Non-destructive testing method for testing durability of fiber reinforced composite materials

Abstract

The invention provides a non-destructive testing method for testing the durability of fiber reinforced composite materials. The method comprises the steps of assigning a plurality of fiber reinforcedcomposite material test pieces of the same batch to one reserved test piece group and N standard test piece groups; performing a destructive strength tensile test on all reserved test pieces, and determining the tensile strengths of standard test pieces by means of a non-destructive tensile test; performing the non-destructive tensile test on all the standard test pieces for M times to obtain an average elastic modulus of the standard test pieces at the initial time; placing the standard test pieces in a test environment for aging; taking out all the standard test pieces at each aging time point, and performing non-destructive tensile test for M times so as to obtain an average elastic modulus of all the standard test pieces at the current aging time point. The method provided by the invention can avoid the influence, caused by the different initial mechanical properties of test samples, on the durability test results of the composite materials, reduces the dispersion of the test results, and improves the test precision as well as the stability and reliability of the test results.

Description

technical field [0001] The present application relates to the technical field of tensile testing of composite materials, in particular to a non-damage testing method for the durability of fiber-reinforced composite materials. Background technique [0002] For nearly half a century, reinforced concrete structures have needed to be repaired and reinforced due to various reasons, such as design errors, substandard material quality, changes in use functions, and the impact of harsh environments such as corrosion. Therefore, the civil engineering field has been devoting itself to the research and development of reinforcement and restoration materials and technologies. Due to the light weight, high strength and good corrosion resistance of Fiber Reinforced Plastic (FRP) materials, FRP materials are widely used in the repair and reinforcement of concrete structures and composite structures. [0003] With the popularization of the technology of FRP strengthening and repairing struc...

AI Technical Summary

Problems solved by technology

[0007] Composite materials are affected by factors such as the type and proportion of the constituent materials, so even the same batch of composite material specimens may have large differences in their initial mechanical properties, and composite material specimens with different proportions will undergo a certain aging period. The back section will vary, either increase or decrease, and it is difficult to test the exact net sectional area

Therefore, if the above-mentioned strength performance reduction coefficient method in the prior art is still used for composite materials, it will lead to a large dispersion of strength test results, and the mechanical performance benchmark points between different test samples are not uniform, and the corresponding reduction Coefficients can only express uncertain changes, which are less scientific and less reliable

[0008] In addition, the research on the durability of composite materials in the prior art is mainly a qualitative research, which can only study the changing trend of the durability of composite materials with the change of influencing factors in a specific environment.

Due to the diversity of composite material components and the diversity of external environments, most of the research in the prior art can only obtain some discrete data, and then use these discrete data to judge the change trend of durability performance, or to draw some Simple models, these are far from being used as the basis for quantitative design of composite durability

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