茂木式真三轴试验机的端部摩擦效应

发布时间：2018-04-20 09:25

本文选题：岩石力学 + 真三轴试验机　；参考：《岩石力学与工程学报》2017年11期

【摘要】：茂木式真三轴试验中需要在加载装置和试件之间至少设置两对刚性接触的垫块,由于加载过程中端部摩擦限制了试件的自由变形,因而提高了试样的测试强度。为定量评估端部摩擦效应,采用同一批红砂岩试样开展不同端部摩擦因数和中间主应力条件下的双向压缩试验,试验结果表明,不同端部摩擦因数条件下的试件强度测试值存在显著差异,相同中间主应力条件下摩擦因数从0.12提高到0.28时,最大主应力极限值提高5.5%~43%。基于试验数据分析采用不同破坏准则时摩擦效应的合理性,结果表明应变能准则对双向受压工况适用性最好。基于试验数据和应变能准则,建立摩擦效应的定量表达式,绘制考虑摩擦效应的中间主应力效应曲线,分析摩擦效应对1 2?-?曲线形状的影响,分析结果与试验数据吻合良好。通过试验揭示摩擦效应的重要影响,建立定量分析模型,对于评价真三轴试验数据的可靠性具有重要参考意义。
[Abstract]:In the true triaxial test of Maomu type, at least two pairs of rigid contact pads should be set between the loading device and the specimen. Because the friction at the end of the specimen limits the free deformation of the specimen during the loading process, the test strength of the specimen is improved. In order to quantitatively evaluate the end friction effect, a series of red sandstone samples were used to carry out bi-directional compression tests under different end friction coefficients and intermediate principal stresses. The experimental results show that, There are significant differences in the strength test values of the specimens under different end friction coefficient conditions. When the friction coefficient increases from 0.12 to 0.28 under the same intermediate principal stress condition, the maximum principal stress limit value increases by 5.5% and 43%. Based on the experimental data, the reasonableness of friction effect under different failure criteria is analyzed. The results show that the strain energy criterion is the most suitable for biaxial compression. Based on the experimental data and strain energy criterion, the quantitative expression of friction effect is established, and the intermediate principal stress effect curve considering friction effect is drawn. The effect of curve shape is in good agreement with the experimental data. The important effect of friction effect is revealed through experiments and the quantitative analysis model is established. It is of great significance to evaluate the reliability of true triaxial test data.
【作者单位】：陆军工程大学爆炸冲击防灾减灾国家重点实验室;
【基金】：长江科学院开放研究基金资助项目(CKWV2017506/KY) 国家自然科学基金资助项目(51527810) 江苏省自然科学基金资助项目(BK20171400)~~
【分类号】：TU45

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