A method for estimating the moment capacity of bolted glulam connections with slotted-in steel plate under complex loading conditions

Accurately and rapidly estimating the moment capacity of the bolted glulam connections with slotted-in steel plate (BGCSP) under complex loading is vital for the design of timber structures. In this study, theoretical analysis was conducted to derive the equation of the final position of the rotation center of the BGCSP under combined axial force, shear force and bending moment as well as combined shear force and bending moment. Based on the European Yield Modes, the theoretical methods for the estimation of the moment capacity of the BGCSP under complex loading were developed. The validation of the proposed theoretical method for the estimation of the moment capacity was implemented. Comparing the values of the moment capacity obtained from the theoretical method proposed in this study with those obtained from the existing experimental, numerical and theoretical studies revealed that the proposed theoretical method can provide a more convenient way to estimate the moment capacity of the BGCSP. Besides, the error analysis showed that the average value and standard deviation of the errors were −0.006 and 0.107, respectively, verifying the accuracy of the predicted results of the proposed theoretical method. Furthermore, given that the BGCSP is commonly subjected to combined shear force and bending moment in practice, parametric calculation analysis focusing on the design of the BGCSP within a range of shear-to-moment ratio was conducted considering the effect of the bolt diameter, bolt arrangement, bolt spacing, edge distance, end distance and beam height. The results indicated that the bolt arrangement was the vital parameter affecting the relationship between the normalized shear force and the normalized bending moment. Eventually, an envelope function model with coefficients κ of 2.5 and ν of 1.3 was established to describe the relationship between the normalized shear force and the normalized bending moment. This provided an easy to the design of the BGCSP with different bolt arrangements under combined shear force and bending moment.