Numerical Analysis on Mechanical Property of Bolted Joint

2013 ◽  
Vol 834-836 ◽  
pp. 1459-1463
Author(s):  
Lihua Yang ◽  
Zhi Li ◽  
Lie Yu
Keyword(s):  
Mechanical Property ◽  
Finite Element ◽  
Numerical Analysis ◽  
Axial Force ◽  
Transverse Load ◽  
Clamping Force ◽  
Bolted Joint ◽  
Stress Strain ◽  
Contact Models

The bolted joint is the important fastening parts of structures. Its fatigue and self-loosing will affect the safety of the system. In this paper, the finite element contact models are built to analyze the mechanical property of bolted joint numerically. The stress, strain and clamping force when the bolted joint is subjected to preload, axial force and transverse load are investigated. The results show that the bolt is the most dangerous part of bolt-nut connected member. The clamping force of bolted joint will gradually lose with the increasing loading cycles of cyclic transverse load which generally explains the stress loosing rule of bolted joint.

Finite Element Modeling of Self-Loosening of Bolted Joints

2004 ◽  
Author(s):  
Ming Zhang ◽  
Yanyao Jiang ◽  
Chu-Hwa Lee
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Bending Moment ◽  
Shear Loading ◽  
Transverse Load ◽  
Fe Model ◽  
Bolted Joint ◽  
Cyclic Bending ◽  
Second Stage ◽  
Cyclic Bending Moment

A three-dimensional finite element (FE) model with the consideration of the helix angle of the threads was developed to simulate the second stage self-loosening of a bolted joint. The second stage self-loosening refers to the graduate reduction in clamping force due to the back-off of the nut. The simulations were conducted for two plates jointed by a bolt and a nut and the joint was subjected to transverse or shear loading. An M12×1.75 bolt was used. The application of the preload was simulated by using an orthogonal temperature expansion method. FE simulations were conducted for several loading conditions with different preloads and relative displacements between the two clamped plates. It was found that due to the application of the cyclic transverse load, micro-slip occurred between the contacting surfaces of the engaged threads of the bolt and the nut. In addition, a cyclic bending moment was introduced on the bolted joint. The cyclic bending moment resulted in an oscillation of the contact pressure on the contacting surfaces of the engaged threads. The micro-slip between the engaged threads and the variation of the contact pressure were identified to be the major mechanisms responsible for the self-loosening of a bolted joint. Simplified finite element models were developed that confirmed the mechanisms discovered. The major self-loosening behavior of a bolted joint can be properly reproduced with the FE model developed. The results obtained agree quantitatively with the experimental observations.

The method of bolt axial force looseness monitoring and control by piezoelectric ceramics in bolted joint structures

2021 ◽  
pp. 095440622110398
Author(s):  
Xinyao Sun ◽  
Jinggan Shao ◽  
Yang Zhou ◽  
Ci Yuan ◽  
Yang Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Active Control ◽  
Axial Force ◽  
Piezoelectric Ceramic ◽  
Control Method ◽  
Piezoelectric Effect ◽  
Guided Wave ◽  
Clamping Force ◽  
Monitoring And Control ◽  
Wave Signal

Aiming at the problem of bolt looseness in structures, this paper proposes an active control method of axial force monitoring through guided wave and axial force compensation via the inverse piezoelectric effect of a piezoelectric ceramic gasket. Based on the finite element model, the propagation process of guided wave wave in bolted connectors is analyzed, which shows that the transmitted wave energy increases with the increase of bolt clamping force. The analysis of the stress-strain characteristics of the axially polarized and radially polarized piezoelectric ceramic gasket shows that the axially polarized piezoelectric ceramic gasket is more suitable for the control of bolt clamping force. The finite element analysis of the application of piezoelectric ceramic gasket in bolt axial force control shows that the power of guided wave signal increases monotonously with the increase of loaded electric field strength. In accordance with these theoretical methods and research, an active control system for bolt axial force is established in this experiment. The system monitors the power of the guided wave signal in real time and controls the axial force of the bolt by adjusting the intensity of the piezoelectric effect, which achieves an accurate control effect.

Finite Element Modeling of Self-Loosening of Bolted Joints

2006 ◽  
Vol 129 (2) ◽  
pp. 218-226 ◽  
Author(s):  
Ming Zhang ◽  
Yanyao Jiang ◽  
Chu-Hwa Lee
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Bending Moment ◽  
Shear Loading ◽  
Transverse Load ◽  
Fe Model ◽  
Bolted Joint ◽  
Cyclic Bending ◽  
Second Stage ◽  
Cyclic Bending Moment

A three-dimensional finite element (FE) model with the consideration of the helix angle of the threads was developed to simulate the second stage self-loosening of a bolted joint. The second stage self-loosening refers to the gradual reduction in clamping force due to the back-off of the nut. The simulations were conducted for two plates jointed by a bolt and a nut and the joint was subjected to transverse or shear loading. An M12×1.75 bolt was used. The application of the preload was simulated by using an orthogonal temperature expansion method. FE simulations were conducted for several loading conditions with different preloads and relative displacements between the two clamped plates. It was found that due to the application of the cyclic transverse load, microslip occurred between the contacting surfaces of the engaged threads of the bolt and the nut. In addition, a cyclic bending moment was introduced on the bolted joint. The cyclic bending moment resulted in an oscillation of the contact pressure on the contacting surfaces of the engaged threads. The microslip between the engaged threads and the variation of the contact pressure were identified to be the major mechanisms responsible for the self-loosening of a bolted joint. Simplified finite element models were developed that confirmed the mechanisms discovered. The major self-loosening behavior of a bolted joint can be properly reproduced with the FE model developed. The results obtained agree quantitatively with the experimental observations.

scholarly journals REGULARITIES OF THE LINING STRESS-STRAIN STATE DURING OF THE PYLON METRO STATION CONSTRUCTION

2021 ◽  
pp. 19-27
Author(s):  
D. O. BANNIKOV ◽  
V. P. KUPRII ◽  
D. YU. VOTCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Strain State ◽  
Finite Element Models ◽  
Bending Moments ◽  
Stress Strain ◽  
Normal Forces ◽  
Stress Strain State ◽  
Station Structure

Purpose. Perform numerical analysis of the station structure. Take into account in the process of mathematical modeling the process of construction of station tunnels of a three-vaulted station. Obtain the regularities of the stress-strain state of the linings, which is influenced by the processes of soil excavation and lining construction. Methodology. To achieve this goal, a series of numerical calculations of models of the deep contour interval metro pylon station was performed. Three finite-element models have been developed, which reflect the stages of construction of a three-vaulted pylon station. Numerical analysis was performed on the basis of the finite element method, implemented in the calculation complex Lira for Windows. Modeling of the stress-strain state of the station tunnel linings and the soil massif was performed using rectangular, universal quadrangular and triangular finite elements, which take into account the special properties of the soil massif. Station tunnel linings are modeled by means of rod finite elements. Findings. Isofields of the stress-strain state in finite-element models reflecting the stages of construction are obtained. The vertical displacements and horizontal stresses that are characteristic of a three-vaulted pylon station are analyzed. The analysis of horizontal stresses proved that at the stage of opening of the middle tunnel the scheme of pylon operation is rather disadvantageous. The analysis of bending moments and normal forces was also carried out and the asymmetry of their distribution was noted. Originality. Based on the obtained patterns of distribution of stress-strain state and force factors, it is proved that numerical analysis of the station structure during construction is necessary to take measures to prevent or reduce deformation of frames that are in unfavorable conditions. Practical value. In the course of research, the regularities of changes in stresses, displacements, bending moments and normal forces in the models of the pylon station, which reflect the sequence of its construction, were obtained.

scholarly journals Life analysis of the bolted joint

2019 ◽  
Vol 254 ◽  
pp. 02004
Author(s):  
Milan Sapieta ◽  
Peter Sulka
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Fatigue Damage ◽  
Computational Models ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Computation Model ◽  
Life Analysis ◽  
Element Method

The paper deals with the fatigue damage calculation of 2 types of computation model of bolted joints. The study is performed via a numerical analysis with support of finite element method (FEM) software ANSYS. One model was created with a thread on the bolt, another was only bolt with cylindrical surfaces, the second model was greatly simplified. It will be evaluated the fatigue damage for both types of models. Subsequently both types of computational models will be compared in dependence on the accuracy of the results and the speed of the calculation. There are also the theoretical backgrounds for preloaded bolted joint, which was used for calculation of preload load prescribed on body of screws.

Estimation of the accuracy of numerical analysis for the deformed state of power structures of technical objects

2018 ◽  
Author(s):  
А.Н. Рогалев ◽  
С.В. Доронин ◽  
В.В. Москвичев
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Safety Factor ◽  
Stiffness Matrix ◽  
Strain State ◽  
Power Structures ◽  
Safety Factors ◽  
Rounding Errors ◽  
Stress Strain ◽  
Stress Strain State

Под силовыми конструкциями понимают технические устройства, составленные из различных частей, воспринимающие комплекс эксплуатационных нагрузок в штатных и аварийных режимах нагружения. При решении прикладных задач исследования напряженно-деформированных состояний силовых конструкций важна оценка степени близости к точному приближенного решения, полученного на вполне определенной сетке конечных элементов с конечной величиной шага сетки. С учетом влияния ошибок округления сходимость метода конечных элементов контролировать сложно: при большом числе конечных элементов решение может расходиться из-за накапливающихся ошибок округления, даже если условия сходимости выполняются. Описанное в статье применение методов обратного анализа ошибок позволяет достаточно точно контролировать точность численных оценок деформированного состояния силовых конструкций, что подтверждают расчеты, выполненные для практических задач. The solution of applied problems of technogenic safety, survivability, risk and protection is performed for structures which are close to limiting states. These states are characterized by decreasing safety factors down to one. In this case a mistaken estimation for safety factor may cause the situation when the calculated safety factor will be greater than one but the real safety factor will be less than one. Safety factors estimation is performed on the basis of calculation for stress-strain state characteristics. Thus, the issues of accuracy and reliability of determining stresses and deformations are an integral part of the problem of man-made safety. In the numerical analysis of the stress-strain state, the stiffness matrix of the design model is formed, the dimension of which reaches up to tens of millions. A large number of computations for tasks of this dimension is presumably leading to significant rounding errors. Ensuring the grid convergence of results by decreasing the grid spacing is inconsistent with the growth of computational errors due to rounding. For finite element analysis of power structures of technical objects, methods of a posteriori reverse error analysis are proposed that control the effect of rounding errors on the result when solving a solving system of linear algebraic equations. The coefficient matrix of this system is the stiffness matrix of the finite element model. The basic idea is to obtain and solve a system of equations with a known exact solution. Comparison of the results of exact and numerical solutions allows us to estimate the magnitude of the error.

The Numerical Analysis of Accuracy of Hydraulic Leg Cylinder in Modeling Using Solid Works Simulation

2015 ◽  
Vol 770 ◽  
pp. 456-460 ◽  
Author(s):  
G.D. Buyalich ◽  
A.V. Anuchin ◽  
A.A. Dronov
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Strain State ◽  
Research Work ◽  
Simulation Software ◽  
Central Angle ◽  
Stress Strain ◽  
Maximum Performance ◽  
Solid Works

The research work on the influence of an angle α at centre and the finite element sizes in modeling a hydraulic leg cylinder has been done to determine the stress-strain state by FEM using SolidWorks Simulation software. Based on the analysis results the reasonable values of the central angle and finite elements for the cylinder and weld have been defined in terms of the smallest error and maximum performance computation.

scholarly journals ANALYSIS OF FEATURES OF APPLIED SOFTWARE “LIRA” IN CALCULATIONS OF NON-CIRCULAR TUNNEL LININGS

2019 ◽  
pp. 41-50
Author(s):  
V. P. KUPRIY ◽  
O. L. TIUTKIN ◽  
P. YE. ZAKHARCHENKO
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Software Package ◽  
Strain State ◽  
Element Model ◽  
Finite Element Models ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Finite Element Model

Purpose. The article examines the effect on the stress-strain state of the parameters of the finite-element model created in the “Lira” software package in a numerical analysis of non-circular outlined tunnels. Methodology To achieve this goal, the authors developed finite element models of the calotte part of the mine during the construction of a double track railway tunnel using “Lira” software. In each of the models in the “Lira” software package, the interaction zone with temporary fastening was sampled in a specific way. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. In the finite element models, the values of deformations and stresses in the horizontal and vertical axes, as well as the maximum values of the moments and longitudinal forces in the temporary fastening were obtained. A comparative analysis of the obtained values of the components of the stress-strain state with a change in the parameters of the finite element model was carried out. The graphs of the laws of these results from the discretization features of the two models were plotted. The third finite element model with a radial meshing in the zone of interaction of temporary support with the surrounding soil massif was investigated. Originality It has been established that in the numerical analysis of the SSS of a tunnel lining of a non-circular outline, its results substantially depend on the shape, size and configuration of the applied finite elements, on the size of the computational area of the soil massif, and also on the conditions for taking into account the actual (elastic or plastic) behavior of the soil massif.  Practical value. The features of discretization and the required dimensions of the computational area of the soil massif were determined when modeling the “lining – soil massif” system, which provide sufficient accuracy for calculating the parameters of the stress-strain state of the lining.

Numerical Analysis for an Novel Hooke Hinge Based on ANSYS

2016 ◽  
Vol 693 ◽  
pp. 378-384
Author(s):  
Xiao Qian Qi ◽  
Xue Wu Hong ◽  
Jian Zhao ◽  
Qing Sen Xie
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Stress Strain ◽  
Strain Behavior ◽  
Hinge Model ◽  
Data Switching ◽  
Element Method

This paper utilizes SolidWorks to establish accurate Hooke hinge model and imports it into ANSYS using the data switching interface between SolidWorks and ANSYS. The stress-strain behavior of the Hooke hinge is analyzed using finite element method, and the reliability and stability of the structure is evaluated, which provides some theoretical guidance for the design of Hooke hinge.

Self-Loosening Behavior of the Nut Due to Tension Change Considering the Inclination of Bearing Surface

2021 ◽  
Author(s):  
Yasumasa Shoji
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Relative Displacement ◽  
The Self ◽  
The Other ◽  
Transverse Load ◽  
Finite Element Analyses ◽  
Bearing Surface ◽  
Tension Change ◽  
Surface Inclination

Abstract Self-loosening behavior is a topic which many researchers are tackling and the principle is coming clearer. Self-loosening occurs mainly when transverse load is applied to the bolt/nut system and the loosening also occurs when such other loads are applied as impact of the bolt (NAS3350 test type) or temperature difference between bolt and nut. The author reproduced the phenomena by using finite element analyses and found the self-loosening is caused by radial relative displacement between bolt and nut threads. On the other hand, some researchers say the self-loosening occur when the tension changes repeatedly while others say it doesn’t. This axial force phenomenon is not yet clear even in experiment. In this paper, the self-loosening phenomenon by the tension change is examined using Finite Element Analyses. The results show that the self-loosening depends on the inclination of the bearing surface. The loosening does not occur when the inclination of the bearing surface is small enough and it occurs when the inclination is large. As the inclination of the bolt head and nut is allowed within the engineering tolerance and flanges rotate when it fastened making the bolt head or nut bearing surface inclination, the self-loosening may happen for any bolts in nature if tension changes repeatedly.

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