ECC axial tension test deformation monitoring system and method

Abstract

The invention discloses an ECC axial tension test deformation monitoring system and method. The system mainly comprises a tension clamp, a template for fixing the tension clamp in the test-piece pasting process, a displacement sensor fixing support, a springback displacement sensor and a collecting box. The tension clamp comprises two steel plates and a chuck. The steel plates and the chuck are clamped by tooth grooves and anchored by two bolts, and therefore it is ensured that the test-piece is axially tensioned in the direct tension process. The template for fixing the tension clamp in the test-piece pasting process comprises two clamping plates and two baffles, the clamping plates and the baffles are connected through bolts, the width of the baffles is consistent to the width of the test-piece, and it is ensured that the test-piece does not deflect in the pasting process. The displacement sensor fixing support comprises two top beams and bottom beams. The beams are fixed to the test-piece through rapid-hardening glue and anchoring of bolts, and meanwhile, the two ends of the top beams and the two ends of the bottom beams are installed on sliding blocks in a screwed mode, wherein the sliding blocks move on the beams left and right. The fixing support is suitable for testing test-pieces of different sizes.

Description

technical field [0001] The invention relates to an ultra-high toughness cement-based composite material (Engineered CementitiousComposite, ECC) axial tension test and displacement deformation monitoring system and method. Background technique [0002] At present, for the use of ultra-high toughness cement-based composites, they will show obvious strain hardening characteristics under both bending load and direct tensile load. In order to verify the strain hardening characteristics of ECC materials, the direct tensile test is the best way to test the strain hardening properties of ECC materials. [0003] Today, the research on the mechanical properties of ECC composites mainly focuses on the flexural and four-point bending tests. Although there are also a lot of experimental studies on the tensile strength of ECC composite materials, such as direct tensile tests using dumbbell-shaped specimens, and direct tensile tests using rectangular thin plates, the fixing brackets of th...

AI Technical Summary

Problems solved by technology

Although there are also a lot of experimental studies on the tensile strength of ECC composite materials, such as direct tensile tests using dumbbell-shaped specimens, and direct tensile tests using rectangular thin plates, the fixing brackets of the LVDT displacement sensors are fixed by bolts. This requires the operator to have sufficient experience. If the bolts are not tightened tightly enough, the fixing bracket will easily slip off when the specimen is stretched. If the bolts are tightened too tightly, it will easily cause a weak section at the bolt position of the specimen, causing premature fracture and damage. , there are also fixed brackets in other ways, but they can only monitor the displacement of specimens of specified size

At the same time, the existing tensile fixtures can only visually observe the axial tension, and the eccentricity will inevitably be caused by the different test operation techniques and personnel.

Images