Evaluation method for uniformity of continuous-fiber-reinforced composite resin

Abstract

The invention provides an evaluation method for the uniformity of continuous-fiber-reinforced composite resin. According to a technical scheme in the invention, the method comprises the following main steps: step 1, acquiring a continuous-fiber-reinforced composite, cutting out samples at to-be-detected positions, wherein when the samples are to be cut out, it is required that the axial direction of most fibers on each selected cross section is perpendicular to the cross section; step 2, randomly selecting a sample, selecting test areas on a polished cross section; and step 3, after selection of the test areas, successively testing the nanometer mechanical hardness of each test area, wherein when one test area is to be tested, a nanometer indentation probe is used for scanning the three-dimensional morphology of the test area, then test points are selected from the test area, and the nanometer hardness of each test point is tested successively. Thus, the method can test the performance of the composite resin in a nano-scale microscopic level for evaluation of microscopic uniformity of the resin; and the method has a wide application scope and is applicable to acquisition of microscopic mechanical data of samples located at different areas and positions, so multiple information of integral, local and microscopic uniformity of composite samples can be obtained.

Description

technical field [0001] The invention relates to the technical field of performance testing of composite materials, in particular to a method for evaluating resin uniformity of continuous fiber reinforced composite materials. Background technique [0002] Continuous fiber-reinforced composite materials have excellent specific strength and specific stiffness, so they are used as structural materials in aircraft, ships, automobiles and other fields more and more widely. Thermosetting resins represented by epoxy resin are widely used in fiber-reinforced composite materials. In use, its strength, toughness, defect characteristics, interface and other factors determine the overall performance of the composite material. [0003] The uniformity of the composite resin affects the performance of the composite material. This uniformity includes the uniformity of the whole, local and even microscopic scales. For example, the "off-site" toughening technology used in the resin transfer mo...

AI Technical Summary

Problems solved by technology

In the prior art, the direct mechanical information of the resin cannot be obtained by applying methods such as infrared spectroscopy, and it is actually difficult to identify the difference in the infrared spectrum when the curing degree of the resin is high; other material analysis methods in the prior art, such as TEM, SEM, energy spectrum, Analytical methods such as spectroscopy have corresponding limitations. SEM has advantages in analyzing the inhomogeneity of the microscopic multi-phase structure, but it cannot analyze the micromechanical inhomogeneity caused by different curing degrees.