Nonlinear Finite Element Analysis of Radial Lip Seals

2017 ◽  
Author(s):  
Rutuja Suhas Joshi ◽  
David C. Roberts ◽  
Hany Ghoneim
Keyword(s):  
Finite Element ◽  
Numerical Results ◽  
Material Behavior ◽  
Contact Load ◽  
Nonlinear Material ◽  
Rotating Shaft ◽  
Element Analysis ◽  
Lip Seal ◽  
Contact Width ◽  
Lip Seals

Oil seals or radial lip seals are widely used in reciprocating, oscillating and rotating shaft applications. The sealability and durability of a lip seal greatly depends on the contact load and contact pressure distribution. It is challenging to find these contact parameters of the seal due to non-linear material behavior and small contact width, therefore numerical simulation can prove to be a viable method. In this paper, to address these challenges and to develop a robust numerical methodology, a Finite Element Model of a lip seal is created in ANSYS APDL. This model includes contact elements to model the lip seal’s contact-fit with certain interference, nonlinear material properties of elastomer and effect of the finger spring molded in the rubber body of the seal. The parameters for two term Mooney Rivlin Model for elastomer are obtained from simple uniaxial tension test. The numerical results demonstrate that the contact load exerted by the composite seal (with spring) is higher than the contact load exerted by elastomer portion of seal alone. It can be implied that the spring augments the radial load and increases the stiffness of the lip, which improves the lip’s sealability and durability. Experimental study is carried to validate the numerical results. The experimental results correspond well with the numerical results.

Finite Element Analysis on Nitinol Medical Applications

2002 ◽  
Author(s):  
Xiao-Yan Gong ◽  
Alan R. Pelton
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Element Analysis ◽  
Highly Nonlinear ◽  
Device Applications ◽  
Specific Material

Nitinol, an alloy of about 50% Ni and 50% Ti, is a very unique material. At constant temperature above its Austenite finish (Af) temperature, under uniaxial tensile test, the material is highly nonlinear and capable of large deformation to the ultimate strain on the order of 15%. This material behavior, known as superelasticity, along with its excellent biocompatibility and corrosion resistance, makes Nitinol a perfect material candidate for many medical device applications. However, the nonlinear material response also requires a specific material description to perform the stress analysis. The user developed material subroutine from HKS/West makes the simulation of the Nitinol devices possible. This article presents two case studies of the nonlinear finite element analysis using ABAQUS/Standard and the Nitinol UMAT.

Strength Assessment of a Pressurized Thick-Walled Cylinder Using Structural-Thermal Coupled Finite Element Analysis

2007 ◽  
Author(s):  
John Feldhacker ◽  
Zhong Hu ◽  
Fereidoon Delfanian
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Damage ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Thick Wall ◽  
Firing Process ◽  
Surface Erosion ◽  
Element Analysis ◽  
Strength Assessment

Upon analysis, thick wall cylinders designed for use in cannon barrel applications experience thermal and mechanical loading very near their fatigue limit. Chief factors in determining the lifetime of a cannon barrel involve internal thermal and mechanical damage caused by projectile firing. The most significant damage experienced in the cannon barrel is surface crack propagation which aids in surface erosion and fatigue failure. Adequate knowledge of these failure phenomena and the ability to predict the lifetime of gun barrels will greatly increase the successful application of their designs. This study will investigate three-dimensional stress of a pressurized thick cylinder using computer simulation based on structural-thermal coupled finite element analysis. The effects of high temperature and high pressure, as well as nonlinear material behavior, on stress-strain distribution during the firing process will be evaluated. This computer-based stress analysis will prove to be a valuable tool for assessing strength and forecasting the lifetime of cannon barrels.

Case Studies on the Use of Thermal-Mechanical Finite Element Analysis to Evaluate Weld Ring Gasket and Diaphragm Seal Designs

2018 ◽  
Author(s):  
Phillip E. Prueter ◽  
Robert C. Davis ◽  
Clay D. Rodery ◽  
Stephen F. McJones ◽  
Richard P. Brodzinski ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Heat Exchanger ◽  
Design Feature ◽  
Valuable Insight ◽  
Element Analysis ◽  
Lip Seal ◽  
Seal Design ◽  
Lip Seals ◽  
Damage Tolerant

Weld ring type gaskets are relatively common in the refining and petrochemical industries. These gasket configurations usually consist of two steel rings, fillet-welded to each of the mating flanges with another seal weld between the lips of the two rings. These seal welds or lip seals are sometimes prone to in-service cracking that can eventually lead to leakage and costly equipment downtime. One particular design feature that can significantly influence the propensity for leakage is the shape of the weld rings; flat-lip weld rings or hollow-lip (Omega-seal) weld rings are the two most commonly used designs. The hollow-lip designs inherently offer more flexibility and can generally accommodate more differential radial thermal expansion between mating flanges. This paper highlights a case study of a high-pressure heat exchanger where the shell side-to-tube side girth flange joint is fitted with a weld ring gasket configuration. Comparisons are made using detailed finite element analysis (FEA) that include bolt pretension and pressure-temperature loading. Sensitivity to lip seal design, temperature profile, and assumed friction coefficient between seating surfaces is also investigated. Furthermore, general commentary on flat and hollow lip weld ring gasket geometries is provided with design recommendations for different applications. In summary, the flat-lip seal weld experiences high shear stress, even with small amounts of differential temperature between flanges, which makes it prone to cracking. The added compliance of the hollow-lip seal design can minimize stresses in the seal weld, but understanding operating temperature differentials between mating flanges represents a key aspect of ensuring leak-free operation. The design of a diaphragm seal on a flat heat exchanger channel cover is also evaluated using FEA techniques, with sensitivity analysis on the size of the external fillet weld and diaphragm material specification. The analysis techniques presented in this paper offer valuable insight into establishing damage tolerant weld ring gasket and diaphragm seal designs to minimize the potential for leakage and to optimize critical gasket and bolting parameters.

Dynamic Viscoelastic Incremental-Layerwise Finite Element Method for Multilayered Structure Analysis Based on the Relaxation Approach

2014 ◽  
Vol 30 (6) ◽  
pp. 593-602 ◽  
Author(s):  
M. Malakouti ◽  
M. Ameri ◽  
P. Malekzadeh
Keyword(s):  
Finite Element ◽  
Viscoelastic Material ◽  
Constitutive Relations ◽  
Computer Code ◽  
Multilayered Structure ◽  
Numerical Results ◽  
Material Behavior ◽  
Element Formulation ◽  
Element Analysis ◽  
Laminated Structures

AbstractThis paper presents an axisymmetric layerwise finite element formulation for dynamic analysis of laminated structures with embedded viscoelastic material whose constitutive behavior is represented by the Prony-generalized Maxwell series. To account the time dependence of the constitutive relations of linear viscoelastic materials, the incremental formulation in the temporal domain is used. Layerwise finite element has been shown to provide an efficient and accurate tool for the simulation of laminated structure. Most of the previous work on numerical simulation of laminated structures has been limited to elastic material behavior. Thus, the current work focuses on layerwise finite element analysis of laminated structures with embedded viscoelastic material. A computer code based on the presented formulation has been developed to provide the numerical results. The present approach is verified by studying its convergence behavior and comparing the numerical results with those obtained using the ABAQUS software. Finally, and as an application of the presented formulation, the effects of load duration on the dynamic structural responses of multilayered pavements are studied.

scholarly journals Finite Element Software for Rubber Products Design

2018 ◽  
Vol 3 (1) ◽  
pp. 13-20
Author(s):  
Dávid Huri
Keyword(s):  
Finite Element ◽  
Complex Analysis ◽  
Large Deformations ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Material Models ◽  
Finite Element Software ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Different Types

Automotive rubber products are subjected to large deformations during working conditions, they often contact with other parts and they show highly nonlinear material behavior. Using finite element software for complex analysis of rubber parts can be a good way, although it has to contain special modules. Different types of rubber materials require the curve fitting possibility and the wide range choice of the material models. It is also important to be able to describe the viscoelastic property and the hysteresis. The remeshing possibility can be a useful tool for large deformation and the working circumstances require the contact and self contact ability as well. This article compares some types of the finite element software available on the market based on the above mentioned features.

Finite Element Analysis of Casing Material Behavior in Steam Injection Well Operations

2015 ◽  
Vol 799-800 ◽  
pp. 196-200
Author(s):  
Abhilash M. Bharadwaj ◽  
Sonny Irawan ◽  
Saravanan Karuppanan ◽  
Mohamad Zaki bin Abdullah ◽  
Ismail bin Mohd Saaid
Keyword(s):  
Finite Element ◽  
Oil Recovery ◽  
Thermal Stresses ◽  
Oil And Gas ◽  
Extreme Temperature ◽  
Injection Pressure ◽  
Oil And Gas Industry ◽  
Steam Injection ◽  
Material Behavior ◽  
Element Analysis

Casing design is one of the most important parts of the well planning in the oil and gas industry. Various factors affecting the casing material needs to be considered by the drilling engineers. Wells partaking in thermal oil recovery processes undergo extreme temperature variation and this induces high thermal stresses in the casings. Therefore, forecasting the material behavior and checking for failure mechanisms becomes highly important. This paper uses Finite Element Methods to analyze the behavior two of the frequently used materials for casing - J55 and L80 steels. Modeling the casing and application of boundary conditions are performed through Ansys Workbench. Effect of steam injection pressure and temperature on the materials is presented in this work, indicating the possibilities of failure during heating cycle. The change in diameter of the casing body due to axial restriction is also presented. This paper aims to draw special attention towards the casing design in high temperature conditions of the well.

Finite Element Analysis of the Effect of Surface Hardening Depth in Port Crane Wheel

2011 ◽  
Vol 291-294 ◽  
pp. 3282-3286 ◽  
Author(s):  
Jiang Wei Wu ◽  
Peng Wang
Keyword(s):  
Finite Element ◽  
Surface Hardening ◽  
Three Dimensional ◽  
Element Model ◽  
Contact Stresses ◽  
Numerical Results ◽  
Element Analysis ◽  
Finite Element Software ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In port crane industry, the surface hardening technique is widely used in order to improve the strength of wheel. But the hardening depth is chosen only by according to the experience, and the effect of different hardened depths is not studied theoretically. In this paper, the contact stresses in wheel with different hardening depth have been analyzed by applying three-dimensional finite element model. Based on this model, the ANSYS10.0 finite element software is used. The elastic wheel is used to verify the numerical results with the Hertz’s theory. Three different hardening depths, namely 10mm, 25mm and whole hardened wheel, under three different vertical loads were applied. The effect of hardening depth of a surface hardened wheel is discussed by comparing the contact stresses and contact areas from the numerical results.

Creep Life Simulation and Assessment of High Temperature Piping Systems and Components

2012 ◽  
Author(s):  
Brian Rose ◽  
James Widrig
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Creep Behavior ◽  
Material Behavior ◽  
Piping System ◽  
Remaining Life ◽  
Creep Life ◽  
Element Analysis ◽  
Piping Systems

High temperature piping systems and associated components, elbows and bellows in particular, are vulnerable to damage from creep. The creep behavior of the system is simulated using finite element analysis (FEA). Material behavior and damage is characterized using the MPC Omega law, which captures creep embrittlement. Elbow elements provide rapid yet accurate modeling of pinching of piping, which consumes a major portion of the creep life. The simulation is used to estimate the remaining life of the piping system, evaluate the adequacy of existing bellows and spring can supports and explore remediation options.

Dynamic Behaviour and Crack Detection of a Multi Cracked Rotating Shaft using Adaptive Neuro-Fuzzy-Inference System

2016 ◽  
Vol 6 (4) ◽  
pp. 1-10 ◽  
Author(s):  
Rajeev Ranjan
Keyword(s):  
Finite Element ◽  
Fuzzy Inference System ◽  
Crack Detection ◽  
Fuzzy Inference ◽  
Crack Depth ◽  
Multiple Cracks ◽  
Rotating Shaft ◽  
Element Analysis ◽  
Inference System ◽  
Neuro Fuzzy

The presence of crack changes the physical characteristics of a structure which in turn alter its dynamic response characteristics. So it is important to understand dynamics of cracked structures. Crack depth and location are the main parameters influencing the vibration characteristics of the rotating shaft. In the present study, a technique based on the measurement of change of natural frequencies has been employed to detect the multiple cracks in rotating shaft. The model of shaft was generated using Finite Element Method. In Finite Element Analysis, the natural frequency of the shaft was calculated by modal analysis using the software ANSYS. The Numerical data were obtained from FEA, then used to train through Adaptive Neuro-Fuzzy-Inference System. Then simulations were carried out to test the performance and accuracy of the trained networks. The simulation results show that the proposed ANFIS estimate the locations and depth of cracks precisely.

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