循环加卸载条件下沙粒的力学试验及模型研究

发布时间：2018-02-09 18:55

本文关键词： 循环加卸载应力-应变曲线散粒体力学模型临时支护　出处：《安徽理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：在生活中我们经常见到临时支护设备,在桥梁、建筑、隧道和煤矿上都有着广泛的应用,生活中最常见的就是沙箱式临时支座,它利用封闭容器内的干燥细沙,在容器底部或侧面打开开口时易流出从而减少容器内的细沙体积的原理设计的。不同的盖梁可以用沙箱内沙子的多少来调整高度。在其他工序完成之后,需要将临时支座的大梁放置到永久支座上时只需将沙箱一侧的螺旋开关拧开,轻轻敲击,沙子就会流出,大梁就会随沙箱内沙子的减少在自重作用下落到永久支座上,即方便、又简单。但是依旧有着其缺点和不足：沙粒的选择依据、厚度的大小及应力不稳定的时候沙子所能承受的最大应力等问题。解决这些问题具有重要理论参考价值和工程借鉴意义。以沙子作为充填材料并对其进行循环加卸载实验,采用实验中常用的控制变量法,研究的3个变量分别是：粒径、厚度、加载方式,研究其力学性质,抗压强度,破坏程度,寻找出所承受的力、侧限和研究变量的关系,实验使用RMT-150B试验机,做单轴压缩,采用循环加卸载实验；研究沙子在循环加载的条件下的力学性质,实验中再次使用到其他的参数,例如表观密度,堆积密度,加载速率这些参数始终贯穿始终；采用不同粒径厚度的沙子,进行循环加卸载实验,研究沙粒的循环加卸载最大多能承受得住应力强度,及沙子的应力应变关系,统计出不同粒径的强度规律,及绘制出应力应变曲线及弹性模量,泊松比等一系列的参数；希望可以进一步的完善；临时支护设备提供参考和依据。并建立模型： (1)等量循环加卸载应力应变曲线方程。 (2)相同粒径不同厚度条件下循环次数和轴向变形之间的模型。 (3)相同厚度不同粒径条件下循环次数和轴向变形之间的模型。
[Abstract]:We often see temporary support equipment in our lives. It is widely used in bridges, buildings, tunnels and coal mines. The most common in life is the temporary support of sand box, which uses dry sand in closed containers. Designed to reduce the volume of fine sand in the container by opening the opening at the bottom or side of the container. Different cover beams can be adjusted with the amount of sand in the sand box. After other processes are completed, When it is necessary to place the beam of the temporary support on the permanent support, just unscrew the spiral switch on one side of the sand box, tap lightly, the sand will flow out, and the beam will fall to the permanent support with the decrease of sand in the sand box, that is, it is convenient. And simple. But still has its shortcomings and shortcomings: the basis for the selection of sand, The magnitude of thickness and the maximum stress that the sand can bear when the stress is unstable has important theoretical reference value and engineering reference value to solve these problems. Sand is used as filling material and cyclic loading and unloading experiments are carried out. Three variables are studied: particle size, thickness, loading mode, mechanical properties, compressive strength, and damage degree, using the control variable method commonly used in the experiment. To find out the relationship between the force, the side limit and the research variables, the experiment uses RMT-150B testing machine, makes uniaxial compression, uses cyclic loading and unloading experiments, studies the mechanical properties of sand under cyclic loading. Other parameters, such as apparent density, packing density, loading rate, are used again throughout the experiment, and cyclic loading and unloading experiments are carried out using sand with different particle sizes. A series of parameters, such as stress-strain curve, elastic modulus and Poisson's ratio, are obtained by studying the maximum load-unloading capacity of sand under cyclic loading and unloading, and the relationship between stress and strain, and the relationship between stress and strain, and the relationship between stress and strain, as well as the relationship between stress and strain, as well as the relationship between stress and strain. Hope can be further improved; temporary support equipment to provide reference and basis. And establish the model:. 1) the stress-strain curve equation of constant cyclic loading and unloading. (2) the model of cycle number and axial deformation under the same particle size and different thickness. (3) the model of cycle number and axial deformation under the same thickness and different particle size.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD350

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