Displacement extension clamping device for measuring axial tensile deformation of steel cable at high temperature and using method of displacement extension clamping device

Abstract

The invention discloses a displacement extension clamping device for measuring axial tensile deformation of a steel cable at high temperature and a using method of the displacement extension clamping device. The displacement extension clamping device for measuring the axial tensile deformation of the steel cable at high temperature comprises an upper clamp, a lower clamp and a high-temperature extensometer, wherein each of the upper clamp and the lower clamp comprises a U-shaped tube clamp, a V-shaped claw, bolts, a base and high-temperature nuts; U-shaped tube clamps sleeve a sample; two ends of each U-shaped tube clamp are respectively connected with the two corresponding bolts; each V-shaped claw is further arranged on the corresponding base; the U-shaped tube clamps and the V-shaped claws oppositely fasten to clamp the sample; the high-temperature nuts are tightened through the bolts, so that the sample, the U-shaped tube clamps and the V-shaped claws cannot slide relatively; the high-temperature extensometer is provided with two extension rods; a blade contact is arranged at the top end of each extension rod; the extension rods are adjusted so that the two blade contacts can be respectively inlaid in wedge-shaped grooves formed in the surfaces of the top ends of the two U-shaped tube clamps; high-temperature deformation in a gauge length section of the sample is transmitted to the extension rods; and test data are recorded by the high-temperature extensometer.

Description

technical field [0001] The invention relates to the technical field of building structural material testing, in particular to a displacement extension clamping device for measuring the axial tensile deformation of a steel cable at high temperature and a use method thereof. Background technique [0002] Prestressed tensioned steel structures have high structural efficiency. At present, the research on the bearing capacity of such structures under fire is mainly based on numerical simulation methods, and the accuracy of high-temperature mechanical properties of materials is an important link that affects the reliability of numerical simulation methods. Steel cables are the core components of prestressed tensioned steel structures, and their high-temperature mechanical properties are mainly obtained through experimental tests. At present, due to the influence of temperature, test equipment, component specifications and other factors, the high-temperature mechanical performance...

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Problems solved by technology

[0003] At present, in the high-temperature material properties tests carried out at home and abroad, the deformation measurement devices of the specimens at high temperatures are mostly side-inserted high-temperature extensometers, which are used together with the matching high-temperature furnace. For steel cables (such as steel strands, Steel wire bundles, steel wire ropes) and other cylindrical geometries cannot be processed into "machined samples" in accordance with the provisions of "Metallic Materials High Temperature Tensile Test Method" GB / T4338-2006. There are two main problems in the use of this extensometer: 1. When using a high-temperature extensometer to measure the deformation of steel strands (made of multiple steel wires twisted in a spiral shape) and steel wire bundles (made of multiple steel wires arranged in parallel or slightly twisted), the measured The deformation is actually the elongation of a single steel wire, not the elongation of the entire steel cable; 2. The steel cable is mostly composed of 5mm or 7mm steel wires, and the contact range with the end of the extensometer is similar to point contact. During the process, relative slippage easily occurs between the extensometer end contact and the sample surface, resulting in large errors in the axial deformation test data of the sample, and it is impossible to establish an accurate high-temperature mechanical performance index system

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