Three-Dimensional Steady Flow in Non-Linear Elastic Collapsible Tubes

2009 ◽  
Author(s):  
Wonhyuk Koh ◽  
Sungwoo Kang ◽  
Myunghwan Cho ◽  
Jung Yul Yoo
Keyword(s):  
Steady Flow ◽  
Elastic Material ◽  
Three Dimensional ◽  
Elastic Tube ◽  
Wall Material ◽  
Linear Elastic Material ◽  
Linear Elastic ◽  
Collapsible Tubes ◽  
Elastic Wall ◽  
Non Linear

Three-dimensional fluid-structure interaction problem arising from steady flow in non-linear elastic tube is studied numerically by using a finite element software, ADINA. Strain-energy density function is used for non-linear elastic analysis of solid material. Navier-Stokes equation coupled with elastic wall condition is solved for the fluid flow. To simulate interactions between the fluid and the solid domains, arbitrary Lagrangian-Eulerian (ALE) formulation is utilized. For validation, thin-walled linear elastic collapsible tubes is computed and compared with previous numerical results. The tube collapses into the buckling mode N = 2 and the results are in excellent agreement with a previous study. Then, the results for linear elastic tube are compared with those for non-linear elastic tube to show the effects of non-linear elasticity of the wall. The wall material is considered to be non-linear hyperelastic and isotropic. The non-linear elastic wall shows the tendency to preserve its shape more than the linear material. The deformation patterns, pressure distributions of the tube with non-linear elastic material are significantly different from those with linear elastic material.

An optimized cross-linked network model to simulate the linear elastic material response of a smart polymer

2015 ◽  
Vol 27 (11) ◽  
pp. 1461-1475 ◽  
Author(s):  
Jinjun Zhang ◽  
Bonsung Koo ◽  
Nithya Subramanian ◽  
Yingtao Liu ◽  
Aditi Chattopadhyay
Keyword(s):  
Network Model ◽  
Elastic Material ◽  
Smart Polymer ◽  
Material Response ◽  
Linear Elastic Material ◽  
Linear Elastic

Simulation of Fatigue Crack Growth Using XFEM

2020 ◽  
Author(s):  
Durlabh Bartaula ◽  
Yong Li ◽  
Smitha Koduru ◽  
Samer Adeeb
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Elastic Material ◽  
Low Cycle Fatigue ◽  
Material Behavior ◽  
Plastic Behavior ◽  
Linear Elastic Material ◽  
Linear Elastic ◽  
Cyclic Approach

Abstract Pipelines carrying oil and gas are susceptible to fatigue failure (i.e., unstable fatigue crack propagation) due to fluctuating loading such as varying internal pressure and other external loadings. Fatigue crack growth (FCG) prediction through full-scale pipe tests can be expensive and time consuming, and experimental data is limited particularly in the face of large uncertainty involved. In contrast, numerical simulation techniques (e.g., XFEM) can be alternative to study the FCG, given that numerical models can be theoretically and/or experimentally validated with reasonable accuracy. In this study, capabilities and limitations of existing fatigue analysis code (e.g., direct cyclic approach with XFEM) in Abaqus for low cycle fatigue simulation are explored for compact-tension (CT) specimens and pipelines assuming linear elastic material behavior. The simulated FCG curve for a CT specimen is compared with that obtained from the analytical method using the stress intensity factor prescribed in ASTM E647. However, for real pipelines with elastic-plastic behavior, direct cyclic approach is not suitable, and an indirect cyclic approach is used based on the fracture energy parameters (e.g., J integral) calculated using XFEM in Abaqus. FCG law (e.g., power law relationship like Paris law) is used to generate the fatigue crack growth curve. For comparison, the FCG curve obtained through direct cyclic approach for pipelines assuming linear elastic material is also presented. The comparative studies here indicate that XFEM-based FCG simulation using appropriate techniques can be applied to pipelines for fatigue life prediction.

scholarly journals Assessment of Progressive Collapse Resistance of Steel Structures with Moment Resisting Frames

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
Osama Mohamed ◽  
Rania Khattab
Keyword(s):  
Progressive Collapse ◽  
Three Dimensional ◽  
The United States ◽  
Dimensional System ◽  
Structural System ◽  
Linear Elastic ◽  
Load Carrying ◽  
Non Linear ◽  
Moment Resisting ◽  
Primary Load

This paper evaluates the practice of using moment connections in the perimeter of the structural system and shear connections within the interior connections of the three-dimensional structural system from the perspective of resistance to progressive collapse. The enhanced resistance to progressive collapse associated with using moment resisting connections at the perimeter as well as internal to the three-dimensional system is assessed. Progressive collapse occurrence and system resistance are determined using the alternate path method which presumes a primary load carrying-member is notionally removed. The paper compares the structural response determined using linear elastic, non-linear elastic and non-linear dynamic analyses. Linear and non-linear static analyses are found to be incapable of capturing the response pursuant to the loss of the primary load carrying member. The analysis procedures used in this study followed (for the most part) the United States Department of Defense Guide for Progressive Collapse Resistant Design of Structures.

Effect of Housing Support on Bearing Dynamics

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Lijun Cao ◽  
Matthew D. Brouwer ◽  
Farshid Sadeghi ◽  
Lars-Erik Stacke
Keyword(s):  
Finite Element ◽  
Elastic Material ◽  
Contact Forces ◽  
Support Structure ◽  
Linear Elastic Material ◽  
Outer Race ◽  
Linear Elastic ◽  
Elastomeric Material ◽  
Bearing Dynamics ◽  
Element Method

The objective of this investigation was to determine the effect of housing support on bearing performance and dynamics. In order to achieve the objective, an existing dynamic bearing model (DBM) was coupled with flexible housing model to include the effect of support structure on bearing dynamics and performance. The DBM is based on the discrete element method, in which the bearing components are assumed to be rigid. To achieve the coupling, a novel algorithm was developed to detect contact conditions between the housing support and bearing outer race and then calculate contact forces based on the penalty method. It should be noted that although commercial finite element (FE) software such as abaqus is available to model flexible housings, combining these codes with a bearing model is quite difficult since the data transfer between the two model packages is time-consuming. So, a three-dimensional (3D) explicit finite element method (EFEM) was developed to model the bearing support structure for both linear elastic and nonlinear inelastic elastomeric materials. The constitutive relationship for elastomeric material is based on an eight chain model, which captures hyperelastic behavior of rubber for large strains. The viscoelastic property is modeled by using the generalized Maxwell-element rheological model to exhibit rate-dependent behaviors, such as creep and hysteresis on cyclic loading. The results of this investigation illustrate that elastomeric material as expected has large damping to reduce vibration and absorb energy, which leads to a reduction in ball–race contact forces and friction. A parametric study confirmed that the viscoelastic stress (VS) contributes significantly to the performance of the material, and without proper amount of viscoelasticity it loses its advantage in vibration reduction and exhibits linear elastic material characteristics. As expected, it is also demonstrated that housing supports made of linear elastic material provide minimal damping and rely on the bearing friction to dissipate energy. A study of housing support geometry demonstrates that bearing support plays a large role on the dynamic performance of the bearing. Motion of bearing outer race is closely related to the geometry and symmetry of the housing.

Sign in / Sign up

Export Citation Format

Share Document