A Numerical Quasi-Static Method for the Identification of Frictional Dissipation in Bolted Joints

2012 ◽  
Author(s):  
Hugo Festjens ◽  
Gael Chevallier ◽  
Jean-Luc Dion
Keyword(s):  
Static Method ◽  
Bolted Joints ◽  
Mode Shapes ◽  
Bolted Joint ◽  
Lap Joint ◽  
Element Analysis ◽  
Linear Dynamics ◽  
Frictional Dissipation ◽  
Static Approach ◽  
Modal Coordinates

The hereby paper investigates a way to compute the micro-sliding dissipations that occurs in built-up structure using modal coordinates. This numerical method extends the former quasi-static approach to modal displacements through the use of finite element analysis. Considered structures are supposed to behave linearly except for a lumped bolted joint. It is firstly assumed that mode shapes of such structures are few affected by contact non-linearities in joint interfaces. This assumption allows to apply the normal eigenmodes of the linearized structure as boundary conditions on a model reduced to the bolted joint. The method relies on a corrected quasi-static analysis associated with the Masing rules. Those assumptions enables to avoid the considerable numerical expense due to non-linear dynamics. In order to improve the simulation, a mode shapes correction is also implemented. The formulation of the method is detailed and investigated on the classical lap-joint benchmark.

scholarly journals Nonlinear Axial Stiffness Characteristics of Axisymmetric Bolted Joints

1990 ◽  
Vol 112 (3) ◽  
pp. 442-449 ◽  
Author(s):  
I. R. Grosse ◽  
L. D. Mitchell
Keyword(s):  
Finite Element ◽  
Linear Theory ◽  
Design Theory ◽  
Joint Stiffness ◽  
Bolted Joints ◽  
Axial Stiffness ◽  
Outer Diameter ◽  
Bolted Joint ◽  
Element Analysis ◽  
Stiffness Characteristics

A critical assessment of the current design theory for bolted joints which is based on a linear, one-dimensional stiffness analysis is presented. A detailed nonlinear finite element analysis of a bolted joint conforming to ANSI standards was performed. The finite element results revealed that the joint stiffness is highly dependent on the magnitude of the applied load. The joint stiffness changes continuously from extremely high for small applied loads to the bolt stiffness during large applied loads, contrary to the constant joint stiffness of the linear theory. The linear theory is shown to be inadequate in characterizing the joint stiffness. The significance of the results in terms of the failure of bolted joints is discussed. A number of sensitivity studies were carried out to assess the effect of various parameters on the axial joint stiffness. The results revealed that bending and rotation of the joint members, interfacial friction, and the bolt/nut threading significantly influence the axial stiffness characteristics of the bolted joint. The two-dimensional, axisymmetric finite element model includes bilinear gap elements to model the interfaces. Special orthotropic elements were used to model the bolt/nut thread interaction. A free-body-diagram approach was taken by applying loads to the outer diameter of the joint model which correspond to internal, uniformly distributed line-shear and line-moment loads in the joint. A number of convergence studies were performed to validate the solution.

Nonlinear Behavior of Preloaded Bolted Joints Under a Cyclic Separating Load

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Xianjie Yang ◽  
Sayed A. Nassar ◽  
Zhijun Wu ◽  
Aidong Meng
Keyword(s):  
Finite Element ◽  
Deformation Behavior ◽  
Nonlinear Behavior ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Linear Elastic ◽  
Plastic Deformation Behavior ◽  
Service Load ◽  
Joint Material

The nonlinear plastic deformation behavior of a clamped bolted joint model under a separating service load is investigated using analytical, finite element, and experimental techniques. An elastic-plastic model is used for the bolt material while the joint material remains in the linear elastic range. Both the analytical and finite element analysis (FEA) models investigate the variation in the tension of a preloaded bolt due to a separating service load that acts with an offset from the bolt center. Experimental verification is provided for both the analytical and finite element results on the bolt tension variation, clamp load variation and the clamp load loss caused by the incremental plastic bolt elongation under cyclic separating force.

Load Transfer Analysis of Cracked Bolted Joints

2010 ◽  
Vol 118-120 ◽  
pp. 147-150
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Yong Gao ◽  
Wen Lin Liu ◽  
Zhong Hu Jia
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a cracked bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of load transfer were compared with results from finite element analysis. The results show that three-dimensional finite element model of cracked bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of hole mod and crack on the load transfer behaviour of single lap bolted joints. The results show that hole mode has big effect on load transfer of cracked bolted joint. In the whole progress of crack growth, the load transfer through bolt 1 decrease, and almost all of the load duduction of bolt 1 transfer into blot 2 rather than into bolt 3.

Influence of Vibration Behavior on the Energy Dissipation of the Bolted Joints

2019 ◽  
Author(s):  
Wenxiang Xu ◽  
Ligang Cai ◽  
Zhifeng Liu ◽  
Qiang Cheng ◽  
Ying Li
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Vibration Frequency ◽  
Cyclic Load ◽  
Fractal Theory ◽  
Bolted Joints ◽  
Mode Shapes ◽  
Bolted Joint ◽  
Engineering Structures ◽  
Stick Slip

Abstract Bolted joints are widely used for the mechanical assembly of engineering structures. It has been widely observed that fasteners turn loose when subjected to dynamic loads in the form of vibration or cyclic loading. Preload relaxation of threaded fasteners is the main factor that influences the joint failure under normal cyclic loading, but it is difficult to monitor the energy dissipation between the interface of the bolted joint. This paper presents an energy dissipation model for the bolted joint based on two-degree-of-freedom vibration differential mathematical model. A non-uniform pressure at the interface is considered and the resulted distinct stick-slip transitions along the contact interface are presented. The parameters of the model is calculated by using the fractal theory and differential operator method. Experiments are conducted to verify the efficiency of the proposed model. The results show that the theoretical mode shapes are in good agreement with the experimental mode shapes. According to the change of cyclic load and vibration frequency, the vibration response and the law of energy dissipation under different factors can be obtained. The results show that the vibration frequency and cyclic load are the main factors affecting the energy dissipation between interfaces. The energy dissipation of the contact surface of the bolted joints account for the main part of the energy dissipation of the bolted structure. As the preload increases, its energy dissipation decrease gradually. The results provide a theoretical basis for reducing micro-slip at the bolted joints interface.

Nonlinear Deformation Behavior of Clamped Bolted Joints Under a Separating Service Load

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Sayed A. Nassar ◽  
Xianjie Yang ◽  
Satya Vijay Teja Gandham ◽  
Zhijun Wu
Keyword(s):  
Finite Element ◽  
Deformation Behavior ◽  
Nonlinear Deformation ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Analysis Study ◽  
Linear Elastic ◽  
Service Load ◽  
Interface Contact

The nonlinear deformation behavior of clamped bolted joints under a separating service load is investigated using finite element and experimental techniques. Although the materials for the bolted joint remain in the linear elastic range, the interface contact area between the clamped plates is sensitive to both the magnitude and the location of the separating force. This often causes nonlinear deformation behavior of the bolted joint. This finite element analysis study investigates the variation in the tension of a tightened bolt and the corresponding change in the joint clamp load due to a separating service load that is placed at various distances from the bolt center. The separating force is symmetrically placed at locations (from the bolt center) that are equal to 3–5 times the nominal diameter of the bolt. Experimental verification of the finite element results is provided.

Parametric Analysis Mechanical Properties of Bolted Joints

2010 ◽  
Vol 97-101 ◽  
pp. 3924-3927 ◽  
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Zhong Hu Jia ◽  
Yong Gao ◽  
Wen Lin Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of surface strains and load transfer ratio(LTR) were compared with results from finite element analysis. The results show that three-dimensional finite element model of bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of different parameters on the mechanical behaviour of single lap bolted joints. The results show that straight hole, small bolt diameter, and big hole pitch are selected first for bolted joint if other conditions allowed, and effect of bolt material on LTR of joint is small for small load. Interference and pre-stress should be strictly controlled for bolted joints in order to attain the best fatigue capability of lap joint.

Assessing Structural Safety of Bolted Joints Subject to Cyclic Loading Using Advanced Nonlinear FEA

2014 ◽  
Vol 891-892 ◽  
pp. 827-832
Author(s):  
John Miles Alden ◽  
Peter Hendrik Brand
Keyword(s):  
Finite Element Analysis ◽  
International Standards ◽  
Bolted Joints ◽  
Structural Safety ◽  
Bolted Joint ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Fatigue Design ◽  
Standard Design ◽  
Joint Parameters

The concepts of structural safety embedded in recognised international standards for the fatigue design of bolted joints, such as VDI 2230 Part 1, are examined and challenged. This is done by means of theoretical investigation of the behaviour of bolted joints using non-linear finite element analysis. Potential differences between actual bolted joint parameters and behaviour, and implicit design assumptions, are reviewed and their effect on the structural safety of bolted joints in operating equipment examined. An approach to the fatigue design of bolted joints is presented which incorporates alternative concepts of structural safety and uses advanced CAE methods as part of the standard design process.

Development of a Method for Measuring Damping in Bolted Joints

2011 ◽  
Author(s):  
Hugh Goyder ◽  
Philip Ind ◽  
Daniel Brown
Keyword(s):  
Signal Processing ◽  
Computer Simulations ◽  
Vibration Damping ◽  
Bolted Joints ◽  
Significant Source ◽  
Bolted Joint ◽  
Lap Joint ◽  
Experiment Data ◽  
Joint Behaviour

Bolted joints are a significant source of vibration damping but are extremely difficult to model within computer simulations. In order to make progress, good quality experiment data is needed to provide a basis for modelling and an understanding of the mechanisms involved. An apparatus for measuring damping in a lap joint has been developed in which bolted joints are exercised by swinging masses in a resonant configuration. The apparatus is set into vibration and then released so that the vibration decays with the bolt damping controlling the decay. After some signal processing the energy lost per cycle is extracted. The repeatability of the bolted joint behaviour is an issue of concern and this is examined by analysing a series of tests. Although largely successful the system probably applies too large a force to the joint which exhibits some slip which then contributes to the lack of repeatability observed.

Numerical Modeling and Experimental Validation of Bolted Lap Joints With 1D Hysteresis Finite Elements

2009 ◽  
Author(s):  
J. Abad ◽  
J. M. Franco ◽  
L. Lezaun ◽  
F. J. Martinez
Keyword(s):  
Numerical Modeling ◽  
3D Modeling ◽  
Laboratory Tests ◽  
Experimental Validation ◽  
3D Model ◽  
Lap Joints ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Lap Joint ◽  
3D Numerical Model

The work presented in this paper is part of a larger project for the modeling of dynamic behavior in bolted joints, and it is a further work on the adjustment of bolted joint 3D numerical model. This work shows the study and conclusions of the numerical modeling of a bolted lap joint by means of 1D hysteresis finite element and its validation with dynamical tests. The modeled joint is made up of two plates with a bolt, nut and washer. The behavior curve of the hysteresis element used was obtained by means of a 3D model of the joint, whose parameters and validation were carried out from the results of quasi-static laboratory tests. This procedure could be advantageously extended to any other lap joint given that its computational requirements are less than those required for a detailed 3D modeling.

Strength Prediction of Double-Lap Bolted Joints of Woven Fabric CFRP Composite Plates Using Hashin Formulations

2015 ◽  
Vol 802 ◽  
pp. 290-294
Author(s):  
Hilton Ahmad ◽  
Mustafa Abbas Abed
Keyword(s):  
Failure Modes ◽  
Composite Plates ◽  
Bolted Joints ◽  
Woven Fabric ◽  
Strength Prediction ◽  
Bearing Failure ◽  
Bolted Joint ◽  
Element Analysis ◽  
Bearing Failures ◽  
Cfrp Composite

Failure modes in composite plates with bolted joint configuration include net-tension, shear-out and bearing failures. Few analytical and numerical approaches in strength prediction frameworks of composite plates with bolted joints were reported in the literatures. Present works are dealing with strength prediction in bearing failure of woven fabric CFRP plates with double lap bolted joint configurations by modeling 3D finite element analysis framework. The pre-processing stage is modeled using commercial ABAQUS CAE package and takes into account all parts interactions, clamping pressure and friction contact. Testing series are following the experimental works found from the literatures with variation of plate width to hole diameter (W/d) ratios and incorporated with finger-tight clamp-up. Hashin failure criterion was implemented as constitutive modeling in current analysis, based on ply-by-ply approaches found to be more appropriate phenomenon in bearing failure. The strength prediction results demonstrated good agreement with all experimental datasets particularly with bearing failures as compared with previously reported work, used stress concentration approach found to be accurate in net-tension failure only.

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