Connection design method of honeycomb plate-rod composite structure: Experimental study and theoretical analysis

The connection design method of plate-rod composite structure is very important for the cooperative work of plate and rod. In this study, ten kinds of plate-rod composite structures of different connection methods, connection spacings, and plate thicknesses were designed to examine the connection performance of composite structure. The applicable finite element analysis methods of three connection methods were obtained by comparing the calculation results of finite element simplification models. The influence of connection spacing, connector diameter and plate thickness on the connection performance of three connection methods was studied by parametric analysis. The optimized shear bearing capacity formula of three connection methods were proposed based on the connection performance test and the design specifications at home and abroad. The bending bearing capacity formula of composite structure were proposed by theoretical derivation and finite element analysis, and the relevant parameters were fitted by the Backward Propagation (BP) algorithm in neural network. The results shown that the connection performance of Self-Piercing Riveting connection is obviously better than that of one-side bolt and core-pulling rivet connection, and the bearing capacity is increased by about 6 % and 10 %. The connector solid (So-1-1), solid simplified beam (So-3-1 and So-3-2), and shell simplified beam (Q-1) modeling method can better simulate the one-side bolt connection, and the error is within 3 %. The connector solid (So-1-2), solid beam (So-2-1), embedded (So-4-1), and shell simplified beam (Q-1) are suitable for core-pulling rivet connection, and the error is within 5 %. All the finite element analysis simplification methods can accurately simulate the Self-Piercing Riveting connection except for the Q-2, and the error is within 2 %. The bearing capacity of the composite structure increases with the increase of the connector diameter, the decrease of the connection spacing and the increase of the plate thickness. The optimized shear bearing capacity formula are more suitable for practical application, and the error of the bending bearing capacity formula of composite structure is within 5 %, which provides a certain reference for the design of honeycomb plate-rod composite structure and the revision of relevant specifications in the future.