A new multi-scale modeling method for needled C/C composites

Abstract

Needled composites have stronger interlaminar properties compared to two-dimensional fiber composite structures due to the introduction of z-directional fibers in the fiber composite layup. An effective multi-scale finite element model is developed in this paper for the complex structure of needle-punched composites. Three scales, namely fRVE, pRVE, and lRVE, are modeled from the fiber scale, the delamination scale, and the laminate scale. using ABAQUS, periodic boundary conditions are applied to the RVEs at different scales to obtain the effective mechanical properties of various RVEs. Meanwhile, the effect of needling density on the needled composites is predicted by applying the above multi-scale model. The increase of needling density can enhance the out-of-plane effective mechanical properties of the composites, but it also weakens the in-plane effective mechanical properties. The maximum error of the elastic modulus calculation is 17.68% with that of the reference, thus verifying the rationality of the multi-scale model.

Keywords:

• C/C needled composites
• finite element model
• multi-scale
• mechanical properties

Additional information

Funding

This work is supported by Fundamental Research Program of Shanxi Province (Grant No. 202103021224111); Science and Technology on Advanced Functional Composites Laboratory, Aerospace Research Institute of Material and Processing Technology (Grant No. 6142906210406); the Natural Science Foundation of Shanxi Province (Grant No. 201903D421030); the National Natural Science Foundation of China (Grant No. 52075361); the Shanxi Province Science and Technology Major Project (Grant No. 20201102003); Central Guidance on Local Science and Technology Development Found of Shanxi Province (Grant No. YDZJSX2021A021); and the "1331 project" Key Innovation Teams of Shanxi Province. The financial contributions are gratefully acknowledged.