Development and Validation of A C0–C7 FE Complex for Biomechanical Study

2005 ◽  
Vol 127 (5) ◽  
pp. 729-735 ◽  
Author(s):  
Qing Hang Zhang ◽  
Ee Chon Teo ◽  
Hong Wan Ng
Keyword(s):  
Current Model ◽  
Drop Impact ◽  
Biomechanical Study ◽  
Fe Model ◽  
Midsagittal Plane ◽  
Male Cadaver ◽  
Geometrical Data ◽  
Fe Complex ◽  
Development And Validation ◽  
Head Neck

In this study, the digitized geometrical data of the embalmed skull and vertebrae (C0–C7) of a 68-year old male cadaver were processed to develop a comprehensive, geometrically accurate, nonlinear C0–C7 FE model. The biomechanical response of human neck under physiological static loadings, near vertex drop impact and rear-end impact (whiplash) conditions were investigated and compared with published experimental results. Under static loading conditions, the predicted moment-rotation relationships of each motion segment under moments in midsagittal plane and horizontal plane agreed well with experimental data. In addition, the respective predicted head impact force history and the S-shaped kinematics responses of head-neck complex under near-vertex drop impact and rear-end conditions were close to those observed in reported experiments. Although the predicted responses of the head-neck complex under any specific condition cannot perfectly match the experimental observations, the model reasonably reflected the rotation distributions among the motion segments under static moments and basic responses of head and neck under dynamic loadings. The current model may offer potentials to effectively reflect the behavior of human cervical spine suitable for further biomechanics and traumatic studies.

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

Development and validation of a FE model of a mining vehicle tyre

2014 ◽  
Vol 65 (2/3) ◽  
pp. 176 ◽  
Author(s):  
Zhanbiao Li ◽  
Aleksander Tonkovich ◽  
Sante Dicecco ◽  
William Altenhof ◽  
Henry Hu ◽  
...  
Keyword(s):  
Fe Model ◽  
Development And Validation

Micromechanical Model of a Collagen Based Tendon Surrogate: Development and Validation

2012 ◽  
Author(s):  
Shawn P. Reese ◽  
Jeffrey A. Weiss
Keyword(s):  
Finite Element ◽  
Computational Model ◽  
Physical Model ◽  
Micromechanical Model ◽  
Tensile Loading ◽  
Fe Model ◽  
Damage Mechanisms ◽  
High Importance ◽  
Force Transfer ◽  
Development And Validation

In tendons and ligaments, collagen is organized hierarchically into nanoscale fibrils, microscale fibers and mesoscale fascicles. Force transfer across scales is complex and poorly understood, and macroscale strains are not representative of the microscale strains [1]. Since innervation, the vasculature, damage mechanisms and mechanotransduction occur at the microscale, understanding such multiscale interactions is of high importance. In this study, a physical model was used in combination with a computational model to isolate and study the mechanisms of force transfer between scales. The objectives of this study were to develop a collagen based tendon surrogate for use as a physical model and subject it to tensile loading, and to create and validate a 3D micromechanical finite element (FE) model of the surrogate.

Multi-Objective Model Updating Optimization Considering Orthogonality

2019 ◽  
Vol 14 (6) ◽  
Author(s):  
Braden T. Warwick ◽  
Il Yong Kim ◽  
Chris K. Mechefske
Keyword(s):  
Mode Shape ◽  
Degrees Of Freedom ◽  
Pareto Front ◽  
Model Updating ◽  
Current Model ◽  
Physical Reality ◽  
Frequency Error ◽  
Fe Model ◽  
Multi Objective ◽  
Objective Model

The coordinate orthogonality check (CORTHOG) and multi-objective optimization considering pseudo-orthogonality as an objective function are introduced to overcome several limitations present in current model updating methods. It was observed that the use of the CORTHOG to remove four inaccurate degrees-of-freedom (DOF) was able to increase the orthogonality between mode shape vectors. The multi-objective model updating process generated a Pareto front with 38 unique optimal solutions. Four critical points were identified along the Pareto front, of which decreased the natural frequency error by greater than 2.84% and further increased the orthogonality between mode shape vectors. Therefore, it has been demonstrated that both steps of the methodology are critical to significantly reduce the overall errors of the system and to generate a finite element (FE) model that best describes physical reality. Additionally, the methodology introduced in this work generated a feasible computational runtime allowing for it to be easily adapted to widespread applications.

Investigation of Anteroposterior Head-Neck Responses during Severe Frontal Impacts Using a Brain-Spinal Cord Complex FE Model

2006 ◽  
Author(s):  
Hideyuki Kimpara ◽  
Yuko Nakahira ◽  
Masami Iwamoto ◽  
Kazuo Miki ◽  
Kazuhiko Ichihara ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Fe Model ◽  
Frontal Impacts ◽  
Head Neck

Vibrational and Acoustical Analysis of Trussed Railroad Bridge Under Moving Loads

2012 ◽  
Author(s):  
R. Daniel Costley ◽  
Henry Diaz-Alvarez ◽  
Mihan H. McKenna
Keyword(s):  
Structural Damage ◽  
Current Model ◽  
Element Model ◽  
Vehicle Suspension ◽  
Fe Model ◽  
Vibrational Modes ◽  
Moving Loads ◽  
Vehicle Loading ◽  
Vibration Responses ◽  
Railroad Bridge

A Finite Element model has been developed for a Pratt truss railroad bridge located at Ft. Leonard Wood, MO. This model was used to investigate the vibration responses of a bridge under vehicle loading. Modeling results have been obtained for a single axle with two wheels traversing the bridge at different speeds. The current model does not include the effects of vehicle suspension. Superposition of multiple axles has been used to represent a locomotive transiting the bridge. The output of the vibration response was used as an input to an acoustic FE model to determine which vibrational modes radiate infrasound. The vibration and acoustic models of the railroad bridge will be reviewed, and results from the analysis will be presented. Measurements from an accelerometer mounted on the bridge agree reasonably well with model results. Infrasound could potentially be used to remotely provide information on the capacity and number of the vehicles traversing the bridge and to monitor the bridge for significant structural damage.

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