High-precision measuring device and measuring method for volume change of irregular solid thermal expansion and contraction

Abstract

The invention discloses an irregular solid heat expansion and cold contraction volume change high-precision measuring device and method. The measuring device comprises an iron stand, a glass cup, a rubber plug, a glass round straight pipe, a liquid, a foamed thin sheet and a dial indicator, wherein the iron stand comprises an iron stand vertical rod, an iron stand beam and an iron stand base; the glass cup is arranged on the iron stand base; the diameter of the rubber plug is matched with the inner diameter of the glass cup; the glass round straight pipe transversely runs through the center of the rubber plug, and the bottom end is level with the lower end face of the rubber plug; the foamed thin sheet is of a round structure, and the diameter of the foamed thin sheet is matched with the inner diameter of the glass round straight pipe; the foamed thin sheet floats on the level of the liquid inside the glass round straight pipe and is capable of freely sliding up and down inside the pipe along with the lifting of the level of the liquid; and the dial indicator is fixedly on the beam of the iron stand. The method disclosed by the invention can balance the change of liquid level inside the glass round straight pipe through the deflection of a pointer of the dial indicator; the detection precision is far higher than direct reading of the level of the liquid inside the glass round straight pipe; and the influence of temperature change on the size of the glass cup and the volume of the liquid can be effectively eliminated in a calculating process.

Description

technical field [0001] The invention relates to the field of geotechnical engineering, and belongs to a physical experiment method, which is suitable for measuring the volume change of irregular solids that expand with heat and contract with cold when the temperature changes. Background technique [0002] Expansion with heat and contraction with cold is one of the essential properties of all things in nature. Macroscopically, it is manifested in the increase of temperature and volume increase, and the decrease of temperature and volume decrease. For the field of geotechnical engineering, the current method of measuring the volume change of solid materials thermal expansion and contraction is to prefabricate it into a cuboid or cylindrical sample, first use a vernier caliper to measure the linear strain of a certain end face of the sample, and then according to the geometry The feature calculates its volume change. This method has two major disadvantages; first, it has speci...

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Problems solved by technology

This method has two major disadvantages; first, it has specific requirements for the geometric shape of the sample, and it cannot measure the volume change of irregular bodies when the temperature changes; second, most rock and soil bodies such as concrete and rock belong to the anisotropic For heterogeneous materials, this method of calculating the overall volume change from a single end surface line strain does not match the actual situation, and there are large errors

For the physical experiment method, the volume of the spilled liquid is usually directly measured by a container with a scale and replaced by the volume of the sample. Although this method can first measure the volume of the irregular body at different temperatures, and then calculate the volume change However, since the sensitivity of solid materials to temperature changes is generally low, when the sample volume or temperature changes are small, the measurement results are not obvious, and the accuracy cannot meet the requirements

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