same loading condition, the sample in the SCB experiment The ratio of the maximum tensile stress to the maximum compressive stress is significantly greater than that of the BD experiment, so the SCB experiment is more suitable for measuring the dynamic indirect tensile strength of brittle materials such as concrete.
【作者单位】：合肥工业大学土木与水利工程学院;
【分类号】：TU528

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