scholarly journals Bolted joint compliance analysis with account for the roughness of contact surfaces

2020 ◽  
Author(s):  
B.V. Buketkin ◽  
V.M. Zyablikov ◽  
I.E. Semenov-Ezhov ◽  
A.A. Shirshov
Keyword(s):  
Simple Model ◽  
Experimental Verification ◽  
Joint Strength ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Joint Compliance ◽  
Main Requirement ◽  
Contact Compliance ◽  
Proposed Model ◽  
Contact Surfaces

Bolted joints are widespread in various industries. They are used both in detachable and in non-detachable connections. The main requirement for bolted joints is to ensure the strength of the connection and guaranteed contact pressure on the connected surfaces, i.e. joints, during the operation of the structure. As a rule, their design and calculation do not take into account the contact compliance of surfaces, which is determined by their macro- and microroughnesses. This problem leads to an overestimation of the joint strength and an underestimation of the predicted joint compliance. The study proposes a simple model which makes it possible by calculation to take into account the effect of the roughness of the contacting surfaces on the compliance of the joint without modifying the ANSYS application package. On the example of a flange connection, an experimental verification of the adequacy of the proposed model was carried out.

EXPERIMENTAL STUDY ON SLIP COEFFICIENT OF HIGH STRENGTH BOLTED JOINT WITH METAL SPRAYED CONTACT SURFACE

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Yusuke Nakanishi ◽  
Kunitaro Hashimoto ◽  
Yasuo Suzuki ◽  
Kunitomo Sugiura
Keyword(s):  
Steel Structures ◽  
High Strength ◽  
Treatment Method ◽  
Construction Cost ◽  
Bolted Joints ◽  
Maintenance Cost ◽  
Bolted Joint ◽  
Slip Coefficient ◽  
Surface Conditions ◽  
Contact Surfaces

There are several ways to reduce the number of bolts of frictional bolted joints from the viewpoint of the construction cost and the maintenance cost for steel structures. For example, there are the ways which are strengthening the material of bolts, or increasing the slip coefficient. This study is focused on the slip coefficient with metal thermal sprayed contact surfaces. The objective of this study is to investigate the effects of different surface conditions on the slip coefficient. Therefore, slip tests were conducted in consideration of 9 patterns of surface treatment method (3 kinds of thickness, 3 kinds of material of sprayed metal).

A New Approach for Determining Bolt Load of Eccentric Bolted Joints

2014 ◽  
Vol 668-669 ◽  
pp. 115-118
Author(s):  
Xi Wang Wang ◽  
Xiao Yang Li ◽  
Xiao Guang Wang ◽  
Lin Lin Zhang
Keyword(s):  
Fatigue Loading ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Bolted Connection ◽  
New Approach ◽  
Nonlinear Variation ◽  
Linear Elastic ◽  
Proposed Model ◽  
Service Load ◽  
Interface Contact

Bolt load in a bolted connection directly influence the safety of a design in regard to both static and fatigue loading as well as in the prevention of separation in the connection. When the separating force is applied off the bolt center, 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 variation of the bolt load, the deformation etc. An analytical model is proposed to obtain the expression for the nonlinear bolt load under a separating service load. Finite element modeling is used for evaluating the accuracy of the proposed model.

Finite Element Modeling for Static and Dynamic Analysis of Structures with Bolted Joint

2006 ◽  
Vol 306-308 ◽  
pp. 547-552 ◽  
Author(s):  
Young Doo Kwon ◽  
Hyun Wook Kwon ◽  
Ji-Hoon Hwangbo ◽  
Suck Ho Jang
Keyword(s):  
Simple Model ◽  
Dynamic Analysis ◽  
Nonlinear Behavior ◽  
Bolted Joints ◽  
Contact Friction ◽  
Bolted Joint ◽  
Complicated Shape ◽  
Detailed Model ◽  
Static And Dynamic Analysis ◽  
Practical Model

To predict the accurate behavior of bolted joints, detailed 3-D modeling is needed that considers the contact friction, preload, and nonlinear behavior of joints. However, a detailed model with gap elements cannot ensure convergence due to the complicated shape, plus it is inappropriate for a dynamic analysis. Accordingly, this paper suggests three kinds of model for structures with bolted joints: (1) detailed model, (2) practical model, and (3) simple model, which can be selected based on the purpose of the analysis. Through a static experiment using a strain gauge, the accuracy of the detailed model was verified, and the results of a modal test compared with the results of the simple model to confirm its effectiveness in a dynamic analysis. In the case of a static analysis using the simple model, the analysis results almost corresponded with those of the detailed model for a part 2.5d away from the center of the bolt. Among the proposed models, the simple model has the least degree of freedom and requires 59% less memory than the detailed model.

Evaluations of the Tightening Process of Bolted Joint With Elastic Angle Control Method

2004 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Tomohiro Takaki
Keyword(s):  
Surface Roughness ◽  
Rotation Angle ◽  
Control Method ◽  
Plastic Region ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Bolt Stress ◽  
Loaded Surface ◽  
Contact Surfaces ◽  
Inclined Angle

Various clamping methods are used to tighten bolted joints and the selection is made according to its configuration, bolt size, etc. Angle control method is commonly used among them and it is usually applied when tightening bolts to the plastic region. However, elastic angle control method is sometimes used to tighten important structures, e.g., for the case where the clamping bolts are to be disassembled in a periodical inspection. In this paper, the tightening process of elastic angle control method is studied and the expression relating axial bolt force and nut rotation angle is proposed, in which the effects of surface roughness of contact surfaces and the inclined angle existing around nut loaded surface are incorporated. The validity of the proposed equation is demonstrated by experiment. It is shown that the elastic angle control method is preferably applied to the case of a bolted joint with large grip length being tightened with high bolt stress.

Representation of bolted joints in a structure using finite element modelling and model updating

2020 ◽  
Vol 14 (3) ◽  
pp. 7141-7151 ◽  
Author(s):  
R. Omar ◽  
M. N. Abdul Rani ◽  
M. A. Yunus
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Model Updating ◽  
Complex Structure ◽  
Bolted Joints ◽  
Model Parameters ◽  
Fe Model ◽  
Bolted Joint ◽  
Fe Modelling ◽  
Joint Structure

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

scholarly journals Experimental study of lateral resistance of bolted joints using Japanese cedar (Cryptomeria japonica) treated with resin impregnation

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Keita Ogawa ◽  
Satoshi Fukuta ◽  
Kenji Kobayashi
Keyword(s):  
Short Pulse ◽  
Japanese Cedar ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Yield Load ◽  
Short Pulse Laser ◽  
Resin Impregnation ◽  
Lateral Resistance ◽  
Ultraviolet Wavelength ◽  
Resistance Performance

Abstract The development of wooden joints possessing high resistance performance has become an important issue for the construction of newer buildings. This study attempts to strengthen the lateral resistance of bolted joints using the previously reported plasticizing technique. This technique consists of two processing stages: incising the surface of the wood using an ultraviolet wavelength short-pulse laser and impregnating the resin into the incised area. This technique makes it possible to plasticize only a local part of the wood surface. Bolted joint specimens were assembled using plasticized wood around the bolt hole, and the lateral tests were conducted. Acrylic monomer and urethane prepolymer were used as the impregnating resins and their incision depths were set as 4 and 10 mm. When the lateral load acted parallel to the grain, changes in the lateral resistance characteristics were observed, especially for the stiffness and yield load. For example, when acryl was used, and the incision depth was 10 mm, an increment of 73% in the yield load was observed, as compared to the non-impregnated specimens. The specimen groups impregnated with acryl exhibited greater changes in their properties than those using urethane. When loaded perpendicular to the grain, an increase in properties were observed; however, these increments were lower than those of the groups loaded parallel to the grain.

Accurate Evaluation of Bolt and Clamped Members Stiffnesses Of Bolted Joints

2021 ◽  
Author(s):  
Rashique Iftekhar Rousseau ◽  
Abdel-Hakim Bouzid ◽  
Zijian Zhao
Keyword(s):  
Finite Element ◽  
Joint Stiffness ◽  
Element Model ◽  
Fe Analysis ◽  
Bolted Joints ◽  
Analytical Models ◽  
Fe Modeling ◽  
Bolted Joint ◽  
A New Technique ◽  
External Loads

Abstract The axial stiffnesses of the bolt and clamped members of bolted joints are of great importance when considering their integrity and capacity to withstand external loads and resist relaxation due to creep. There are many techniques to calculate the stiffnesses of the joint elements using finite element (FE) modeling, but most of them are based on the displacement of nodes that are selected arbitrarily; therefore, leading to inaccurate values of joint stiffness. This work suggests a new method to estimate the stiffnesses of the bolt and clamped members using FE analysis and compares the results with the FE methods developed earlier and also with the existing analytical models. A new methodology including an axisymmetric finite element model of the bolted joint is proposed in which the bolts of different sizes ranging from M6 to M36 are considered for the analysis to generalize the proposed approach. The equivalent bolt length that includes the contribution of the thickness of the bolt head and the bolt nominal diameter to the bolt stiffness is carefully investigated. An equivalent bolt length that accounts for the flexibility of the bolt head is proposed in the calculation of the bolt stiffness and a new technique to accurately determine the stiffness of clamped members are detailed.

Viscous Friction Effect During the Process of Tightening and Loosening of Bolted Joints

2021 ◽  
Author(s):  
Qingyuan Lin ◽  
Yong Zhao ◽  
Qingchao Sun ◽  
Kunyong Chen
Keyword(s):  
Friction Coefficient ◽  
Viscous Friction ◽  
Normal Pressure ◽  
Friction Model ◽  
Bolted Joints ◽  
Critical Parameters ◽  
Bolted Joint ◽  
Sliding Velocity ◽  
Friction Effect ◽  
Bearing Friction

Abstract Bolted connection is one of the most widely used mechanical connections because of its easiness of installation and disassembly. Research of bolted joints mainly focuses on two aspects: high precision tightening and improvement of anti-loosening performance. The under-head bearing friction coefficient and the thread friction coefficient are the two most important parameters that affect the tightening result of the bolted joint. They are also the most critical parameters that affect the anti-loosening performance of the bolted joint. Coulomb friction model is a commonly used model to describe under-head bearing friction and thread friction, which considers the friction coefficient as a constant independent of normal pressure and relative sliding velocity. In this paper, the viscous effect of the under-head bearing friction and thread friction is observed by measuring the friction coefficient of bolted joints. The value of the friction coefficient increases with the increase of the relative sliding velocity and the decrease of the normal pressure. It is found that the Coulomb viscous friction model can better describe the friction coefficient of bolted joints. Taking into account the dense friction effect, the loosening prediction model of bolted joints is modified. The experimental results show that the Coulomb viscous friction model can better describe the under-head bearing friction coefficient and thread friction coefficient. The model considering the dense effect can more accurately predict the loosening characteristics of bolted joints.

scholarly journals A simple model to estimate ice ablation under a thick debris layer

2006 ◽  
Vol 52 (179) ◽  
pp. 528-536 ◽  
Author(s):  
Han Haidong ◽  
Ding Yongjing ◽  
Liu Shiyin
Keyword(s):  
Heat Flux ◽  
Simple Model ◽  
Iterative Procedure ◽  
Indirect Comparison ◽  
Tien Shan ◽  
Balance Model ◽  
Complex Phase ◽  
Proposed Model ◽  
Koxkar Glacier

AbstractThis paper presents a simple model to estimate ice ablation under a thick supraglacial debris cover. The key method employed in the model is to establish a link between the debris heat flux and the debris temperature at a certain depth when the heat transfer in the debris is described by a diffusion process. Given surface temperature, debris thermal properties and relevant boundary conditions, the proposed model can estimate mean debris temperature at interfaces of different debris layers using an iterative procedure, and then the heat flux for ice ablation. The advantage of the proposed model is that it only requires a few parameters to conduct the modeling, which is simpler and more applicable than others. The case study on Koxkar glacier, west Tien Shan, China, shows, in general, that the proposed model gives good results for the prediction of debris temperatures, except for an apparent phase shift between modeled and observed values. We suggest that this error is mainly due to complex phase relations between debris temperature and debris heat flux. The modeled ablation rates at three experimental sites also show good results, using a direct comparison with observed data and an indirect comparison with a commonly used energy-balance model.

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.

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