The influence of interface on the structural stability in 3D concrete printing processes

Due to its advantages in rapid manufacturing, Three-dimensional concrete printing (3DCP) technology has developed rapidly in the past several decades. However, there are still many problems to be solved in the printing process. For example, many 3DCP structures failed during printing processes due to stability problems. There are still various shortcomings in the current stability research, among which the most significant is the inability to accurately predict the printing failure height. In this paper, a numerical model is established to predict the buckling failure of a 3DCP cylinder under its dead weight, and the effect of the interfacial area on the structural stability is analyzed. The results showed that the concept of the interfacial area solves the problem that the failure height predicted by the simulation is not consistent with experiments. Second, more detailed 3DCP structural behaviors are discussed, including the influence of the layer cross-sectional geometry on the stability, the influence of the structural deformation on the print path, and the development of the failure mode. Finally, the influences of the relevant printing parameters on the structural stability are evaluated. The results indicate that the interface is an important index that should be used to evaluate the structural stability in 3D concrete printing processes.