Engineering structure mechanical strain testing method and device capable of eliminating temperature influence

Abstract

The invention discloses an engineering structure mechanical strain testing method and device capable of eliminating a temperature influence. It is discovered that an actual strain of an engineering structure comprises an influence of external constraints or materials on the engineering structure in addition to a mechanical strain of the structure, so that the expansion or contraction deformation is unlikely to freely occur, an effective temperature strain of the engineering structure corresponding to an engineering structure stress is caused, and first strains of the engineering structure under the condition that an external mechanical load effect does not exist at different environment temperatures are obtained through a temperature compensation method to establish relations between the environment temperatures and first dependent variables; then the actual strain of the structure under the condition that the mechanical load effect exists at a working environment temperature is measured; and according to a single-variable principle, the first strain of the engineering structure under the condition that the external mechanical load effect does not exist at the corresponding temperature is subtracted according to the actual strain of the engineering structure at the working environment temperature to counteract the effective temperature strain of the engineering structure, and the mechanical load strain of the engineering structure is obtained, so that the influence of the external mechanical load effect on the structure is accurately reflected, and the performance evaluation of the engineering structure is facilitated.

Description

technical field [0001] The invention belongs to the field of engineering structure mechanical strain testing, and in particular relates to a method and device for engineering structural mechanical strain testing which eliminates the influence of temperature. Background technique [0002] Structural resistance strain test technology is to paste the resistance strain gauge on the surface of the test structure to ensure the joint deformation of the structure and the strain gauge. By measuring the change of the resistance of the resistance strain gauge, the strain of the structure is calculated, and then the stress at the measuring point of the structure is obtained. . However, the resistance value of the sensitive grid of the resistance strain gauge changes with the change of temperature, and its strain measurement data cannot reflect the actual strain of the engineering structure. Generally, the method of temperature strain compensation is used to solve the problem, that is, t...

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Problems solved by technology

This method needs to apply standard loads step by step to the load sensor at various ambient temperatures, which is only suitable for small structures with small loads. For large engineering structures with heavy loads, such as measuring the strain of bridge structures under vehicle loads , it is not feasible to obtain the curve of the load value output by the load sensor as a function of different temperatures. Therefore, it is necessary to find a mechanical strain test method widely applicable to engineering structures

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