新型土工动三轴试验仪的研制

发布时间：2018-02-21 19:37

本文关键词： 动三轴试验仪全表面数字图像测量系统液压伺服加载系统双向激振控制小载荷精确测量　出处：《大连理工大学》2013年硕士论文　论文类型：学位论文

【摘要】：土工建筑物及其地基除承受静载荷作用之外,有时也会受到动载荷的作用,如地震、车辆、机器及爆炸引起的震动载荷。研究与评估动载荷作用下的土工建筑物及其地基的稳定性和变形,需要对有关土体的动态特性进行分析掌握,如土体的变形特性和强度特性。室内进行的土体动态特性研究主要方法是动三轴试验,土工动三轴试验仪是专门用于动三轴试验的仪器,因此土工动三轴试验仪的研发工作对土的动态特性研究极为关键。虽然我国土工动三轴试验仪的研制已有五十余年,但目前仍与国外知名公司的产品存在较大差距,研发具有自主知识产权的土工动三轴试验仪已成为我国土工试验仪器研发的重要工作。针对国内外动三轴试验仪由双向激振耦合引起的动载荷加载精度不高,以及接触式测量易引扰动试样等问题,研发更高精度、更易精确测量试样变形的动三轴试验仪具有重要作用与意义。本文作者研制的新型土工动三轴试验仪借鉴了国内外现有的动三轴试验仪,引入具有自主知识产权的全表面数字图像测量技术及双激振控制技术等,将新型土工动三轴试验仪的性能提高至国内外先进水平。液压伺服加载系统中蓄能器组和恒压变量泵的选用,保证了动态加载时压力波动小以及静态加载时油源系统节能。依托于全表面数字图像测量技术的应用,实现了非接触式测量,通过试样表面标定点的位置改变和后台软件的计算处理,得到试样的体应变；摄像机不间断的拍摄记录试样的变化过程,对土体的动态特性研究具有重要意义。新型土工动三轴试验仪也具有双向激振精确控制、小载荷精确测量、应用辅助提升装置等功能特点。结合土工动三轴试验仪的原理和仪器的功能要求,本文作者完成了新型土工动三轴试验仪压力室、伺服加载系统、试验操作平台等全部机械设计,引入全表面数字图像测量系统,安装并调试试验仪器并进行试验,以及试验后对数据的分析等工作。
[Abstract]:In addition to static loads, geotechnical structures and their foundations are sometimes subjected to dynamic loads, such as earthquakes, vehicles, Vibration loads caused by machines and explosions. To study and evaluate the stability and deformation of geotechnical structures and their foundations under dynamic loads, it is necessary to analyze and master the dynamic characteristics of the soils concerned. For example, the deformation and strength characteristics of soil mass. The main method of dynamic characteristics of soil is dynamic triaxial test, and the geotechnical triaxial test instrument is specially used for dynamic triaxial test. Therefore, the research and development of geotechnical triaxial test instrument is very important to the study of soil dynamic characteristics. Although the development of geo-dynamic triaxial test instrument in China has been more than 50 years, there is still a big gap with the products of famous foreign companies. The research and development of geotechnical triaxial test instrument with independent intellectual property rights has become an important work in the research and development of geotechnical test instruments in China. Aiming at the problem that the dynamic load loading precision of the dynamic triaxial test instrument at home and abroad caused by the bidirectional excitation coupling is not high, and the contact measurement method is easy to lead to the disturbance sample and so on, a higher precision is developed. The dynamic triaxial test instrument, which is more convenient and accurate for measuring specimen deformation, is of great importance and significance. A new type of dynamic triaxial test instrument developed by the author of this paper has drawn lessons from the existing dynamic triaxial test instrument at home and abroad. Introducing full-surface digital image measurement technology with independent intellectual property rights and dual-excitation control technology, etc. The performance of the new type geodynamic triaxial test instrument is improved to the advanced level at home and abroad. The selection of accumulator group and constant pressure variable pump in hydraulic servo loading system, It ensures the low pressure fluctuation in dynamic loading and energy saving of oil source system under static loading. Based on the application of full-surface digital image measurement technology, non-contact measurement is realized. The volume strain of the sample is obtained by changing the position of the surface of the specimen and the calculation of the backstage software, and the process of the change of the sample is recorded by the camera without interruption. It is of great significance to study the dynamic characteristics of soil. The new type of geo-dynamic triaxial test instrument also has the functions of accurate control of bidirectional excitation, accurate measurement of small load and application of auxiliary lifting device. Combined with the principle of the geodynamic triaxial test instrument and the functional requirements of the instrument, the author has completed all the mechanical design of the new type geodynamic triaxial test instrument, such as pressure chamber, servo loading system, test operating platform, etc. The full surface digital image measurement system is introduced, the test instrument is installed, debugged and tested, and the data analysis after the test is carried out.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU415

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