Geosynthetic material tensile sample global strain field measuring device and method

Abstract

The invention discloses a geosynthetic material tensile sample global strain field measuring device and method. The device comprises a high-definition camera, a to-be-tested sample, a computer and a data acquisition and analysis system. The high-definition camera is connected with the computer and the data acquisition and analysis system through data lines, a marking grid is arranged on the surface of the to-be-tested sample, and a lens of the high-definition camera is over against the marking grid on the surface of the to-be-tested sample. The measurement efficiency is remarkably improved, the adaptability is high, and the measurement method is simple and efficient.

Description

technical field [0001] The invention relates to a strain field measuring device and method, in particular to a global strain field measuring device and method for a geosynthetic tensile sample. Background technique [0002] In the existing test regulations or standards for geosynthetics, the approximate nominal strain or elongation is used for the characterization and calculation of the tensile deformation of the test, that is, the change value of the distance between the clamps at both ends of the sample is compared to the original length of the sample. Get the nominal strain value. When the tensile deformation of the geosynthetic sample is small, the difference between the nominal strain and the real strain is not large, but when the tensile deformation is large, the strain in the middle part of the geosynthetic sample and the two ends close to the clamp are not uniformly distributed, approximately The calculated nominal strain will be quite different from the real strain...

AI Technical Summary

Problems solved by technology

However, for geosynthetics with the characteristics of soft texture, large deformation, thin thickness and easy damage, and extremely uneven strain distribution, adhesive strain measurement tools, such as resistance strain gauges, often have advantages compared with geosynthetics. A large modulus will easily affect the test results of the mechanical performance test of geosynthetics; barbed strain measurement tools, such as extensometers, are likely to cause damage to the geosynthetics, thereby affecting the test; manual support is required Strain measurement tools, such as rulers, etc., obviously cannot be implemented when continuous tensile tests and multi-point measurements are required

Therefore, for the strain field measurement in the biaxial tensile test of geosynthetics, the contact strain measurement method cannot meet the requirements, but a non-contact strain field measurement device or method is needed

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