Experimental and numerical investigation of T-joints with multiwalled carbon nanotubes

Combined experimental and numerical methods were used to study the mechanical properties of multiwalled carbon nanotubes (MWCNTs) enhanced composite T-joints in this article. Herein, an enhanced interface model was created based on the interface mechanical properties with MWCNTs obtained by a flatwise tension test and a single-lap shear test. Then, the finite element model of composite T-joints with MWCNTs was developed with a cohesive zone model to study the damage initiation, evolution, and final failure process of T-joints. Meanwhile, a quasi-static tensile test of the T-joints was carried out to compare with the numerical analysis results. The study results showed that the out-of-plane tensile strength and the in-plane shear strength of MWCNTs enhanced composite increased by up to 26.3%(@3 g/m²) and 23.4%(@2 g/m²), respectively. The properties of the filler, which was the weakest part of the T-joints, can be enhanced by adding MWCNTs. The overall bearing capacity of the T-joints was 18.8%(@2 g/m² MWCNTs) increase under tensile loading. Predictions given by the FEM of composite T-joints were in good agreement with the experimental results. This article provides a method for analyzing and predicting the complex composite structure enhanced with MWCNTs, which can be used for functional structure design.