Cross-shaped sample for biaxial mechanical test as well as preparation method and application of cross-shaped sample

Abstract

The invention relates to a cross-shaped sample for a biaxial mechanical test as well as a preparation method and an application of the cross-shaped sample and belongs to the technical field of composite material biaxial loading tests. The whole sample is cross-shaped and comprises four loading arms, wherein each loading arm is provided with a loading arm hollow area (2), the tail end of each loading arm is a loading arm clamping end (1), and a transition area is arranged between roots of every two adjacent loading arms; a sample center area is arranged among the roots of the four loading arms, the middle area of the sample center area is a central test area (6), and a thinned transition area (5) is arranged between the central test area (6) and the roots of the loading arms. The cross-shaped sample is simple in structure and convenient to realize, stress concentration phenomena in arc transition chamfered positions of the cross-shaped sample are weaker while the central test area is higher and uniform in stress level, the biaxial stress state of the central test area is easier to realize, and initial damage occurs in the central test area.

Description

technical field [0001] The invention relates to a cross-shaped sample for biaxial mechanical testing and a preparation method thereof, belonging to the field of complex load testing of composite materials. Background technique [0002] As the most widely used composite material in engineering, fiber-reinforced composite materials are becoming more and more popular in the aerospace field. With the development and application of various advanced composite materials, the application proportion of fiber reinforced composite materials in load-bearing structures is increasing, which makes the stress state of composite materials more and more complex. Therefore, it is more and more necessary to study the strength characteristics of fiber reinforced composite materials, especially the failure characteristics under biaxial stress or multiaxial stress state, so as to ensure the safety of fiber reinforced composite material structures in use. [0003] At present, the uniaxial performa...

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Problems solved by technology

However, due to the anisotropy of the structure of the composite material itself and its weak machining characteristics, the biaxial test results are not ideal

[0005] Due to the limitation of experimental conditions in China, there has not been much research on the problem of biaxial loading of in-plane biaxial loading specimens.

So far, only some brief analyzes and tests have been done on the rationality and effectiveness of composite samples under simple biaxial loading. Did not make good progress and development

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