A Simplified Finite Element Joint Model Updated with Experimental Modal Features

Finite element modeling (FEM) and analysis (FEA) are commonly employed for structural design evaluation and iteration. With current technology, full-fidelity modeling of larger assemblies is often computationally prohibitive, requiring simplification of the model’s complex features. One such feature that is frequently simplified is the bolted joint, which is ubiquitous in engineering structures. However, approximate methods for modeling joints introduce inaccuracies. To understand this model-induced error, this paper explores a novel, computationally efficient method for the modeling of bolted connections. This method introduces several parameters local to the joints that can be adjusted to improve the accuracy of the model; these parameters define the size of a tied contact area and the properties of a virtual material region. To maintain computational efficiency on complex structures, this method is compatible with a linear, eigenvalue modal analysis. To test this novel method, it was applied to the finite element modeling of bolted connections in a four-story structure. Experimental modal analysis was conducted to validate the FE model. Additionally, Bayesian model calibration was used to quantify the model parameter uncertainties and update geometric and material properties. Overall, this paper presents a viable, experimentally validated method to efficiently model bolted connections in multi-connection structures.