3D打印技术在岩石力学试样制备方面的应用探讨

发布时间：2018-04-30 06:31

本文选题：3D打印 + 试样制备　；参考：《南京大学》2015年硕士论文

【摘要】：以往岩石力学室内试验样品主要通过野外取样(原岩样品)或模具浇筑(类岩石材料样品)两种方法获得,但由上述两种方法取得的样品均存在一些问题,如天然岩石内部难以被观测到、不存在完全相同的两块岩石、浇筑样品时产生的气泡沉淀等,同时岩石力学试验又大多是破坏性试验,这使得需要较多样品完成的试验(如不同围压下的岩石特性、岩石动静态试验等)会因为样品的差异而造成数据离散性较大(有时甚至会对研究者产生误导),进而对岩石力学研究起到一定的障碍作用。因此,本文对一种全新的样品制备方法—3D打印技术进行了初步探讨,希望为岩石力学研究中的样品制备提供一种新的思路。本文针对以石膏粉末和光敏树脂为原材料的3D打印样品及砂岩试样,进行了 CT扫描、物理力学和渗透指标的测试及分析,获得主要结论如下:(1)石膏粉末样品打印时,虽然每层石膏粉末厚度可控,但用于固结的胶水量不可控,最终导致各石膏粉末样品间差异较大,其对应的物理力学性质指标也相去甚远,因而无法用于制作重复性较好的类岩石试样。(2)以半透明的光敏树脂为原材料进行样品制作时,通过后续加工处理能去除打印过程中填充在有效孔隙中的蜡质材料,因此,使用光敏树脂3D打印技术可打印含有有效孔隙的样品。(3)通过CT扫描与图像分析,确认各光敏树脂样品间的几何特征较为一致,而样品与原模型之间存在一定偏差,主要体现在封闭孔隙被蜡质材料填充及错台效应导致的小孔隙变形或堵塞。(4)通过对光敏树脂样品和砂岩物理力学和渗透指标进行测试,发现光敏树脂样品的各项指标差异性远小于砂岩样品,验证了光敏树脂样品可重复性较好。同时单轴压缩试验中光敏树脂样品破坏时的压缩量超过25%,塑性较高,因此该材料不能很好的模拟类岩石材料的抗压特性,但渗透试验结果表明光敏树脂样品可较好的应用于具有较大孔隙或裂隙样品的渗透测试。
[Abstract]:In the past, the samples of laboratory test of rock mechanics were mainly obtained by two methods: field sampling (original rock samples) or mold casting (rock like materials samples). However, there are some problems in the samples obtained from the above two methods. For example, it is difficult to observe the interior of natural rock, there are not two identical rocks, the bubble precipitates produced by pouring samples, and most of the rock mechanics tests are destructive tests at the same time. This results in tests that require a larger number of samples (such as rock characteristics under different confining pressures), Because of the difference of the samples, the data dispersion (sometimes even misled to the researchers) will be caused by the rock dynamic and static test, which will play a certain obstacle to the study of rock mechanics. Therefore, a new method of sample preparation-3D printing is discussed in this paper, in order to provide a new idea for the study of rock mechanics. In this paper, 3D printed samples and sandstone samples with gypsum powder and Guang Min resin as raw materials are tested and analyzed by CT scanning, physical mechanics and permeability. The main conclusions are as follows: 1) when the gypsum powder sample is printed, Although the thickness of each layer of gypsum powder is controllable, the amount of glue used for consolidation is not controllable, resulting in great differences between the samples of gypsum powder and the corresponding physical and mechanical properties. Therefore, it can not be used to make more reproducible rock-like sample. 2) when the translucent Guang Min resin is used as the raw material for sample making, the waxy material filled in the effective pore during the printing process can be removed by subsequent processing, so, By using Guang Min resin 3D printing technique, we can print samples with effective pores. (3) by CT scanning and image analysis, we can confirm that the geometric characteristics of the samples of Guang Min resin are consistent, but there is a certain deviation between the samples and the original model. Mainly reflected in the small pore deformation or blockage caused by the filling of sealed pores with waxy materials and staggered platform effect.) the physical, mechanical and permeability indexes of Guang Min resin samples and sandstone were tested. It is found that the difference of indexes of Guang Min resin sample is much less than that of sandstone sample, which verifies the reproducibility of Guang Min resin sample. At the same time, in uniaxial compression test, the compression amount of Guang Min resin sample is more than 25% and the plasticity is high, so the material can not simulate the compressive properties of rock-like material very well. However, the results of permeation test show that Guang Min resin sample can be applied to the permeability test of samples with large porosity or fissure.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45

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