Device for using stable isothermal layer to testing structure dynamic properties

Abstract

The invention discloses a device for using a stable isothermal layer to testing structure dynamic properties. The isothermal layer exists in a temperature box. After the starting of a heat source, the temperature in the box forms a natural gradient along the vertical direction due to a gas heat-expansion and cold-contraction characteristic and the natural adjustment of gravity. The temperature at the same horizontal height is identical and varies little with time. According to the invention, a temperature field of the stable isothermal layer is used, the uniform temperature of a test-piece is ensured and the dynamic property test of the test-piece is completed. According to the invention, the isothermal layer is formed through the natural convection of gas, the temperature control difficulty is lowered, the reliability is high, the power dissipation is low, the space is saved; the rapid switching of a temperature point can be realized through moving the test-piece into different isothermal layers; the device is simple, and the disassembly and assembly are convenient; in addition, micro-adjustment is performed on the temperature gradient by means of thermal insulation, heat reflection and heat dissipation processing of the box, and the temperature control is flexible.

Description

technical field [0001] The invention relates to the technical field of testing the dynamic characteristics of mechanical structures, in particular to a device for testing the dynamic characteristics of structures using a stable isothermal layer. Background technique [0002] The dynamic characteristics of mechanical structures include natural frequency, mode shape, damping, etc. Dynamic characteristic tests are generally carried out under normal temperature conditions. However, for structures operating under extreme conditions, evaluation of their dynamic characteristics at different temperatures needs to be completed. For example, under strong sunlight conditions, the body temperature of a high-speed train can reach above 50°C. If only the test results at room temperature of 20°C are used, it is obviously unable to meet the design requirements. An important evaluation index of the train body is the loss factor, which is often tested with a beam specimen that is consisten...

AI Technical Summary

Problems solved by technology

[0004] (1) The temperature in the space inside the box fluctuates greatly, and the fluctuation law is complicated, which is difficult to grasp;

[0005] (2) The hot air generated by the fan is noisy and consumes a lot of energy;

[0006] (3) Only one temperature point test can be completed at a time;

[0007] (4) The equipment is heavy and occupies a large area

[0008] This affects the accuracy and stability of the high-temperature dynamic characteristic test of the structure, prolongs the test cycle, and causes waste of energy and space at the same time

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