A loading device for crack expansion of concrete members under reciprocating load

Abstract

The invention provides a concrete member cracking and extending loading device under the action of reciprocating loads. The device comprises an MTS testing machine acting head, an axial force sensor, an epsilon-shaped loading frame, bearings, square bearing frames and a force transmission steel shaft. The reciprocating loads in the testing process sequentially act on a concrete test piece from the middle and the two sides of the epsilon-shaped loading frame through the bearings, the square bearing frames and the force transmission steel shaft. The bearings are arranged through the symmetric square bearing frames, the influence of rotation between the force transmission steel shaft and the concrete test piece is overcome, and the influence of friction in the load transmission process is reduced. Real-time load curves during opening and closing of a crack can be obtained through a load curve recorded by the axial force sensor via computational formula transformation. The device can provide reliable guarantee for experiments of the cracking, extending and closing processes of the concrete test piece, the opening and closing processes of the crack are completely achieved, and the device can be used for problem research on observation of the cracking and extending processes of the concrete structure under the dynamic loads.

Description

technical field [0001] The invention belongs to the technical field of tensile and compression experiments of concrete members, and in particular relates to a compact tension-compression loading device under the action of dynamic load, which provides a device for simulating the crack opening and closing process of concrete members under the action of reciprocating load Dynamic loading device. Background technique [0002] In recent years, a large number of water conservancy projects have been built or are under construction in my country. Most of these water conservancy projects are located in the northwest and southwest regions with frequent seismic activities. They are used to control and regulate the flow of rivers. To adjust the flood peak and prevent the occurrence of flood disasters. As one of the most widely used engineering materials in these hydraulic structures, concrete usually needs to be batched, mixed, cured and shaped, and any carelessness in each link will af...

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Problems solved by technology

However, most of the compact tensile tests are used for components under static loads, and cannot be measured under dynamic loads; some patents suggest using springs or magnets to provide tension to achieve the application of dynamic loads, but due to the spring or magnet itself Due to the limitation of properties, the tension provided is limited, and it is difficult to fully realize the closing process of cracks. There is a certain difference between the dynamic load in the test and the actual stress state

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