Modeling of bolted beam utilizing modified joint element and identification of contact parameters at the joint

Research on the modeling of bolted connection structures primarily centers on the characterization of the connection interface. Accurate equivalent modeling of the connection interface is crucial for the effective modeling of bolted connection structures. This article considers the misalignment between the bolt plane and the beam plane, and establishes a modified joint element representing the bolted connection by using the series-stiffness method. The contact stiffness in this modified joint element are identified using a genetic algorithm with an “emperor selection” strategy. The bolted connection beam model is achieved by refining the Euler-Bernoulli beam model through the incorporation of a modified joint element. The maximum error between the model calculation results and experimental results for each order of natural frequency is 2.39 %. This demonstrates the feasibility of accurately characterizing the bolted connection beam through the utilization of the modified joint element for equivalent modeling. This research proposes a modeling method for bolted connection beams that accounts for the misalignment between the bolt plane and the beam plane, significantly enhancing modeling accuracy.