Generating Parameters of a Multi-Body Meniscus Model From Experimental Data

2010 ◽  
Author(s):  
Gavin Paiva ◽  
Trent Guess ◽  
Mohammad Kia
Keyword(s):  
Experimental Data ◽  
Material Properties ◽  
Element Model ◽  
Contact Forces ◽  
Large Strains ◽  
Body Model ◽  
Physiological Loading ◽  
Tension And Compression ◽  
Multi Body ◽  
Force Displacement

The meniscus is a crucial anatomical structure in the mechanics of vertebrate hind legs [3]. Menisci function primarily by distributing the tibio-femoral contact forces, and thereby reducing the stress in the articular cartilage of the knee joint. As the meniscus is a flexible body that undergoes large strains, it is typically ignored in rigid-body biomechanical simulations. One documented method of including this factor in the multi-body framework is to represent the menisci as discrete bodies connected by linear 6-axis spring and damper elements [2]. The difficulty arises in determining the stiffnesses and viscosities that correspond to the material properties of the real meniscus. Material properties have previously been determined by a design of experiments approach to match the force displacement behavior of a multi-body model to a linear finite element model. This study explores a method of determining the said properties from experimental data collected in a semi-physiological loading, where the force orientation is principally circumferential tension and compression in the other directions.

scholarly journals Finite Element Simulations of the ID Venous System to Treat Venous Compression Disorders: From Model Validation to Realistic Implant Prediction

2021 ◽  
Author(s):  
Alissa Zaccaria ◽  
Francesco Migliavacca ◽  
David Contassot ◽  
Frederic Heim ◽  
Nabil Chakfe ◽  
...  
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Element Model ◽  
Venous System ◽  
Venous Compression ◽  
Risk Of Rupture ◽  
Model Reliability ◽  
The Impact ◽  
Force Displacement ◽  
Realistic Geometry

AbstractThe ID Venous System is an innovative device proposed by ID NEST MEDICAL to treat venous compression disorders that involve bifurcations, such as the May-Thurner syndrome. The system consists of two components, ID Cav and ID Branch, combined through a specific connection that prevents the migration acting locally on the pathological region, thereby preserving the surrounding healthy tissues. Preliminary trials are required to ensure the safety and efficacy of the device, including numerical simulations. In-silico models are intended to corroborate experimental data, providing additional local information not acquirable by other means. The present work outlines the finite element model implementation and illustrates a sequential validation process, involving seven tests of increasing complexity to assess the impact of each numerical uncertainty separately. Following the standard ASME V&V40, the computational results were compared with experimental data in terms of force-displacement curves and deformed configurations, testing the model reliability for the intended context of use (differences < 10%). The deployment in a realistic geometry confirmed the feasibility of the implant procedure, without risk of rupture or plasticity of the components, highlighting the potential of the present technology.

Multi-body model of a bobsleigh: comparison with experimental data

2010 ◽  
Vol 25 (2) ◽  
pp. 185-201 ◽  
Author(s):  
Francesco Braghin ◽  
Federico Cheli ◽  
Mauro Donzelli ◽  
Stefano Melzi ◽  
Edoardo Sabbioni
Keyword(s):  
Experimental Data ◽  
Body Model ◽  
Multi Body ◽  
Comparison With Experimental Data

A Finite Element Investigation of a Functional Spine Unit in Conjunction With a Multi-Body Model of the Lumbar Spine for Impact Dynamics

Volume 2 ◽  
2004 ◽  
Author(s):  
Volkan Esat ◽  
Memis Acar
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Reaction Force ◽  
Element Model ◽  
Fe Model ◽  
Body Model ◽  
Spine Model ◽  
Spinal Segments ◽  
Whole Spine ◽  
Multi Body

In this study, the finite element (FE) technique was used in conjunction with multi-body modelling to simulate and analyse the dynamic behaviour of the spinal segments in order to investigate the effects of impact loadings on the lumbar spine. A 3-D multi-body model of the lumbar spine and an FE model of the L2-L3 motion segment were developed. Both models were validated for flexion and compression loadings, showing good agreements with a previously validated lumbar spine model. The predictions of the multi-body model under dynamic impact loading conditions such as reaction forces at lumbar motion segments were employed as force boundary conditions for the finite element model of the selected functional spine unit (FSU). Stress and pressure in the intervertebral disc element and the reaction force at a specific vertebral level were presented. This approach has the potential to more realistically simulate the dynamics of spinal segments and whole spine, and study the effects on spinal elements.

Numerical Analysis of Vehicle Occupant Responses during Rear Impact Using a Human Body Model

2014 ◽  
Vol 566 ◽  
pp. 480-485 ◽  
Author(s):  
Jonas A. Pramudita ◽  
Shunsuke Kikuchi ◽  
Yuji Tanabe
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Real World ◽  
Element Model ◽  
Vehicle Occupant ◽  
Body Model ◽  
Rear Impact ◽  
Multi Body ◽  
Impact Simulations

Understanding vehicle occupant responses during real-world rear collision accidents is very important in the development of appropriate safety technologies for neck injury lessening. In this study, numerical analysis of vehicle occupant responses during rear impact were conducted by using a human multi-body model, a seat finite element model and crash accelerations obtained from real-world accidents. The human multi-body model was developed based on the body characteristics of a typical Japanese male, including the outer body geometry, inertial properties of body segments and passive joint characteristics. The seat finite element model was extracted from a detailed car finite element model. A small modification was done to the seat model to deal with the rear impact simulations. The crash accelerations were obtained from the drive recorder database of rear collision accidents occurred in Japan. Several crash accelerations were selected and used as input conditions during the rear impact simulations. Kinematic responses of the occupants during the accidents can be reasonably predicted by the simulations. Furthermore, different level of accelerations leads to different kinematics responses that may cause variation in injury occurrence and injury severity.

DOE Analysis of the Effects of Geometrical Parameters on the Self-Piercing Riveting of Aluminium Alloy AA6060T4

2011 ◽  
Vol 473 ◽  
pp. 733-738 ◽  
Author(s):  
Giuseppe Casalino
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Statistical Analysis ◽  
Element Model ◽  
The Self ◽  
Geometrical Parameters ◽  
Displacement Curve ◽  
Design Problems ◽  
Riveting Process ◽  
Force Displacement

The design of experiments (DOE) is a very useful tool to design and analyze complicated industrial design problems. They help to understand the variability a manufacturing process by investigating which parameters and their interaction mainly affect the output repeatability. As a consequence, it enables to individuate the combination of parameters that optimize the output avoiding misinterpretation that can be due to the singularity of the experimental data. In this study the factorial analysis was used to investigate the effects of the major geometrical parameters on the shape of the force-displacement curve of the self piercing riveting (SPR) process. A full two level three-factorial design (23) was completed, three-way interaction was not considered. The statistical analysis was carried out at four different points of the force-rivet displacement curve. These points can be considered critical since they limit the four steps in which the process is commonly divided for studying purpose. The experimental data did not fulfil the required design points, the missing points were obtained by a finite element model of the riveting process, which furnished the force versus the rivet run.

scholarly journals The biomechanical role of the chondrocranium and sutures in a lizard cranium

2017 ◽  
Vol 14 (137) ◽  
pp. 20170637 ◽  
Author(s):  
Marc E. H. Jones ◽  
Flora Gröning ◽  
Hugo Dutel ◽  
Alana Sharp ◽  
Michael J. Fagan ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Element Model ◽  
South American ◽  
Anterior Portion ◽  
Body Dynamics ◽  
Tension And Compression ◽  
Strain Magnitude ◽  
Multi Body ◽  
Complex Distribution

The role of soft tissues in skull biomechanics remains poorly understood. Not least, the chondrocranium, the portion of the braincase which persists as cartilage with varying degrees of mineralization. It also remains commonplace to overlook the biomechanical role of sutures despite evidence that they alter strain distribution. Here, we examine the role of both the sutures and the chondrocranium in the South American tegu lizard Salvator merianae . We use multi-body dynamics analysis (MDA) to provide realistic loading conditions for anterior and posterior unilateral biting and a detailed finite element model to examine strain magnitude and distribution. We find that strains within the chondrocranium are greatest during anterior biting and are primarily tensile; also that strain within the cranium is not greatly reduced by the presence of the chondrocranium unless it is given the same material properties as bone. This result contradicts previous suggestions that the anterior portion (the nasal septum) acts as a supporting structure. Inclusion of sutures to the cranium model not only increases overall strain magnitudes but also leads to a more complex distribution of tension and compression rather than that of a beam under sagittal bending.

Hunting Analysis of a Partially-Filled Railway Tank Car

2015 ◽  
Author(s):  
Iman Hazrati Ashtiani ◽  
Subhash Rakheja ◽  
A. K. W. Ahmed ◽  
Jimin Zhang
Keyword(s):  
Phase Relationship ◽  
General Purpose ◽  
Contact Forces ◽  
Geometric Constraints ◽  
Dynamic Responses ◽  
Contact Method ◽  
Lateral Dynamics ◽  
Body Model ◽  
Liquid Load ◽  
Multi Body

General purpose railway tank cars similar to road tankers are known to transport liquid cargo in partial-fill state due to variations in liquid cargo density and governing axle load limits. It is widely reported that the cargo movements constitute additional forces and moments that could strongly affect the wheel-rail interactions and coupling forces, and thereby the directional dynamics of the wagon. In this study, the linear slosh theory is used to describe the liquid cargo movement in the roll plane by a simple pendulum, which is integrated into a comprehensive nonlinear multi-body model of a three-piece truck to study the effects of liquid cargo slosh on lateral dynamics of the tank car. The model also incorporates the nonlinear secondary suspension restoring and damping forces, attributed to friction of the wedges, using the non-smooth contact method in addition to the geometric constraints of various components. The wheel/rail contact forces are simulated considering non-elliptical wheel-rail contact using the FASTSIM algorithm. The lateral dynamic responses of the multi-body model of a freight car with partially filled liquid load and an equivalent rigid cargo are evaluated to study the effect of cargo movement on the critical speed and the wheelset hunting oscillations frequency. The results obtained considering different fill ratios of the liquid cargo suggest that the fluid slosh yields additional damping effect on the lateral dynamics of the car. Liquid cargo movement within partly-filled tank car could thus yield a beneficial influence on the wheelset hunting. This was evidenced from the phase relationship between the lateral oscillations of the pendulum and the bogie/wheelset. Consequently, a partially filled tanker resulted in relatively higher critical hunting velocity compared to that of the wagon with equivalent rigid cargo.

Multi-Body Damping of a Vane Cluster

2011 ◽  
Author(s):  
Andreas Hartung ◽  
Ulrich Retze
Keyword(s):  
Vibration Amplitude ◽  
Element Model ◽  
Analytical Models ◽  
Blade Vibration ◽  
Body Model ◽  
Good Comparison ◽  
Rigid Body Model ◽  
High Level ◽  
Multi Body ◽  
Level Of Agreement

Spring-damper systems are standard for reducing blade vibration amplitude at vane clusters. Spring-dampers can only be used with an altered geometry of the inner shrouds. In most cases a separation of the inner shrouds is inevitable. In this paper an alternative damping system without changes of the outer inner shroud geometry is developed and analyzed. Two analytical models — a simplified Rigid Body Model and a 3D Finite Element Model show, based on similar results, a good comparison. The analytical results were validated by shaker tests. A high level of agreement between simulation and test was achieved.

Design of Planar Miniaturized Mechanisms With Flexural Pivots

2000 ◽  
Author(s):  
Jürgen Schönherr ◽  
Jörg Müglitz
Keyword(s):  
Medical Devices ◽  
Material Properties ◽  
Mechanism Analysis ◽  
Modeling And Analysis ◽  
Body Model ◽  
Measuring Devices ◽  
Straight Line ◽  
Kinematic Performance ◽  
Micro Systems ◽  
Multi Body

Abstract The paper deals with synthesis, modeling and analysis of mechanisms with flexural pivots preferably used in micro-systems, measuring devices, or medical devices. Among other things, it will be shown that rotary joints can be replaced by flexural pivots so that the kinematic performance will be kept. Already in the phase of kinematic design, one has pay attention to material properties, load, and strain to ensure both the mobility and the strength of the mechanism. Using two examples, a Robert’s straight line generator and a trunk-like motion generating mechanism, it is shown here, how a relatively simple multi-body model can be used effectively for mechanism analysis and optimization.

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