Analysis of the Tightening Process of Bolted Joint With a Tensioner: Effects of Interface Stiffness

2000 ◽  
Author(s):  
Toshimichi Fukuoka
Keyword(s):  
Diesel Engines ◽  
Pressure Vessels ◽  
Clamping Force ◽  
Structural Members ◽  
Bolted Joint ◽  
Elementary Approach ◽  
Bearing Surface ◽  
Initial Tension ◽  
Actual Operation ◽  
Contact Surfaces

Abstract Hydraulic tensioners are widely used in tightening important structural members such as large-sized diesel engines and pressure vessels. The ratio of desired clamping force to initial tension, which is termed effective tensile coefficient, is the most important factor to be predicted in the actual operation for given joint configurations. In this paper, an elementary approach to estimate this coefficient, taking the effects of interface stiffness into account, is proposed using spring elements. The influences of interface stiffness at four contact surfaces on the coefficient are discussed, and it is shown that interface stiffness of pressure flank of threads and bearing surface of nut has dominant effects on the coefficient.

Analysis of the Tightening Process of Bolted Joint With a Tensioner Using Spring Elements

1994 ◽  
Vol 116 (4) ◽  
pp. 443-448 ◽  
Author(s):  
T. Fukuoka
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Clamping Force ◽  
Structural Members ◽  
Bolted Joint ◽  
Initial Tension ◽  
Elementary Method ◽  
The Relationship

Hydraulic bolt tensioners are frequently used to tighten critical structural members with accurately controlled clamping force. The ratio of desired clamping force to initial tension is the most important factor to be predicted in advance for given joint configurations, which is termed “effective tensile coefficient” here. In this paper, an elementary and extensive approach to estimate the coefficient is proposed using spring elements, and a simple and practical equation is presented to evaluate the magnitude of “effective tensile coefficient” in terms of five spring rates of each part consisting of the joint. The relationship between “effective tensile coefficient” and grip length is investigated, including the influences of Young’s modulus of fastened plate. The validity of the elementary method proposed here is ascertained by comparing the results to those by experiment and FEM.

Finite Element Simulation of Tightening Process of Bolted Joint With a Tensioner

1992 ◽  
Vol 114 (4) ◽  
pp. 433-438 ◽  
Author(s):  
T. Fukuoka
Keyword(s):  
Finite Element ◽  
Contact Problems ◽  
Numerical Approach ◽  
Screw Thread ◽  
Clamping Force ◽  
Structural Members ◽  
The Finite Element Method ◽  
Initial Tension ◽  
Element Simulation ◽  
Design Factors

In tightening structural members with bolts or studs, hydraulic bolt tensioners are frequently used in the case where the clamping force must be controlled with high accuracy. The most important factor in the operation is the ratio of desired clamping force to initial tension applied by a hydraulic tensioner, which is termed “effective tensile coefficient” here. In this paper, a numerical approach of the tightening process is proposed using the finite element method, which can deal with axisymmetric elastic contact problems. The amounts of the coefficient are estimated for various design factors such as grip length, nominal diameter of screw thread, and coefficients of friction on contact surfaces.

Study on hysteresis and threaded fitting behavior of bolted joint with non-parallel bearing surface

2022 ◽  
Vol 168 ◽  
pp. 108655
Author(s):  
Longfei Tan ◽  
Chengyu Wang ◽  
Yang Liu ◽  
Wei Sun ◽  
Wei Zhang
Keyword(s):  
Bolted Joint ◽  
Bearing Surface

Corrosion Measuring Probes for Marine Applications

CORROSION ◽  
1961 ◽  
Vol 17 (10) ◽  
pp. 485t-491t ◽  
Author(s):  
DAVID ROLLER ◽  
WILLARD R. SCOTT ◽  
HERMAN S. PREISER ◽  
FRANK E. COOK
Keyword(s):  
Electrical Resistance ◽  
Structural Members ◽  
Condenser Tube ◽  
Exterior Surface ◽  
Preliminary Testing ◽  
Resistance Method ◽  
Service Testing ◽  
Inlet Tube ◽  
Actual Operation ◽  
Marine Applications

Abstract This paper describes the design, fabrication and preliminary testing of several types of corrosion measuring probes developed for use on maritime vessels. The probes are part of a system utilizing the electrical resistance method for continuously monitoring corrosion during actual operation. One type of probe to be described is intended for monitoring corrosion on either the exterior surface of the hull or interior structural members in large compartment. Another probe has been developed for measuring condenser tube inlet (tube end) corrosion. A third probe has been developed for measuring corrosion in crevices and pipe lines. Both laboratory and simulated service testing has been carried out. Results of these tests and the effectiveness of the probes in measuring corrosive conditions on ships are discussed. 2.4.2

scholarly journals Modeling and Simulating the Static Structural Response and Lift Off of a Preloaded Bolted Joint on a Flange

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 10
Author(s):  
Rami Alfattani
Keyword(s):  
Structural Response ◽  
Segment Length ◽  
Bolted Joint ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Bolt Preload ◽  
Gap Opening ◽  
Parametric Studies ◽  
Contact Surfaces ◽  
Lift Off

The present paper describes the structural analysis performed on a preloaded bolted joint. The first joint modeled was comprised of a conventional cylindrical flange that was sliced to simplify the analysis for two bolts in lieu of four. This involved an L-shaped flat segment flange. Parametric studies were performed using elastic, large-deformation, non-linear finite element analysis to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preload, contact surfaces, edge boundary conditions, and joint segment length in this first approach. The second model applied the previous preloaded torque on a complex flange to study the flange lift off. Joint response is reported in terms of displacements, gap opening, and surface strains. Most of the factors studied were determined to have minimal effect on the bolted joint response.

The Impact of Qualified Bolting Specialists on the Safe, Reliable Assembly and Operation of Bolted Flanged Connections

2015 ◽  
Author(s):  
A. Fitzgerald (Jerry) Waterland ◽  
David Lay ◽  
Michael Dodge
Keyword(s):  
Work Force ◽  
Pressure Vessels ◽  
Bolted Joints ◽  
Critical Area ◽  
Bolted Joint ◽  
Learning Program ◽  
Guideline Document ◽  
The Impact ◽  
Joint Assembly

Why do we certify welders but require no evidence of training or competence from those performing the critical bolted flanged joint assembly of pressure vessels and piping throughout the same industries? To remedy this situation ASME has recently released the first comprehensive standard in ASME PCC-1-2013 Appendix A that establishes uniform criteria, not just for the quality of the bolted joints but for the workers who assemble them. To support this critical training and qualification standard, ASME Training & Development has created a unique blended learning program for pipe fitters and mechanics to become Qualified Bolting Specialists (QBS), per the requirements outlined in PCC-1-2013 Appendix A. The purpose of this technical presentation is to explain the opportunities presented by this new standard and how industry can benefit from a better-trained work force in this critical area of bolted joint assembly. The authors have been integrally involved in the development of both the PCC-1 guideline document, and the ASME qualification program, and can authoritatively answer industry’s questions.

Numerical Study of an Impusively Loaded Vessel Containing Double Versus Single Closure Bolt Patterns

2017 ◽  
Author(s):  
Joseph E. D. Hess
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Numerical Study ◽  
Axial Loading ◽  
Element Model ◽  
Pressure Vessels ◽  
Bolted Joint ◽  
Single Row ◽  
Asme Code ◽  
Calculation Results

Impulsively loaded pressure vessels are often closed using a bolted joint configured in a double staggered row pattern. The bolted joint design must maintain the placement of the vessel opening covers to support the structural integrity of the shell and also provide the necessary preload of sealing surfaces for leak prevention. Good design practice suggests configuring tensile loaded bolted joints with a double rows pattern in order to minimize prying against the bolt head induced by localized moments. Double bolt row patterns allow moments induced by load offsets to be reacted through contact of the faying surfaces of the bolted members and if separation occurs by differential axial loading of the two bolt rows. This acts to reduce direct prying of the mated members against the bolt heads. Material cost and operational time savings could be realized if a single bolt row design with acceptable performance was implemented. In this paper a detailed finite element model is described and calculation results are presented for two vessel configurations subjected to an impulsive load; a double staggered 64 bolt pattern and a single row 32 bolt pattern. Finite element results are compared to each other and to the rules of ASME Code Case 2564 in Section VIII, Division 3. Special attention is given to the loading induced in the bolts and to the relative deflection of faying surfaces containing seals. It will be shown that reducing the bolt count per opening from 64 to 32 results in increased peak response of the bolts, seal opening gaps, and shell. Nonetheless a single row bolt pattern does appear feasible and within the bounds of the Code Case.

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