Nonlinear Modeling and Identification of an Aluminum Honeycomb Panel with Multiple Bolts

Abstract

This paper focuses on the nonlinear dynamics modeling and parameter identification of an Aluminum Honeycomb Panel (AHP) with multiple bolted joints. Finite element method using eight-node solid elements is exploited to model the panel and the bolted connection interface as a homogeneous, isotropic plate and as a thin layer of nonlinear elastic-plastic material, respectively. The material properties of a thin layer are defined by a bilinear elastic plastic model, which can describe the energy dissipation and softening phenomena in the bolted joints under nonlinear states. Experimental tests at low and high excitation levels are performed to reveal the dynamic characteristics of the bolted structure. In particular, the linear material parameters of the panel are identified via experimental tests at low excitation levels, whereas the nonlinear material parameters of the thin layer are updated by using the genetic algorithm to minimize the residual error between the measured and the simulation data at a high excitation level. It is demonstrated by comparing the frequency responses of the updated FEM and the experimental system that the thin layer of bilinear elastic-plastic material is very effective for modeling the nonlinear joint interface of the assembled structure with multiple bolts.

Non-linear modeling and parameter identification of a bolted joint using substructure synthesis theory

“…Thus, while modelling constructed systems, the natural dynamics interface relationships must be taken into account [4]. An improved understanding of nonlinear behaviour in bolted joints can be achieved by enhancing the models with cubic stiffness nonlinearity, resulting in a more accurate depiction of the actual behaviour of bolted joints [5,6]. An complete four-parameter model that takes into account non-Gaussian surface flaws ,accurately describes the nonlinear stiffness behaviour of bolted joints [7].…”

“…An innovative analytical model was created in order to determine the real correlation among load and deformation of a single bolted lap joint. Also natural frequencies and mode shapes were additionally identified [19], achieved modelling of aluminium honeycomb panel for identification of the parameters using several bolts [6,20] nonlinear dynamic characteristics under transient excitation [21] and using describing function inversion for determining weak non-linear system [22,23]. An identification method for analytical and numerical issues using the dynamic characteristic equation for linear interface parameters is presented by Jalali [24].…”