Method for testing axial compression performance of carbon fiber composite material and constitutive model

Abstract

The invention discloses a method for testing the axial compression performance of a carbon fiber composite material and a constitutive model. The method comprises the following steps: firstly, carrying out axial quasi-static compression on a carbon fiber composite material test part by adopting an MTS universal testing machine to obtain low-strain-rate compression performance; then, carrying out axial dynamic compression experiment on the carbon fiber composite material test part through an SHPB experiment device to obtain high-strain-rate compression performance; secondly, verifying the rationality of a quasi-static experiment by adopting a composite material mixing law, verifying the accuracy of a dynamic compression experiment by adopting a waveform change relationship, and proposing ajoint buckling strength calculation formula; and finally, introducing a strain rate item to fit an experimental result to obtain the stress-strain constitutive model of axial compression of the carbonfiber composite material. The constitutive model obtained by the invention can accurately describe the mechanical properties of the axial compression of the carbon fiber composite material, and can provide reference for numerical simulation and axial compression performance test of other similar materials.

Description

technical field [0001] The invention belongs to the field of compression performance research, and in particular relates to a test method and a constitutive model for the axial compression performance of carbon fiber composite materials. Background technique [0002] Epoxy resin is the most commonly used thermosetting polymer in carbon fiber-reinforced polymer composites. Carbon fiber-reinforced epoxy resin composites made of it as a matrix have high modulus, high strength, high tensile strength, fatigue resistance, and high temperature resistance. , Corrosion resistance, electric shock resistance, low density, strong design and other advantages, it is widely used in automobiles, ships, aviation, aerospace, construction and other fields, and is called "black gold". The development of carbon fiber is very rapid. At present, there are T300, T700, T800 and other series. In recent years, composite materials containing layers, multi-directional weaving, and various carbon fibers...

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Problems solved by technology

Scholars' research turned to the constitutive research of ply, and added the continuous damage effect, which made the research usually limited to the description of the phenomenon and the updated structure. However, the establishment of the basic unidirectional carbon fiber compression constitutive model is still insufficient.

[0003] Cao Cuiwei et al [Cao Cuiwei, Li Zhaoqian, Li Hejun, et al. Thermophysical and Ablation Properties of C / C Composites Braided by Shaft Rod Method[J]. Solid Rocket Technology, 2011,34(1):113-118.] Yes The compression and bending properties of three-dimensional four-way C / C composite materials braided by the shaft-rod method have been studied, the compressive stress-strain curve of the material has been observed, and the failure process of the material has been given, but the constitutive model has not been studied

Li Biao et al [Li Biao, Yang Yongxin, Yue Qingrui, et al. Research on the mechanical properties of carbon fiber composite rods [J]. Industrial Architecture, 2013, 43(6): 5-8.] studied the properties of carbon fiber long rods through experiments Tensile properties, pointing out that the tensile failure modes of long carbon fiber rods are brittle fracture and explosive fracture, and drawing the tensile stress-strain curve; C.SOUTIS[Soutis C.Compression testing of pultruded carbon fiber-epoxycylindrical rods[J]. Journal of Materials Science,2000,35(14):3441-3446.] carried out the compression test of extruded carbon fiber-epoxy cylindrical rod, the material is T300 / 828, the diameter is 4mm, the effective length is 13mm, and the compression rate is 1mm / min; The similarity between these two documents is that the specimens are long-dimension specimens and only static tension and compression experiments are carried out, and the constitutive model is not studied

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