Method for testing biaxial stretching performance of composite material laminate

Abstract

The invention provides a method for testing biaxial stretching performance of a composite material laminate. The method comprises three steps: firstly, a biaxial stretching test piece of a composite material laminate which is optimized by a design scheme is selected, and the test piece comprises a clamping zone, an elliptical transition zone, a central thinning chamfering zone, and a central thinning calibration zone; then, a biaxial stretching test is carried out for the biaxial stretching test piece of the composite material laminate, and a load-displacement curve of the clamping zone and a load-strain curve of a central thinning calibration zone during a loading process are measured; finally, a finite element method is used for processing test data, and modulus and strength during biaxial stretching of the composite material laminate are obtained. The method has the beneficial effects that the optimized scheme of the biaxial stretching test piece of a composite material laminate and the method for testing biaxial stretching performance of the composite material laminate are designed, and the scheme and the method are simple and convenient for application.

Description

technical field [0001] The invention provides a method for testing the biaxial tensile properties of a composite material laminate, belonging to the field of composite material test methods. Background technique [0002] Compared with traditional metal materials, composite materials have higher specific strength and specific stiffness, and have been widely used in various structures of aircraft and spacecraft. It is a very critical step in structural design to evaluate the mechanics of composite laminates through experiments and theoretical methods. load situation. At present, the research on the biaxial stress state of composite materials is mostly theoretical, and rarely involves the test of the biaxial stress state. The reason is that there is no ready-made test platform for the biaxial test, and it is very difficult to implement. There are no test standards for reference. Composite structures are often subjected to complex stress conditions during service, and the exi...

AI Technical Summary

Problems solved by technology

At present, the research on the biaxial stress state of composite materials is mostly theoretical, and rarely involves the test of the biaxial stress state. The reason is that there is no ready-made test platform for the biaxial test, and it is very difficult to implement. No test standard available for reference

Composite structures are often subjected to complex stress conditions during service, and the existing design analysis methods are based on uniaxial mechanical properties for mechanical modeling and failure prediction, and only rely on uniaxial mechanical properties for design and analysis. It is difficult to achieve sufficient safety and reliability, which will affect the utilization efficiency and potential of composite materials. Reliable biaxial test data are urgently needed for verification or correction

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