scholarly journals Mechanical Behaviors of Bolted Joint during Tightening Using Torque Control.

1998 ◽  
Vol 41 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Toshimichi FUKUOKA ◽  
Tomohiro TAKAKI
Keyword(s):  
Torque Control ◽  
Bolted Joint ◽  
Mechanical Behaviors

Elasto-Plastic Analysis of Bolted Joint During Tightening Process

1999 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Tomohiro Takaki
Keyword(s):  
Plastic Deformation ◽  
Axial Force ◽  
High Stress ◽  
Torque Control ◽  
Shear Stresses ◽  
Clamping Force ◽  
Bolted Joint ◽  
Mechanical Behaviors ◽  
Practical Applications ◽  
Thread Root

Abstract A bolted joint is subjected to high stress concentration at the thread root because of its complicated geometry involved. Plastic regions are produced around the bottom of thread root, even under relatively low bolt axial force. It is predicted that the plastic deformation thus produced might affect such important mechanical behaviors of bolted joint as load distributions along threads, the relationships between bolt axial force and angle of nut rotation, etc. In many practical applications, bolts are tightened with considerably high clamping force, especially when tightening critical structures. Thus, it is considered that numerical studies taking the effects of plastic deformation into account are extremely important. However, many previous studies have only dealt with a bolted joint under pure tension. When tightening bolted joints with torque control shear stresses are generated in addition to the tensile stress due to bolt clamping force. In this study, mechanical behaviors of bolted joint during tightening with torque control are analyzed by FEM as an elasto-plastic contact problem, where three-dimensional analysis is conducted employing two dimensional model with each node having three degrees of freedom.

scholarly journals Investigation on the Optimum Tightening Force of Bolted Joint in Torque Control Method

1973 ◽  
Vol 39 (462) ◽  
pp. 748-752
Author(s):  
Kaoru HONGO ◽  
Isamu YOSHIMOTO ◽  
Gendai ETO ◽  
Tsutomu SASAKI
Keyword(s):  
Control Method ◽  
Torque Control ◽  
Bolted Joint ◽  
Tightening Force

Influence of the axial position of the external load on the mechanical behavior of the bolted lap joint with different materials

2019 ◽  
Vol 20 (6) ◽  
pp. 623
Author(s):  
Peng He ◽  
Zhiqiang Fan ◽  
Xiangyu Yu ◽  
Zhansheng Liu
Keyword(s):  
Finite Element ◽  
Mechanical Behavior ◽  
External Load ◽  
Axial Load ◽  
Axial Position ◽  
Primary Concern ◽  
Bolted Joint ◽  
Mechanical Behaviors ◽  
Element Analysis ◽  
Design Guideline

The axial mechanical behaviors of the bolted joint are a primary concern of the bolted joint structures. The axial load position has obvious influence on the axial mechanical behaviors of the bolted joint with different materials, while it can not be considered by the analytical method yet. The objective of this work is to fill this gap. With the pressure cone assumption, the axial resilience of the stress zones is derived, and the detailed formulation of the load introduction factor is proposed. The mechanical behavior of the bolted joint subjected to external axial load is formulated and compared with finite element analysis. Results show that the distance between load planes has apparent influence on the axial mechanical behaviors of the bolted joint. In particular for the bolted joint with different materials, the axial positions of the external load have obvious effect on the mechanical behavior. Comparisons with the finite element results indicate that with the proposed formulation of load introduction factor, the analytical formulations could predict the mechanical behavior of the bolted joint with different materials accurately. The proposed formulation of load introduction factor in this work could be an effective supplement of the heavy duty bolt design guideline.

Finite Element Analysis of the Thermal and Mechanical Behaviors of a Bolted Joint

2005 ◽  
Vol 127 (4) ◽  
pp. 402-407 ◽  
Author(s):  
Toshimichi Fukuoka
Keyword(s):  
Heat Flow ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Thermal Contact ◽  
Numerical Procedure ◽  
Numerical Approach ◽  
Pressure Vessels ◽  
Bolted Joint ◽  
Mechanical Behaviors ◽  
Flow Through

Mechanical and thermal behaviors of the bolted joint subjected to thermal load are analyzed using axisymmetric FEM, where the effects of thermal contact resistance at the interface and heat flow through small gap are taken into account in order to accurately evaluate the variations of bolt preloads. It is expected that the numerical procedure proposed here provides an effective means for estimating the strength of such critical structures as pressure vessels, internal combustion engines, steam and gas turbines, etc. An experimental equation that can compute the thermal contact coefficient at the interface composed of common engineering materials has been proposed in the previous paper. In this study, a simple equation for evaluating the amount of heat flow through small gap is shown by defining apparent thermal contact coefficient. Accordingly, a numerical approach has been established, which can accurately analyze the thermal and mechanical behaviors of a bolted joint, by incorporating the two kinds of thermal contact coefficients into FE formulation. By use of the FE code thus developed, it is shown that only a slight difference in coefficients of linear expansion among the joint members significantly affects the variations of bolt preloads. The validity of the numerical approach is demonstrated by experimentation.

Mechanical Behaviors of Bolted Joint in Various Clamping Configurations

1998 ◽  
Vol 120 (3) ◽  
pp. 226-231 ◽  
Author(s):  
T. Fukuoka ◽  
T. Takaki
Keyword(s):  
Stress Concentration ◽  
Bolted Joints ◽  
Elastic Contact ◽  
Bolted Joint ◽  
Mechanical Behaviors ◽  
Stress Concentrations ◽  
Tightening Torque ◽  
Pitch Error ◽  
Manufacturing Errors ◽  
Multi Body

In a bolted joint, failures usually initiate at the first root of the bolt thread. However, rupture around the bolt head is sometimes reported for a tap bolt because of high stresses produced by tightening torque applied to the bolt head. It is also well known that manufacturing errors of internal threads in a tapped hole are generally much larger than those of external threads, thus leading to the failures concerned. In this paper, mechanical behaviors of bolted joints in various clamping configurations are analyzed using FEM as multi-body elastic contact problem, and the effects of nominal diameter, friction and pitch error upon stress concentrations are evaluated for through bolts, studs, and tap bolts. It is then quantitatively estimated on the effectiveness of “recessed internal threads” for reducing the stress concentration occurred around the far end of bolt hole. In addition, the tightening process and strength of a bottoming stud, which have seldom been studied despite favorable performance in preventing stress concentration at the runout of threads, are also investigated.

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