A Finite Element Model for Cables With Nonsymmetrical Geometry and Loads

1994 ◽  
Vol 116 (1) ◽  
pp. 14-20 ◽  
Author(s):  
T. T. Le ◽  
R. H. Knapp
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cross Section ◽  
Cross Sections ◽  
Degrees Of Freedom ◽  
Circular Cross Section ◽  
Element Model ◽  
Computer Code ◽  
Deformation Analysis ◽  
Contact Points

A new two-dimensional finite element model is proposed for the deformation analysis of cable cross sections. The deformations of the cable cross section are of considerable design interest because of their effect on the induced torque or rotation of the cable. This model accounts for material orthotropy and nonsymmetrical geometry and loads. Each component of the cable is assumed to possess a circular cross section and is modeled as a macro-element having nodal degrees-of-freedom at all contact points with adjoining components. Usual finite element procedures are applied to solve for the unknown displacements at contact nodal points. The model is implemented in a computer code and is verified by test results obtained for an as-built cable.

Support-Condition Analyses of Rotating Beams Under Distributed Imbalance Loading

2011 ◽  
Author(s):  
Kai Jokinen ◽  
Erno Keskinen ◽  
Marko Jorkama ◽  
Wolfgang Seemann
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cross Section ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Constant Cross Section ◽  
Support Condition ◽  
Beam Elements

In roll balancing the behaviour of the roll can be studied either experimentally with trial weights or, if the roll dimensions are known, analytically by forming a model of the roll to solve response to imbalance. Essential focus in roll balancing is to find the correct amount and placing for the balancing mass or masses. If this selection is done analytically the roll model used in calculations has significant effect to the balancing result. In this paper three different analytic methods are compared. In first method the mode shapes of the roll are defined piece wisely. The roll is divided in to five parts having different cross sections, two shafts, two roll ends and a shell tube of the roll. Two boundary conditions are found for both supports of the roll and four combining equations are written to the interfaces of different roll parts. Totally 20 equations are established to solve the natural frequencies and to form the mode shapes of the non-uniform roll. In second model the flexibility of shafts and the stiffness of the roll ends are added to the support stiffness as serial springs and the roll is modelled as a one flexibly supported beam having constant cross section. Finally the responses to imbalance of previous models are compared to finite element model using beam elements. Benefits and limitations of each three model are then discussed.

Separable Polyurethane Solid Tires for a Folding Bike

2011 ◽  
Author(s):  
Sarom Ryu ◽  
Jaehyung Ju ◽  
Doo-Man Kim ◽  
Hyeonu Heo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Contact Pressure ◽  
Cross Section ◽  
Cross Sections ◽  
Element Model ◽  
Energy Depletion ◽  
Vertical Stiffness ◽  
Load Carrying ◽  
Lower Contact

With increasing awareness of energy depletion and environmental pollution, bikes have been paid more attention as an important transportation tool. Folding or separable part design of a bike may increase a use of bikes due to its portable capability. In this study, we suggest a novel separable solid bike tire for a folding bike use. Finite element model with ABAQUS is used to model a polyurethane (PU) separable solid tire. Vertical stiffness and contact pressure are compared with those of a conventional pneumatic bike tire. Elliptical hollow cross-sections of a PU solid tire are investigated to match a vertical stiffness and contact pressure of a conventional pneumatic bike tire. The suggested PU solid tire with an elliptical hollow cross-section shows a lower contact pressure than a pneumatic bike tire when they are designed to be the same load carrying capability.

Finite Element Model of the Human Knee Joint to Study Tibio-Femoral Contact Mechanics

2000 ◽  
Author(s):  
Tammy Haut Donahue ◽  
Maury L. Hull ◽  
Mark M. Rashid ◽  
Christopher R. Jacobs
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Degrees Of Freedom ◽  
Soft Tissues ◽  
Element Model ◽  
Human Knee ◽  
Human Knee Joint ◽  
Solid Models ◽  
Flexion Extension ◽  
A New Technique

Abstract A finite element model of the tibio-femoral joint in the human knee was created using a new technique for developing accurate solid models of soft tissues (i.e. cartilage and menisci). The model was used to demonstrate that constraining rotational degrees of freedom other than flexion/extension when the joint is loaded in compression markedly affects the load distribution between the medial and lateral sides of the joint. The model also was used to validate the assumption that the bones can be treated as rigid.

scholarly journals Membrane analogy for multi-material bars under torsion

2019 ◽  
Vol 475 (2225) ◽  
pp. 20190124 ◽  
Author(s):  
Laura Galuppi ◽  
Gianni Royer-Carfagni
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Cross Sections ◽  
Three Dimensional ◽  
Element Model ◽  
Elastic Problem ◽  
Two Dimensional ◽  
Torsion Problem ◽  
Linear Elastic ◽  
Physical Apparatus

Prandtl's membrane analogy for the torsion problem of prismatic homogeneous bars is extended to multi-material cross sections. The linear elastic problem is governed by the same equations describing the deformation of an inflated membrane, differently tensioned in regions that correspond to the domains hosting different materials in the bar cross section, in a way proportional to the inverse of the material shear modulus. Multi-connected cross sections correspond to materials with vanishing stiffness inside the holes, implying infinite tension in the corresponding portions of the membrane. To define the interface constrains that allow to apply such a state of prestress to the membrane, a physical apparatus is proposed, which can be numerically modelled with a two-dimensional mesh implementable in commercial finite-element model codes. This approach presents noteworthy advantages with respect to the three-dimensional modelling of the twisted bar.

Residual stress distribution in built-in beams

2020 ◽  
pp. 146442072095861
Author(s):  
FA de Castro ◽  
Paulo P Kenedi ◽  
LL Vignoli ◽  
I I T Riagusoff
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Element Model ◽  
Residual Stress Distribution ◽  
Concentrated Load ◽  
Load Growth ◽  
Final Failure

Metallic hyperstatic structures, like beams, submitted to excessive loads, do not fail completely before fully yielding in more than one cross section. Indeed, for built-in beams, three cross sections must be fully yielded before the final failure can occur. So, modeling the evolution of the cross-section residual stress distribution is an important subject that should be addressed to guarantee the stress analysis modeling correctness. This paper analyses the residual stress distribution evolution, in critical cross sections, of built-in beams during a transversal concentrated load growth, until the final failure through hinges formation. A finite element model is also presented. The results show good matches with the numerical model, used as a reference.

Modeling of fast pre-joining processes optimization for skin-stringer panels

2014 ◽  
Vol 34 (4) ◽  
pp. 323-332 ◽  
Author(s):  
Gang Liu ◽  
Wei Tang ◽  
Ying-Lin Ke ◽  
Qing-Liang Chen ◽  
Yunbo Bi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Degrees Of Freedom ◽  
Traditional Approach ◽  
Element Model ◽  
Optimal Number ◽  
Neighborhood Search ◽  
Adaptive Genetic Algorithm ◽  
Time Saving ◽  
Content Type

Purpose – The purpose of this paper is to propose a new model for optimizing pre-joining processes quickly and accurately, guiding workers to standardized operations. For the automatic riveting in panel assemblies, the traditional approach of determination of pre-joining processes entirely rests on the experience of workers, which leads to the improper number, location and sequence of pre-joining, the low quality stability and the high repair rate in most cases. Design/methodology/approach – The clearances computation with the complete finite element model for every process combination is time-consuming. Therefore a fast pre-joining processes optimization model (FPPOM) is proposed. This model treats both the measured initial clearances and the stiffness matrices of key points of panels as an input; considers the permissive clearances as an evaluation criterion; regards the optimal number, location and sequence as an objective; and takes the neighborhood-search-based adaptive genetic algorithm as a solution. Findings – A comparison between the FPPOM and complete finite element model with clearances (CFEMC) was made in practice. Further, the results indicate that running the FPPOM is time-saving by >90 per cent compared with the CFEMC. Practical implications – This paper provides practical insights into realizing the pre-joining processes optimization quickly. Originality/value – This paper is the first to propose the FPPOM, which could simplify the processes, reduce the degrees of freedom of nodes and conduct the manufacturers to standardized manipulations.

Verification of Predicted Knee Replacement Kinematics During Simulated Gait in the Kansas Knee Simulator

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Jason P. Halloran ◽  
Chadd W. Clary ◽  
Lorin P. Maletsky ◽  
Mark Taylor ◽  
Anthony J. Petrella ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Knee Replacement ◽  
Degrees Of Freedom ◽  
Computational Models ◽  
Evaluation Process ◽  
Element Model ◽  
Explicit Finite Element ◽  
Knee Simulator ◽  
Flexion Extension

Evaluating total knee replacement kinematics and contact pressure distributions is an important element of preclinical assessment of implant designs. Although physical testing is essential in the evaluation process, validated computational models can augment these experiments and efficiently evaluate perturbations of the design or surgical variables. The objective of the present study was to perform an initial kinematic verification of a dynamic finite element model of the Kansas knee simulator by comparing predicted tibio- and patellofemoral kinematics with experimental measurements during force-controlled gait simulation. A current semiconstrained, cruciate-retaining, fixed-bearing implant mounted in aluminum fixtures was utilized. An explicit finite element model of the simulator was developed from measured physical properties of the machine, and loading conditions were created from the measured experimental feedback data. The explicit finite element model allows both rigid body and fully deformable solutions to be chosen based on the application of interest. Six degrees-of-freedom kinematics were compared for both tibio- and patellofemoral joints during gait loading, with an average root mean square (rms) translational error of 1.1 mm and rotational rms error of 1.3 deg. Model sensitivity to interface friction and damping present in the experimental joints was also evaluated and served as a secondary goal of this paper. Modifying the metal-polyethylene coefficient of friction from 0.1 to 0.01 varied the patellar flexion-extension and tibiofemoral anterior-posterior predictions by 7 deg and 2 mm, respectively, while other kinematic outputs were largely insensitive.

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