Numerical Modeling of Air Cushion Vehicle Flexible Fingers

2015 ◽  
Author(s):  
Robert E. Cole ◽  
Wayne L. Neu
Keyword(s):  
Research Effort ◽  
Prior Work ◽  
Fluid Structure Interactions ◽  
Elastic Materials ◽  
Material Models ◽  
Computational Tools ◽  
Linear Elastic ◽  
Hyper Elastic ◽  
Air Cushion ◽  
Air Cushion Vehicle

The goal of this research is to numerically model flexible finger seals of an air cushion vehicle (ACV) to more accurately predict resistance for these craft. Advancements in computational tools for fluid-structure interactions have set the stage for this effort. Prior work for this application has focused on planer type seals and not the finger type seals typical of modern ACVs. While this research effort remains underway and limited results are available, it is the authors’ desire to propose a pathway forward. Following the motivation and a brief review of prior work, verification of Abaqus/Explicit’s fluid solver is conducted using the analytical solution to Couette flow. Next, Abaqus/Standard (implicit scheme) is used to verify the finite element options for the structural portion. Various hyper elastic material models are also compared. Lastly, a FSI validation problem is conducted using Abaqus/Explicit for both linear elastic and hyper elastic materials.

scholarly journals MODELLING AND SIMULATION OF LATTICE STRUCTURES USING VARIOUS MATERIAL MODELS FOR POLYMERIC MATERIALS

2018 ◽  
Vol 18 ◽  
pp. 48
Author(s):  
Kerstin Lehner ◽  
Anna Kalteis ◽  
Zoltan Major
Keyword(s):  
Lightweight Design ◽  
Linear Thermal Expansion ◽  
Polymeric Materials ◽  
Mechanical Analysis ◽  
Elastic Behaviour ◽  
Material Models ◽  
Linear Elastic ◽  
Applied Loading ◽  
Hyper Elastic ◽  
Linear Elastic Behaviour

Based on lightweight design concepts, lattices are increasingly considered as internal structures. This work deals with the simulation of periodically constructed lattices to characterize their behaviour under different loadings considering various material models. A thermo-mechanical analysis was done, which is resulting in negative CLTE-values (Coefficient of Linear Thermal Expansion). Simulations with linear-elastic behaviour were evaluated regarding the tensile, compression and shear modulus and the Poisson’s ratio. Some of the investigated structures behave auxetic. Beside the linear elastic behaviour, also the hyper-elastic and visco-elastic behaviour of some structures were investigated. Furthermore, elasto-plastic simulations were performed where the applied loading was biaxial. As a result the initial yield surfaces were presented. The individual RVEs (Representative Volume Elements) can be utilized for different areas of application dependent on the used materials.

A Soft Bending-type Actuator using Hyper-elastic Materials

2019 ◽  
Author(s):  
Debadrata Sarkar ◽  
Shounak Dasgupta ◽  
Srinivasa Reddy N. ◽  
Aman Arora ◽  
Soumen Sen
Keyword(s):  
Elastic Materials ◽  
Hyper Elastic

scholarly journals Variation of Passive Biomechanical Properties of the Small Intestine along Its Length: Microstructure-Based Characterization

2021 ◽  
Vol 8 (3) ◽  
pp. 32
Author(s):  
Dimitrios P. Sokolis
Keyword(s):  
Small Intestine ◽  
Orientation Angle ◽  
Axial Direction ◽  
Material Model ◽  
Biomechanical Properties ◽  
Intestinal Wall ◽  
Model Parameters ◽  
Material Models ◽  
Hyper Elastic ◽  
Rat Tissue

Multiaxial testing of the small intestinal wall is critical for understanding its biomechanical properties and defining material models, but limited data and material models are available. The aim of the present study was to develop a microstructure-based material model for the small intestine and test whether there was a significant variation in the passive biomechanical properties along the length of the organ. Rat tissue was cut into eight segments that underwent inflation/extension testing, and their nonlinearly hyper-elastic and anisotropic response was characterized by a fiber-reinforced model. Extensive parametric analysis showed a non-significant contribution to the model of the isotropic matrix and circumferential-fiber family, leading also to severe over-parameterization. Such issues were not apparent with the reduced neo-Hookean and (axial and diagonal)-fiber family model, that provided equally accurate fitting results. Absence from the model of either the axial or diagonal-fiber families led to ill representations of the force- and pressure-diameter data, respectively. The primary direction of anisotropy, designated by the estimated orientation angle of diagonal-fiber families, was about 35° to the axial direction, corroborating prior microscopic observations of submucosal collagen-fiber orientation. The estimated model parameters varied across and within the duodenum, jejunum, and ileum, corroborating histologically assessed segmental differences in layer thicknesses.

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