细观结构及加载速率对混凝土抗压特性影响的数值试验研究

Numerical experiment research of microstructure and loading rate affect on concrete compressive property

为了研究动荷载作用下混凝土材料的力学行为,通过随机数学方法建立细观混凝土随机骨料模型,得出动荷载作用下试件的荷载-位移曲线和损伤破坏图;与同尺寸的CT实时扫描试验的荷载-位移曲线和CT扫描断面图进行对比验证,得出以荷载-位移曲线的峰值强度作为细观混凝土试样的破坏强度。对4种尺寸相同,骨料位置不同的试件分别进行了5种不同速率的加载,结果表明随着加载速率的提高,混凝土的强度也在提高,加载速率提高到3倍时,其峰值强度提高了约21%,两者并不是同比例增长;同时,得出骨料位置的变化对混凝土的动强度具有一定的影响;通过对试件施加不同的惯性力和弹性参数,得到两者和混凝土动强度之间的关系。

In order to study the mechanical behavior of concrete material under the dynamic loading,through established the microscopic concrete randomly aggregate model,the load-displacement curves and damage failure diagram of the specimen which under dynamic load were obtained.A Contrastive study of numerical simulation and CT real-time scanning tests.The peak intensity of the load-displacement curves as the specimen failure strength was obtained.Four specimens of the same size,which have the different aggregate position,were carried out five different rates.The results showed that when the loading rate improving,the concrete strength was also improving.Loading rate increased to 3 times,at the same time,the peak intensity increased by about 21%.They were not the same growth of proportion.Meanwhile,found that different aggregate position under the condition of the same mix proportion had a certain effect on concrete strength.According to apply different inertial force and elastic parameters on the specimen,obtained the relationship between the specimen and them.