Finite Element Modeling and Analysis of Structural Joints Using Nuts and Bolts

2011 ◽  
Author(s):  
Prasannakumar S. Bhonge ◽  
Brian D. Foster ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Modeling ◽  
Joint Modeling ◽  
3D Models ◽  
Element Mesh ◽  
Static Tests ◽  
Modeling And Analysis ◽  
Element Modeling ◽  
Double Shear

The majority of the structural failures of mechanical structures and systems are found in joints rather than continuous material. Joints have historically consisted of assemblies involving nuts, bolts, screws, etc. and the design and analysis of these joints can be quite challenging. This work provides two baselines on the finite element modeling (FEM) methods and analysis of a nut and bolt joint. The first baseline involves a basic modeling method using linear calculation of 2D plates and bar elements, and the second baseline involves one of the more complex methods using non-linear calculation of 3D solids. The two methods are described for modeling of a joint for two test conditions, namely the double shear joint in tension with two different bolt sizes and two plate thicknesses. First, the simplified method of rigid elements and equivalent strength beam elements is considered. This technique lacks the simulation of bearing stresses, stress concentration at the bolt hole location, and bending stiffness of the bolt. The second method, uses 3D models that provides the actual nut and bolt surfaces, bearing stresses are introduced in the joint modeling. Classical hand calculations are carried out on the static tests and compared with the FEM results. Additionally, the effects of element mesh refinement on the nut and bolt contact surfaces, and types of contacts are analyzed for the 3D models. A parametric study is carried out on the stresses developed and stress concentration factors.

A Meta-Object Based Approach to Finite Element Modeling

2001 ◽  
Author(s):  
Santosh Shanbhag ◽  
Ian R. Grosse ◽  
Jack C. Wileden ◽  
Alan Kaplan
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Production Model ◽  
Engineering Analysis ◽  
Demand Model ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Element Modeling ◽  
Molded Part ◽  
Analysis Models

Abstract With the integration of CAD and FEA software packages, design engineers who are not skilled in finite element analysis are performing finite element modeling and analysis. Furthermore, in the analysis of a system, engineers often make numerous modeling simplifications and analysis assumptions depending on the trade-off between cost, accuracy, precision or other engineering analysis objectives. Thus, reusability or interoperability of engineering analysis models is difficult and often impractical due to the wealth of knowledge involved in the creation of such models and the lack of formal methods to codify and explicitly represent this critical modeling knowledge. Most institutions and organizations have started documenting these simplifications and assumptions, making them understandable for the other engineers within the organization. However, this does not allow a seamless exchange of data or interoperability with other analysis models of similar or dissimilar nature. This plays a very important role in today’s market, which is moving away from the traditional make-to-stock production model to a build-to-demand model. We address these issues in this paper by adopting and extending the computer science concept of meta-object, and applying it in novel ways to the domain of FEA and the representation of finite element modeling knowledge. We present a taxonomy for engineering models that aids in the definition of the various object analysis classes. A simple beam analysis example, followed by a more realistic injection-molded part example. The latter example involves injection-mold filling simulation, thermal cooling, and part ejection analyses which are subclasses for a generic manufacturing analysis meta-object class. Prototype implementations of automated support for this meta-object approach to finite element modeling is in progress.

Finite Element Modeling and Analysis of Human Pelvis

2007 ◽  
Author(s):  
A. Ivanov ◽  
A. Kiapour ◽  
N. Ebraheim ◽  
V. K. Goel
Keyword(s):  
Finite Element ◽  
Individual Differences ◽  
Finite Element Modeling ◽  
Complex Geometry ◽  
Biomechanical Properties ◽  
Component Structure ◽  
Modeling And Analysis ◽  
Element Modeling ◽  
Biomechanical Behavior

The pelvis is a multi-component structure with complex geometry and biomechanical properties. Complex geometry, individual differences between subcomponents and aging create difficulties in analyzing the biomechanical behavior of the pelvis.

Pressure-Containing Sleeve Alternatives

2006 ◽  
Author(s):  
Robert B. Lazor ◽  
Brock Bolton ◽  
Julian Florez ◽  
Carlos Nieves
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Finite Element Modeling ◽  
Operating Pressure ◽  
Element Modeling ◽  
Expected Performance ◽  
Contour Plots ◽  
Steel Grades ◽  
Different Thickness

The work described in this paper was completed to assess the expected performance of various repair sleeve configurations on an NPS 30, Grade X70 pipeline. A total of ten sleeve variations were studied, and these included sleeve-on-pipe, sleeve-over-collar, and sleeve-over-double collar configurations. The comparisons were based on the stress results of axisymmetric finite element modeling of the sleeve geometries, and included examining sleeves with different thickness, models with and without a gap between the sleeve and the pipe, and cases in which the annulus between the sleeves and pipe were either pressurized or not pressurized. Complementary tasks involved with this work included the specification of recommended epoxy materials and steel grades for reinforcing sleeves. The results of the analyses are presented in terms of contour plots of stress at the maximum operating pressure of the pipe, showing the general stress distribution and indicating areas of stress concentration. This study demonstrates how the loads vary amongst the different sleeve types, and shows how variations in geometry and loading conditions between models affect the operating stresses.

Sign in / Sign up

Export Citation Format

Share Document