CAJ | 학술논문

采用刚性伺服试验机和声发射仪器,研究了预置三维裂隙间距对砂浆材料力学特性的影响,总结了含裂隙试件的破坏过程.综合分析单轴压缩应力-应变曲线和声发射数据可知,含三维裂隙试件的破坏主要由预置裂隙扩展、贯通造成,破坏过程可以分为微裂纹萌生、预置裂隙起裂、扩展、贯通几个基本阶段,试件最终破坏型式为单斜面剪切破坏.裂隙间距d与椭圆形裂隙长轴2c之比(d/2c)在0～1范围内,随着d/2c值增大,试件起裂应力σ_ i和峰值强度σ _p有降低的趋势.当d/2c值从1/3增至2/3时,σ _i和σ _p发生突降,可见此范围为影响强度的敏感区间.d/2c值为1的试件σ _i和σ_ p最低,相对完整(无预置裂隙)试件分别降低了22.48 %和18.60 %.裂隙间距不同的试件σ_ i和σ_ p之比变化范围为83.1 %～78.9 %,且随d/2c值增大,σ_ i / σ_ p有下降趋势.可见裂隙间距越大,从起裂应力到峰值应力的承载空间越大,这对工程实践有一定参考价值.
채용강성사복시험궤화성발사의기,연구료예치삼유렬극간거대사장재료역학특성적영향,총결료함렬극시건적파배과정.종합분석단축압축응력-응변곡선화성발사수거가지,함삼유렬극시건적파배주요유예치렬극확전、관통조성,파배과정가이분위미렬문맹생、예치렬극기렬、확전、관통궤개기본계단,시건최종파배형식위단사면전절파배.렬극간거d여타원형렬극장축2c지비(d/2c)재0～1범위내,수착d/2c치증대,시건기렬응력σ_ i화봉치강도σ _p유강저적추세.당d/2c치종1/3증지2/3시,σ _i화σ _p발생돌강,가견차범위위영향강도적민감구간.d/2c치위1적시건σ _i화σ_ p최저,상대완정(무예치렬극)시건분별강저료22.48 %화18.60 %.렬극간거불동적시건σ_ i화σ_ p지비변화범위위83.1 %～78.9 %,차수d/2c치증대,σ_ i / σ_ p유하강추세.가견렬극간거월대,종기렬응력도봉치응력적승재공간월대,저대공정실천유일정삼고개치.
The rigid serve-controlled test machine and acoustic emission equipment are used to study the influence of space between 3D-cracks on the mechanical feature of mortar material; and the failure process of samples with pre-existing cracks is concluded. The analysis of complete stress-strain curves and AE data indicates that sample failure is due to the propagation and coalescence of cracks. Failure process of samples with pre-existing cracks could be divided into the following stages: microcrack initiation, initiation of pre-existing cracks, crack propagation and crack coalescence. The failure pattern is shear failure along single inclined plane. When the ratio of cracks space d and length of elliptic crack long axis 2c ranging from 0-1, as the ratio grows, the initiation stress and maximum stress of samples reduce. With the ratio d/2c growing from 1/3 to 2/3, the initiation stress and maximum stress fall suddenly, showing that this space scope is the sensitive range. When the ratio d/2c =1, the initiation stress and maximum stress of sample fall 22.48 % and 18.60 % respectively corresponding to the sample without pre-existing cracks. The ratio of initiation stress to maximum stress of all different samples ranges from 83.1 % to 78.9 %. As the ratio d/2c grows, the ratio of initiation stress to maximum stress declines, which indicates that as space d grows, the loading range between initiation stress and maximum stress increase.