Multi-axial fatigue fracture test equipment for bridge expansion joint material and implementation method of multi-axial fatigue fracture test equipment

Abstract

The invention belongs to the technical field of bridge engineering, and relates to multi-axial fatigue fracture test equipment for a bridge expansion joint material and an implementation method of the multi-axial fatigue fracture test equipment. The fatigue fracture test equipment comprises an external frame, a transmission device, a concrete member, the expansion joint material, a temperature sensor and a normal loading device, wherein the concrete member comprises a fixed concrete member and a movable concrete member between which a slit used for accommodating the expansion joint material is reserved; the movable concrete member is used for realizing horizontal movement; the normal loading device comprises a solid rubber wheel which is used for realizing normal loading; the acting force of the wheel to the expansion joint material is simulated through a cylinder and a motor. Compared with the prior art, the fatigue fracture test equipment can sufficiently simulate the actual working condition of the expansion joint material under the combined action of bridge expansion change and vehicle load, so that the fatigue performance of the material under different expansion quantity, vehicle load and expansion frequency can be studied.

Description

technical field [0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a bridge expansion joint material multiaxial fatigue failure test equipment and an implementation method thereof. Background technique [0002] In order to meet the expansion and deformation of the bridge, bridge expansion joints are added in the design, so that the bridge can expand and contract freely at this place, and avoid internal stress. The material at the expansion joint is different from the main structural material of the bridge. In addition to bearing the load of the vehicle, it is also frequently stretched and compressed. In addition, it is exposed to the air for a long time. The use environment is harsh, easy to damage, and the maintenance cost is high. At present, the direct tension and compression fatigue test is widely used in China to test the fatigue performance of expansion joint materials. It does not consider the effect of vehicle load...

AI Technical Summary

Problems solved by technology

When the mixed material is subjected to multi-axial loading, it is more difficult to judge the fatigue trend from which factors. At present, there is no equipment that can test the fatigue life of mixed materials under multi-axial loading at different frequencies. Attached image 3 Shown are the fatigue life and measured life curves of metal components estimated by the maximum principal strain method under multiaxial loads of the same frequency in tension and torsion. It can be seen from the figure that the fatigue life obtained by the prediction method is not very close to the actual fatigue life curve Good coincidence is of great significance to the actual determination of material fatigue life

When the environment of the material changes or the test specimen is not a standard specimen, there may be a greater deviation between the life value obtained by the estimation method and the actual value, which cannot guide the design and production well, and it is more necessary to approach the actual value. Determination of fatigue life under working conditions

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