不同胶结物粒间胶结三维仿微观力学试验

发布时间：2018-02-06 03:16

  本文关键词： 胶结铝球 微观模型试验 环氧树脂 高铝水泥　出处：《同济大学学报(自然科学版)》2017年11期 　论文类型：期刊论文

【摘要】：离散单元法被广泛应用于颗粒材料的力学特性研究,建立合理的胶结微观接触理论对实现胶结型岩土材料宏观、微观力学特性的数值分析显得尤为重要.首先通过室内三维接触试验方法制备由环氧树脂和高铝水泥胶结的铝球试样,并使用辅助加载装置进行拉伸、压缩、剪切、弯曲及扭转5种加载方式下的接触力学特性测试,为建立三维微观接触模型奠定试验基础.结果表明,胶结铝球颗粒的接触力学响应及强度包线与胶结物类型有关.在峰值前,胶结铝球的力-位移与力矩-转角变化关系曲线表现为线弹性;在峰值后,表现为环氧树脂偏塑性、高铝水泥偏脆性;法向作用力对胶结接触力学特性有重要影响,不同胶结铝球的抗剪、抗弯、抗扭能力随着法向作用力的增大呈现先增大后减小趋势,存在临界法向应力比;在不同荷载空间下,不同胶结铝球颗粒的归一化峰值强度包线(剪切强度、弯矩、扭矩-法向荷载)近似呈抛物线型.
[Abstract]:The discrete element method is widely used in the study of mechanical properties of granular materials, and the establishment of a reasonable cemented micro-contact theory for the realization of cemented rock and soil materials macro. Numerical analysis of microscopic mechanical properties is particularly important. Firstly, aluminum ball specimens cemented by epoxy resin and high aluminum cement are prepared by three dimensional contact test method in laboratory, and tensile and compression are carried out with auxiliary loading device. The test results of contact mechanical properties under shear, bending and torsion loading provide the experimental basis for the establishment of three-dimensional micro-contact model. The contact mechanical response and the strength envelope of the cemented aluminum ball particles are related to the type of the cemented aluminum ball. Before the peak value, the curve of the relationship between the force, displacement, torque and rotation angle of the cemented aluminum ball is linear elasticity. After the peak value, the epoxy resin is partial plastic, and the high aluminum cement is partial brittleness. The normal force has an important effect on the contact mechanical properties of the cement. The shear, bending and torsion resistance of different bonded aluminum balls increase first and then decrease with the increase of the normal force, and there is a critical normal stress ratio. Under different loading space, the normalized peak strength envelope (shear strength, bending moment, torque-normal load) of different cemented aluminum ball particles is approximately parabola.
【作者单位】： 同济大学土木工程防灾国家重点实验室;同济大学岩土及地下工程教育部重点实验室;同济大学土木工程学院;天津大学土木工程系;
【基金】：国家“九七三”重点基础研究发展计划(2014CB046901) 国家自然科学基金重点项目(51639008) 同济大学土木工程防灾国家重点实验室项目(SLDRCE14-A-04)
【分类号】：TU43
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本文编号：1493443