Factors Affecting Contact Pressure Distribution on Bolted Joint Interface

2016 ◽  
Vol 693 ◽  
pp. 126-133
Author(s):  
Jing Ping Liao ◽  
Ding Wen Yu ◽  
Ping Fa Feng
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Contact Radius ◽  
Joint Interface ◽  
Bolted Joint ◽  
Contact Interface ◽  
Interface Pressure ◽  
Contact Pressure Distribution ◽  
Factors Affecting ◽  
Bolt Diameter

To investigate factors affecting contact interface pressure distribution in bolted joint, a parametric model was established by ANSYS APDL language in this paper. The contact pressure distribution on bolted joint interface was obtained through interpolating and revising contact interface forces. It is observed that the position of peak interface pressure is between the edge of bolt hole and the edge of bolt head. The contact pressure linearly changes with the bolt load while the distribution trend and radius remain unchanged. When the total thickness of clamped members is fixed, the contact pressure distribution varies from concentrated to uniform with the increasing member thickness ratio, and the maximum contact radius is reached while the member thickness is equal. When one clamped member thickness is fixed, increasing the other’s thickness can also reduce the contact pressure concentration, but the effect gradually weakens. Increasing bolt diameter can slightly increase the absolute contact radius but decrease the normalized contact radius. The inclusion of a washer under the nut can slightly promote interface clamping.

An investigation into contact pressure distribution in bolted joints

2014 ◽  
Vol 228 (18) ◽  
pp. 3405-3418 ◽  
Author(s):  
JT Stephen ◽  
MB Marshall ◽  
R Lewis
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Applied Load ◽  
Plate Thickness ◽  
Operating Conditions ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Contact Pressure Distribution ◽  
Engineering Structures ◽  
Peak Value

Bolted joints are widely used in modern engineering structures and machine designs due to their low cost and reliability when correctly selected. Their integrity depends on quantitative representation of the contact pressure distribution at the interface during design. Because of the difficulty in reaching and assessing clamped interfaces with traditional experimental methods, presently bolted joint design and evaluation is based on theoretical analysis, with assumptions to quantify pressure distribution at the clamped interface, which may not represent their true operating conditions. The present work utilises a non-intrusive ultrasonic technique to investigate and quantify the pressure distribution in bolted joints. The effect of variation in plate thickness on the contact pressure distribution at bolted interfaces under varying axial loads is investigated. While it was observed that the contact pressure at the interface increases as the applied load increases, the distance from the edge of the bolt hole at which the distribution becomes stable is independent of the applied load on the bolted joint. However, the contact pressure distribution was observed to vary with the plate thickness. Although the variation in the peak value of the average contact pressure distribution in bolted joints does not depend on the plate thickness, the distance from the edge of bolt hole at which the value of the distribution becomes stable increases as the plate thickness is increased. It was also observed that the edge of the bolt head affected the position of the peak value of the contact pressure distribution at the interface, though its effect was dependent on plate thickness. Furthermore, a model based on a Weibull distribution has been proposed to fit the experimental data and a good correlation was observed.

Contact Status Analysis of Rod-Fastened Rotors With Hirth Coupling in Gas Turbines

2015 ◽  
Author(s):  
Yang Liu ◽  
Qi Yuan ◽  
Zuo Zhou
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Gas Turbines ◽  
Three Dimensional ◽  
Effect Of Temperature ◽  
Contact Method ◽  
Centrifugal Forces ◽  
Contact Interface ◽  
Contact Pressure Distribution ◽  
Tightening Force

The aim of this paper is to provide some basis for the design and assembly of a rod-fastened rotor with Hirth coupling. The rod-fastened rotor is comprised of a series of discs clamped together by a central tie rod or several tie rods on the pitch circle diameter. The key difference between a rod-fastened rotor and an integrated one is the existence of contact interfaces. The contact status of contact interface in the rod-fastened rotor is the key concern for accurate rotor dynamic analysis. Therefore, the method of accurately describing the slippage status and contact status is presented in this paper. The approach of eliminating the slippage and making the radial contact pressure distribution more uniform is also presented. According to the characteristics of Hirth coupling, one model of a turbine end rotor with Hirth coupling of a heavy duty gas turbine was built. The three-dimensional finite element contact method and non-linear behaviors such as friction were also taken into account. The effect of pre-tightening forces, centrifugal forces and overhung rim lengths on the radial slippage including initial radial slippage usi and dynamic radial slippage usd of contact interface was determined. A dimensionless coefficient cr was also defined to describe the radial contact pressure distribution of contact interface which was influenced by the values of pre-tightening forces, centrifugal forces and wheel rim lengths respectively. The results of Hirth coupling indicate that the initial radial slippage increases with the pre-tightening forces, and for a fixed pre-tightening force, usi decreased with the increase of overhung rim length. In addition, there is an optimum rim length to eliminate the dynamic radial slippage usd produced by the change of the centrifugal force. Through the analysis of contact pressure distribution, we know that the reasonable design of the load relief trough processed in the overhung rim makes the contact pressure distribution more uniform. Finally, the effect of temperature load on the radial slippage and contact pressure distribution was investigated.

Importance of Contact Pressure Distribution on Heat Transfer in Structural Joints of Machine Tools

1980 ◽  
Vol 102 (2) ◽  
pp. 159-167 ◽  
Author(s):  
M. H. Attia ◽  
L. Kops
Keyword(s):  
Heat Transfer ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Machine Tools ◽  
Thermal Contact ◽  
Contact Pressure Distribution ◽  
Structural Element ◽  
Factors Affecting ◽  
Design Calculations ◽  
Solid Bodies

Analysis of factors affecting the distribution of the contact pressure between the structural components of machine tools is presented. The effect of this distribution on the heat transfer is discussed through the visualization of a model of two solid bodies in contact. Evaluation of significance of this effect conducted on a numerical example (overarm of a milling machine) indicates that the whole temperature field of the structural element and thus its thermal deformation is affected by the contact pressure distribution. It is revealed also, that the thermal contact stresses at the joint are comparable to the mechanical ones and thus both should be considered in design calculations.

Rim Slip and Bead Fitment of Tires: Analysis and Design2

2006 ◽  
Vol 34 (1) ◽  
pp. 38-63 ◽  
Author(s):  
C. Lee
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Frictional Torque ◽  
Finite Element Analyses ◽  
Inflation Pressure ◽  
Contact Pressure Distribution ◽  
Design Modification ◽  
Iterative Design ◽  
Slip Resistance ◽  
Braking Torque

Abstract A tire slips circumferentially on the rim when subjected to a driving or braking torque greater than the maximum tire-rim frictional torque. The balance of the tire-rim assembly achieved with weight attachment at certain circumferential locations in tire mounting is then lost, and vibration or adverse effects on handling may result when the tire is rolled. Bead fitment refers to the fit between a tire and its rim, and in particular, to whether a gap exists between the two. Rim slip resistance, or the maximum tire-rim frictional torque, is the integral of the product of contact pressure, friction coefficient, and the distance to the wheel center over the entire tire-rim interface. Analytical solutions and finite element analyses were used to study the dependence of the contact pressure distribution on tire design and operating attributes such as mold ring profile, bead bundle construction and diameter, and inflation pressure, etc. The tire-rim contact pressure distribution consists of two parts. The pressure on the ledge and the flange, respectively, comes primarily from tire-rim interference and inflation. Relative contributions of the two to the total rim slip resistance vary with tire types, depending on the magnitudes of ledge interference and inflation pressure. Based on the analyses, general guidelines are established for bead design modification to improve rim slip resistance and mountability, and to reduce the sensitivity to manufacturing variability. An iterative design and analysis procedure is also developed to improve bead fitment.

One-Dimensional Contact Pressure Distribution of Radial Tires in Motion

1995 ◽  
Vol 23 (2) ◽  
pp. 116-135 ◽  
Author(s):  
H. Shiobara ◽  
T. Akasaka ◽  
S. Kagami ◽  
S. Tsutsumi
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Experimental Studies ◽  
Rolling Resistance ◽  
Leading Edge ◽  
Forward Direction ◽  
Contact Pressure Distribution ◽  
Support Ring ◽  
One Dimensional ◽  
Lowered Pressure

Abstract The contact pressure distribution and the rolling resistance of a running radial tire under load are fundamental properties of the tire construction, important to the steering performance of automobiles, as is well known. Many theoretical and experimental studies have been previously published on these tire properties. However, the relationships between tire performances in service and tire structural properties have not been clarified sufficiently due to analytical and experimental difficulties. In this paper, establishing a spring support ring model made of a composite belt ring and a Voigt type viscoelastic spring system of the sidewall and the tread rubber, we analyze the one-dimensional contact pressure distribution of a running tire at speeds of up to 60 km/h. The predicted distribution of the contact pressure under appropriate values of damping coefficients of rubber is shown to be in good agreement with experimental results. It is confirmed by this study that increasing velocity causes the pressure to rise at the leading edge of the contact patch, accompanied by the lowered pressure at the trailing edge, and further a slight movement of the contact area in the forward direction.

Analysis of the Contact Deformation of a Radial Tire with Camber Angle

1995 ◽  
Vol 23 (1) ◽  
pp. 26-51 ◽  
Author(s):  
S. Kagami ◽  
T. Akasaka ◽  
H. Shiobara ◽  
A. Hasegawa
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Contact Region ◽  
Contact Deformation ◽  
Contact Pressure Distribution ◽  
Radial Tire ◽  
Ring Model ◽  
Camber Angle ◽  
Contact Free ◽  
Good Agreement

Abstract The contact deformation of a radial tire with a camber angle, has been an important problem closely related to the cornering characteristics of radial tires. The analysis of this problem has been considered to be so difficult mathematically in describing the asymmetric deformation of a radial tire contacting with the roadway, that few papers have been published. In this paper, we present an analytical approach to this problem by using a spring bedded ring model consisting of sidewall spring systems in the radial, the lateral, and the circumferential directions and a spring bed of the tread rubber, together with a ring strip of the composite belt. Analytical solutions for each belt deformation in the contact and the contact-free regions are connected by appropriate boundary conditions at both ends. Galerkin's method is used for solving the additional deflection function defined in the contact region. This function plays an important role in determining the contact pressure distribution. Numerical calculations and experiments are conducted for a radial tire of 175SR14. Good agreement between the predicted and the measured results was obtained for two dimensional contact pressure distribution and the camber thrust characterized by the camber angle.

Measurement and Visualization of the Contact Pressure Distribution of Rubber Disks and Tires

1995 ◽  
Vol 23 (4) ◽  
pp. 238-255 ◽  
Author(s):  
E. H. Sakai
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Contact Area ◽  
Light Absorption ◽  
Lateral Force ◽  
Contact Pressure Distribution ◽  
High Definition ◽  
The Road ◽  
Close Relationship ◽  
Processing Techniques

Abstract The contact conditions of a tire with the road surface have a close relationship to various properties of the tire and are among the most important characteristics in evaluating the performance of the tire. In this research, a new measurement device was developed that allows the contact stress distribution to be quantified and visualized. The measuring principle of this device is that the light absorption at the interface between an optical prism and an evenly ground or worn rubber surface is a function of contact pressure. The light absorption can be measured at a number of points on the surface to obtain the pressure distribution. Using this device, the contact pressure distribution of a rubber disk loaded against a plate was measured. It was found that the pressure distribution was not flat but varied greatly depending upon the height and diameter of the rubber disk. The variation can be explained by a “spring” effect, a “liquid” effect, and an “edge” effect of the rubber disk. Next, the measurement and image processing techniques were applied to a loaded tire. A very high definition image was obtained that displayed the true contact area, the shape of the area, and the pressure distribution from which irregular wear was easily detected. Finally, the deformation of the contact area and changes in the pressure distribution in the tread rubber block were measured when a lateral force was applied to the loaded tire.

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