Effect of washer size and tightening torque on the performance of bolted joints in composite structures

2006 ◽  
Vol 73 (3) ◽  
pp. 310-317 ◽  
Author(s):  
U.A. Khashaba ◽  
H.E.M. Sallam ◽  
A.E. Al-Shorbagy ◽  
M.A. Seif
Keyword(s):  
Composite Structures ◽  
Bolted Joints ◽  
Tightening Torque

Dynamic Characteristics of Plastic Plates With Bolted Joints

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Akira Saito ◽  
Hideyoshi Suzuki
Keyword(s):  
Dynamic Characteristics ◽  
Vibration Mode ◽  
Acrylonitrile Butadiene Styrene ◽  
Bolted Joints ◽  
Modal Testing ◽  
Analytical Models ◽  
Plate Motion ◽  
Tightening Torque ◽  
Modeling Strategy ◽  
Torque Values

Abstract This paper discusses the dynamic characteristics of plastic plates with bolted joints. The effects of tightening torque on the modal properties of the plates are investigated. Experimental and numerical modal analyses have been conducted on the plates made of acrylonitrile butadiene styrene (ABS), that are clamped by bolted joints. First, the effect of tightening torque on the vibration mode of the plates is investigated by experimental modal analyses. Modal testing has been conducted for various tightening torque values, and the relationships between the modal parameters and the tightening torques are discussed. Second, the effects of tightening torque on the vibration mode are studied by using analytical models for the bolted joints based on the finite element method (FEM). Based on the comparisons between the experimental and the numerical results, a modeling strategy for the boundary conditions between the plates is introduced and its validity is discussed. From both experimental and numerical studies, it is shown that the natural frequencies of the structures with bolted joints tend to converge to specific values as tightening torque increases. Moreover, it is also shown that when modeling the bolted plates by FEM, the inter-plate motion should be constrained by a boundary condition to properly suppress the out-of-phase motion of the plates.

Improvement of Axial Tension Distribution of Bolted Joints Tightened by Calibrated Wrench Method From Viewpoint of Quality and Process Control Using Elliptical Confidence Limit

2019 ◽  
Author(s):  
Soichi Hareyama ◽  
Ken-ichi Manabe ◽  
Satoshi Kobayashi
Keyword(s):  
Process Control ◽  
Statistical Method ◽  
Confidence Limit ◽  
Bolted Joints ◽  
Independent Random Variables ◽  
Tension Stress ◽  
Bolted Joint ◽  
Tightening Torque ◽  
Tension Distribution ◽  
Axial Tension

Abstract When tightening a large number of bolted joints, the calibrated wrench method is used. Since this method is indirect, the axial tension varies greatly in many cases. However, the calibrated wrench method is still widely used because of the simplicity of the tool and easy standardization. When the tightening torque and axial tension are considered to be two independent random variables, the axial tension (stress) is distributed within an elliptical confidence limit. Conventionally, it is thought that the shape of this distribution is a rhombus. Considering the permitted limit for a working load (stress) on a bolted joint, the elliptical variation has a larger margin to the yield point than that of a conventional rhombus. On the basis of this feature, we show in this paper that a higher tightening target torque and a higher axial tension can be set than before. By applying the elliptical confidence limit, one can obtain higher tightening torque and initial axial tension than the conventional values within a smaller range of variations. In this study, in the case of tightening a large number of bolted joints at factories and so forth, tightening reliability is considered as a problem associated with quality or process control and a probabilistic statistical method is investigated. Finally, we carry out analysis to establish the optimum tightening torque for bolted joints.

Stress analysis of multi-bolted joints for FRP pultruded composite structures

2012 ◽  
Vol 94 (12) ◽  
pp. 3769-3780 ◽  
Author(s):  
Luciano Feo ◽  
Gianfranco Marra ◽  
Ayman S. Mosallam
Keyword(s):  
Stress Analysis ◽  
Composite Structures ◽  
Bolted Joints

scholarly journals A modified Arcan test for mixed-mode loading of bolted joints in composite structures

2018 ◽  
Vol 187 ◽  
pp. 203-211 ◽  
Author(s):  
Garth M. Pearce ◽  
Congyuan Tao ◽  
Yong H.E. Quek ◽  
Nayeem T. Chowdhury
Keyword(s):  
Composite Structures ◽  
Mixed Mode ◽  
Bolted Joints ◽  
Mixed Mode Loading

Distributed Strain Monitoring for Damage Evolution in CFRP Bolted Structures with Embedded Optical Fibers

2013 ◽  
Vol 558 ◽  
pp. 252-259 ◽  
Author(s):  
Nobuo Takeda ◽  
Shu Minakuchi ◽  
Takeyuki Nadabe
Keyword(s):  
Optical Fibers ◽  
Composite Structures ◽  
Large Scale ◽  
Permanent Deformation ◽  
Bolted Joints ◽  
Element Analysis ◽  
Internal Damage ◽  
Aerospace Applications ◽  
Strain Change ◽  
Distributed Strain

The authors proposed fiber-optic-based damage monitoring of carbon fiber reinforced plastic (CFRP) bolted joints. Optical fibers were embedded along bolt holes and strain change along the optical fiber induced by internal damage was measured by a Brillouin Optical Correlation Domain Analysis (BOCDA), which is a high spatial resolution distributed strain sensing system. This study began by investigating damage modes of CFRP bolted joints after bearing failure. Effective embedding positions of optical fibers were then proposed and their feasibility was evaluated by finite element analysis simulating the damage propagation in the bolted joint and consequent strain change. Finally, verification tests were conducted using specimens with embedded optical fibers at various positions. It was clearly shown that damage could be detected using residual strain due to fiber-microbuckling (kinking) damage or permanent deformation of neighboring plies. Furthermore, damage size and direction could be estimated from the change in the strain distribution. The system developed is quite useful for a first inspection of large-scale composite structures in aerospace applications.

scholarly journals ESTIMATIVE OFCORRELATIONS BETWEEN TIGHTENING TORQUE AND ASSEMBLY FORCE OF BOLTED JOINTS THROUGH MEASUREMENTS AND COMPUTATIONAL SIMULATIONS

2018 ◽  
Author(s):  
João G. Farias ◽  
Alex Pizzatto ◽  
Vitor Shimada ◽  
Thiago Zanotto ◽  
Rodrigo Pedroso ◽  
...  
Keyword(s):  
Bolted Joints ◽  
Computational Simulations ◽  
Tightening Torque

scholarly journals Identification of Pre-Tightening Torque Dependent Parameters for Empirical Modeling of Bolted Joints

2021 ◽  
Vol 11 (19) ◽  
pp. 9134
Author(s):  
Yu Tian ◽  
Hui Qian ◽  
Zhifu Cao ◽  
Dahai Zhang ◽  
Dong Jiang
Keyword(s):  
Experimental Data ◽  
Thin Layer ◽  
Empirical Equation ◽  
Model Updating ◽  
Bolted Joints ◽  
Empirical Modeling ◽  
Bolted Joint ◽  
Tightening Torque ◽  
Torque Wrench ◽  
Interface Parameters

The vibration characteristics of bolted structures are crucially affected by the pre-tightening torque. An approach for identifying the pre-tightening torque dependent stiffness parameters of bolted joints is proposed in this paper. Firstly, the interface of the bolted joint is characterized by the thin layer element with the isotropic material property, and the parameter value of the property is assigned relative to the distance from the center of the bolt; the influence of the bolt is ignored. Secondly, the model updating method is adopted to identify the parameters of thin layer elements using experimental data, and modal data under different values of pre-tightening torque in the range of 2 N·m~22 N·m are obtained; the torque wrench is used to determine the pre-tightening torque in the modal test. Finally, after identifying the material parameters using partial experimental data on pre-tightening torque range, the empirical equation of the interface parameters with the pre-tightening torque parameter is obtained by curve fitting and the rest of the experimental data are used to verify the accuracy of the fitted empirical equations. It is concluded that this method can obtain all the parameters of the equivalent thin layer elements within a certain range of pre-tightening torque, which can provide a reference for the empirical modeling of bolted structures, improve modeling efficiency and reflect the characteristic performance of real structural dynamics.

THE INFLUENCE OF TIGHTENING TORQUE ON MODAL PARAMETERS OF STRUCTURES WITH BOLTED JOINTS

2020 ◽  
Author(s):  
Estênio Fuzaro de Almeida ◽  
Luccas Miguel ◽  
Rafael de Oliveira Teloli ◽  
Samuel da Silva
Keyword(s):  
Bolted Joints ◽  
Modal Parameters ◽  
Tightening Torque
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