Statistical dependence investigation related to Dowel-Type timber joints

Abstract

The design of timber connections with dowel-type fasteners is dependent on the knowledge of their mechanical behavior and failure modes. Concerning the main design parameters, the timber embedment strength and the dowel bending moment capacity are the parameters that govern the load-carrying capacity. The correlation between the timber embedment strength and the dowel bending moment capacity has not been sufficiently addressed in the literature yet. However, since they both share a common dependency to the timber density, they are probably correlated. To investigate this, traditional distribution fitting procedures, as well as copula functions, are implemented to consider the correlation between them. By doing so, it is aimed to evaluate the effectiveness of the different approaches in describing the dependence structure of the variables and their influence on the structural reliability. It was found that, for single dowel-type connections, the impact of the copulas on the results is small. It is indicated that, unless significantly nonlinear correlations exist among the data, the results obtained by applying different copula functions will probably be very close.