Establishment and Verification of Nonlinear Bolt Head Connection Stiffness Theoretical Model Based on Levenberg-Marquardt Method

Abstract

Although some scholars have established the calculation method of bolt head connection characteristics, the method contains fewer influence factors; the calculation accuracy is not high, and the general applicability is limited. Based on the Levenberg Marquardt optimization algorithms, a more accurate calculation model of bolt head connection stiffness is proposed in this paper. The model includes many parameters such as bolt head thickness, equivalent diameter, bolt diameter, thickness of connected parts, elastic modulus of bolt and elastic modulus of connected parts. Through the finite-element verification and comparison with the results of the Fears Alkatan method, the calculation results of the bolt head connection stiffness calculation model in this paper are effective and accurate, which provides a universal calculation model for calculating the bolt head connection stiffness of various parameters, and fills the shortage of inaccurate calculation of the current theoretical model of bolt head stiffness.INDEX TERMS bolt head, stiffness, finite element, connected parts.

Finite Element Analysis of Elastoplastic Elements in the Iwan Model of Bolted Joints

“…However, there is no feasible apparatus to measure the evolution of contact conditions under mixed-mode loading. On the basis of experiments, many theoretical models have been proposed such as the Iwan model [ 6 ], LuGre model [ 7 ], Valanis model [ 8 ], 4-stage shear model [ 9 ], and Lu model [ 10 ], where the Iwan model is widely used for simplicity. To characterize the residual stiffness, Song et al [ 11 ] modified the constitutive model of the Iwan model.…”

FEM Modelling Approaches of Bolt Connections for the Dynamic Analyses of an Automotive Engine

“…In [19], four kinds of FEM bolt models were suggested for a structure with a bolted joint and, through a comparison with simple static experiment and modal test results, the effectiveness and usefulness of the bolt models were confirmed. Based on the Levenberg-Marquardt optimization algorithms, a more accurate calculation model of bolt head connection stiffness is proposed in [20], providing a universal assessment model for calculating the bolt head connection stiffness of various parameters.…”