准静态一维应变实验装置的设计与验证研究

准一维应变状态测试技术对混凝土等脆性材料的力学性能研究具有重要意义,而目前准一维应变实验装置设计单一、互换性较差,所以无法实现普及。针对上述情况,本文在套管围压装置的基础上进行叠加式设计与组合式分离设计,旨在建立一套结构简单、适用性广的准静态被动围压装置。基于数值模拟方法,本文对混凝土试样在一维应变状态与套管围压作用下的力学特性进行研究,从而分析混凝土试样在套管装置下能达到一维应变状态的程度;同时,对叠加式套管与整体式套管的性能进行比较,发现叠加式套管理论上能在准一维应变实验中很好地代替整体式套管。组合式分离设计的有效性最终通过相关实验得到验证。

On the Design and Validation of Quasi-Static One-Dimensional Strain Experimental Device

Quasi one-dimensional strain testing technology is very significant for mechanical property study of brittle materials such as concrete. At present, the designs of quasi one-dimensional strain experimental device are single and with poor interchangeability, so it is impossible to achieve universal. In order to solve this problem, stacked design and combined separation design based on the casing confining pressure device are proposed in this paper, which aims to establish a set of quasi-static passive confining pressure device with simple structure, wide applicability. Based on numerical simulation, mechanical behavior of concrete specimens in one-dimensional strain state and subjected to confining pressure action was studied. Thus, the degree of one-dimensional strain state achieved by concrete specimen in sleeve device was analyzed. Meanwhile, the performance comparison between stacked and integrated confining tube device was carried out. It was found that the stacked confining tube can theoretically replace the integrated confining tube in the quasi-static one-dimensional strain tests. Eventually, the practicability of combined separation design was proved by correlative experiments.