Tension Failure Simulation of Notched Composite Laminate Using Floating Node Method Combined with In-Situ Effect Theory

Abstract In order to model the progressive failure of laminates under tensile load, the finite element model adopting the floating node method combined with In-Situ effect strength theory is developed in this paper. The floating node method is based on the original finite elements to assign more additional degree of freedoms on the edges or nodes. In this way, it can realize crack propagation explicitly and prevent the singularity caused by the integration of body elements at the damage points. The calculation method of In-Situ strength theory based on the assumption of fracture mechanics is introduced and deduced, which improves the accuracy of the failure strength prediction. Two kinds of notched composite laminates’ tensile experiments were carried out. Experiment results show that different ply sequences ([453/903/-453/03]s and [45/0/-45/90]3s) have different failure strength and failure progress. In this paper, the reliability of the model is verified by comparing the experimental results with the simulation results. The comparison results demonstrate that this model can realize the explicit crack propagation and predict the failure strength precisely. In addition, this model can represent some failure modes such as fiber breakage, matrix damage, and delamination, which were observed from experimental phenomenon. The traditional failure criteria compared to the improved criteria's accuracy is significantly improved. It demonstrated that the analysis in considering the In-Situ effect is very necessary.