New Approach for Engineering Design of Bolted Joints Using Over-Elastic Behaviour

2005 ◽  
Author(s):  
C. Friedrich ◽  
J. Panthel ◽  
T. Bohlender
Keyword(s):  
Engineering Design ◽  
Contact Pressure ◽  
Bolted Joints ◽  
High Loading ◽  
Elastic Behavior ◽  
Elastic Behaviour ◽  
New Approach ◽  
Loading Level ◽  
Component Systems ◽  
Critical Materials

The behavior of bolted joints in component systems with relatively small fastening systems, critical materials or with high loading level often shows significant yielding effects with reduction of preload. Thus, poor reliability or even failures are possible. This problem requires an adaptation of the established analytical engineering design methods. A new approach with consideration of over-elastic behavior and preload history is proposed. Examples refer to magnesium components, contact pressure and tightening with angular control.

A New Approach for Determining Joint Stiffness of Bolted Joints

2014 ◽  
Vol 670-671 ◽  
pp. 1041-1044 ◽  
Author(s):  
Xi Wang Wang ◽  
Xiao Yang Li ◽  
Lin Lin Zhang ◽  
Xiao Guang Wang
Keyword(s):  
Accurate Determination ◽  
Joint Stiffness ◽  
Fatigue Loading ◽  
Bolted Joints ◽  
Analytical Models ◽  
Bolted Connection ◽  
New Approach ◽  
Axisymmetric Model ◽  
Force Equilibrium

Joint member stiffness 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. Thus, the accurate determination of the stiffness is of extreme importance to predict the behavior of bolted assemblies. In this paper, An analytical 3D axisymmetric model of bolted joints is proposed to obtain the joint stiffness of Bolted Joints. Considering many different analytical models have been proposed to calculate the joint stiffness, the expression based force equilibrium can be a easy way to choose the best expression for the joint stiffness as a judgment criteria.

scholarly journals Criticality and LCA – Building comparison values to show the impact of criticality on LCA

2019 ◽  
Vol 8 (4) ◽  
pp. 304 ◽  
Author(s):  
Björn Koch ◽  
Fernando Peñaherrera ◽  
Alexandra Pehlken
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Resource Depletion ◽  
Resource Consumption ◽  
Impact Indicator ◽  
New Approach ◽  
Critical Materials ◽  
The Impact ◽  
The Eu ◽  
Abiotic Depletion

Including criticality into Life Cycle Assessment (LCA) has always been challenging to achieve but desirable to accomplish. In this article, we present a new approach for the evaluation of resource consumption of products by building comparison values based on Life Cycle Impact Assessment (LCIA) combined with weighted criticality values to show the direct impacts of criticality on LCA results. For this purpose, we develop an impact indicator based on the Abiotic Depletion Potential (ADP) of natural resources and use the two main parameters defined by the EU to determine the criticality of a material - the economic importance and the supply risk – in our case studies to build the Criticality Weighted Abiotic Depletion Potentials (CWADPs), one for each parameter. These indicators allow identifying and measuring the impacts of criticality when comparing the results of resource depletion using the ADP methodology and the results that incorporate criticality. The comparison of the CWADPs to the corresponding EU criticality values and its thresholds it reflects the equivalent criticality of the assessed product. This information reflects the impacts of criticality on LCA and assesses the total resource consumption of critical materials in a system.Keywords: Life Cycle Assessment, criticality, resources, materials, sustainability indicator

Genetic Algorithms in Fuzzy Engineering Design

1999 ◽  
Author(s):  
Ralf Schleiffer ◽  
Hans-Jürgen Sebastian ◽  
Erik K. Antonsson
Keyword(s):  
Engineering Design ◽  
Clustering Algorithm ◽  
Computer Application ◽  
Test Problems ◽  
Important Class ◽  
New Approach ◽  
Design Task ◽  
Evolutionary Technique ◽  
The Given ◽  
Real World Problems

Abstract Problems in the field of engineering design represent an important class of real world problems that typically require a fuzzy and imprecise representation. This article presents and discusses a new approach to model this type of problem, by incorporating linguistic descriptions together with a variety of user-defined trade-off strategies. An interactive computer application is introduced, using stochastic optimization to solve the design task by producing a specially desired output under the given environmental conditions which are partly caused by the personal preferences of the engineer and by the expectations of the customer. It utilizes a randomized evolutionary technique, made suitable for the class of problems at hand, to generate and to optimize design solutions that are later identified by a clustering algorithm. Moreover test problems that were solved by the application are considered. In all cases the good solutions were obtained by evaluating only an extremely small fraction of all possible designs.

On the Nature of O-Rings in Contact With Rough Surfaces

1988 ◽  
Vol 110 (4) ◽  
pp. 632-637 ◽  
Author(s):  
W. E. Warren ◽  
J. G. Curro ◽  
D. E. Amos
Keyword(s):  
Theoretical Analysis ◽  
Root Mean Square ◽  
Contact Pressure ◽  
Contact Force ◽  
Rough Surfaces ◽  
Fundamental Importance ◽  
Elastic Behavior ◽  
Surface Irregularity ◽  
Mean Square ◽  
Irregular Surfaces

This work provides a theoretical analysis of the elastic behavior of an O-ring compressed between two rigid plates with irregular surfaces. Relations between deflection, contact force and contact pressure are obtained. The contact pressure, which is of fundamental importance in establishing criteria for effective sealing, is dependent upon both the amplitude and wavelength of the surface irregularity. This analysis suggests that surfaces in contact with O-ring seals should be characterized by the root mean square slope Δq in addition to the usual Ra which depends on amplitude only.

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.

Sensitivity Investigation of Specimen Shape on Elastic Behaviour of Perforated Plate

2009 ◽  
Author(s):  
Chang-Hoon Ha ◽  
Tae-Jung Park ◽  
Moo-Yong Kim ◽  
Kwang-Sang Seon ◽  
Jae-Mean Koo ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Perforated Plate ◽  
Type Specimen ◽  
Elastic Behavior ◽  
Elastic Behaviour ◽  
Element Analysis ◽  
Bending Tests ◽  
The Finite Element Analysis ◽  
Specimen Shape

There are various types of tube support plates installed in a steam generator according to the component designer’s preference. Most widely used types of tube support plates are BTSP (broached tube support plate), ATSG (advanced tube support grid), and the eggcrate. In this study, trefoil BTSP specimens made of ASME stainless steel are analyzed and tested. This study is to investigate the effect of specimen shape on an elastic behavior of trefoil BTSP through the compression and bending tests. Prior to the compression and bending tests of BTSP specimens, the equivalent elastic properties of BTSP unit cell are analyzed by the finite element analysis according to the different loading orientation as well as size of the model. Autodesk® Inventor™ software was used to make an analytical model and ANSYS® software was used for the finite element analysis and post-processing. Five and three different shapes of trefoil BTSP specimens are machined and utilized for the compression and bending (4-point and 3-point side bending) tests, respectively. Through the finite element analyses, compression, and bending tests, the equivalent elastic modulus of trefoil BTSP specimen is suggested to be 6,254MPa (907ksi) and the equivalent Poisson’s ratio as 0.64. Specifically the CS5 type specimen which has a ratio of one-fourth (= width/length) was revealed as an appropriate shape of specimen to show those elastic behavior.

scholarly journals A PRODUCT DEVELOPMENT APPROACH TO TEACHING INTRODUCTORY ENGINEERING DESIGN

2011 ◽  
Author(s):  
L. M. Lye ◽  
A. D. Fisher
Keyword(s):  
Engineering Design ◽  
Just In Time ◽  
First Year ◽  
Design Problems ◽  
New Approach ◽  
Approach To Teaching ◽  
Development Approach ◽  
Business Engineering ◽  
Realization Process ◽  
Product Realization

This paper describes a new approach to teaching first year design at Memorial University. Students are introduced to engineering design using the product realization process (PRP) as a platform. The course integrates the business, engineering design, and prototyping functions of the PRP. The just-in-time structured delivery of background tools and theory complement the relatively unstructured nature of the design problems. Lab exercises are used to intoduce the basic practicalities of mechanical, electrical and electronic design. Projects are completed in teams with emphasis placed on teamwork, project management and communication skills. Student enthusiasm has been very high and this aides significantly in the learning process.

Self-Loosening Mechanism of Nuts Due to Lateral Motion of Fastened Plate

2007 ◽  
Author(s):  
Yasumasa Shoji ◽  
Toshiyuki Sawa ◽  
Hiroshi Yamanaka
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bolted Joints ◽  
Lateral Motion ◽  
Element Analysis ◽  
New Approach ◽  
The Finite Element Analysis ◽  
Mechanical Element ◽  
Vibration Tests

As self-loosening of nuts is really a problem for bolted joints in practical use, countermeasures for the loosening is highly required. In this situation non-loosening fasteners are one of the resolutions for any fastened machinery as an essential mechanical element. Self-loosening of threaded bolt/nut systems has been researched in number of works and most researches were based on experiment and a few were based on the finite element analysis in these years. Using this new approach, various types of nuts can also be examined. Among these nuts eccentric nuts and slit nuts are especially expected to be the solution, as these nuts are reported to endure NAS vibration tests and were not loosened. In the authors’ previous paper, an eccentric nut and a normal nut were analyzed and compared in the aspect of loosening property. In this paper degree of loosening of various nuts was investigated by experiment and the FEA.

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.

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