与医用CT配套的便携式材料试验机的研制及其在混凝土损伤研究中的应用

Manufacture of Portable Material Test Device Forming a Complete Set with Medical X-Ray CT and its Application in Concrete Damage Study

混凝土内部细观裂纹的演化规律研究可以解释其动态特性和损伤破坏机理。X射线CT技术是无损探测混凝土内部细观裂纹萌生、扩展、贯通的有效手段。与医用CT配套的便携式材料试验机是进行混凝土CT试验的关键加载设备。本文概要介绍研制便携式材料试验机的研制过程。论述实现动态加载的几个关键技术问题,包括加载设备的便携式要求、加载波形显示、加载控制、试件安装和粘结技术等。经过试验,表明所研制的加载设备达到了使用要求。混凝土动力压缩条件下突发性裂纹的出现是其动态强度提高的原因之一。

Dynamic characteristics and damage mechanism of concrete material can be explained by its internal meso-crack evolution process. X-ray computerized tomography （CT） technique is an effective tool to detect the initiation, propagation and continuous accumulation of internal meso-cracks, that leads finally to macro cracks. Portable material test device forming a complete set with medical X-ray CT scanner is a key loading equipment in concrete CT test. This paper generally introduces the manufacturing process of the portable material test device. Some key techniques to implement dynamic loading are..discussed including how to meet the portable demand, how to display loading wave and loading controlling, specimen installing and cohering techniques. According to test results, the portable test device has achieved the design demand. Cracks break out in concrete under a dynamic compression condition is one of the reasons causing concrete dynamic strength＇s increase.