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.

Obstacle Impact Simulation of an ATV Using an Efficient Tire Model

2003 ◽  
Vol 31 (4) ◽  
pp. 248-269 ◽  
Author(s):  
R. Mousseau ◽  
G. Markale
Keyword(s):  
Element Model ◽  
Rigid Body Dynamics ◽  
Dynamic Loads ◽  
Tire Model ◽  
Considerable Effort ◽  
Impact Simulation ◽  
Body Dynamics ◽  
Multi Body ◽  
Nonlinear Finite Element Model ◽  
Vehicle Development Process

Abstract When a vehicle travels over a large obstacle at a significant speed, dynamic loads are created that are severe enough to cause damage to its components. Prediction of these impact loads early in the design can greatly aid the vehicle development process. Thus, automobile manufactures have devoted considerable effort developing computer models to simulate durability events. An important part of any durability simulation is the tire model. This paper focuses on the problem of efficiently predicting dynamic loads that occur when an all terrain vehicle (ATV) impacts obstacle impact. An ATV simulation model that uses an efficient and simple tire model to represent the enveloping behavior and dynamic response was developed with the AUTOSIM multibody dynamics program. This program, using Kane's Method and symbolic algebra to automatically generate fully parametric simulations that are both efficient and easy to use, was used to model both the tire and ATV rigid body dynamics. This paper describes the combined ATV multi-body vehicle dynamics and tire simulation. To demonstrate the effectiveness of tire simulation, results from the efficient tire model isolated from the vehicle are compared to output from a nonlinear finite element model. Also, the paper compares results from the full vehicle ATV simulation and a field test.

Modal Based Geometric Stiffening Formulation for Dynamics Simulation of Multibody Systems

2011 ◽  
Author(s):  
Fengxia Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Dynamics Simulation ◽  
Reduced Model ◽  
Reduced Models ◽  
Modal Reduction ◽  
Body Dynamics ◽  
Geometric Stiffening ◽  
Multi Body

This work concerns the implementation of nonlinear modal reduction to flexible multi-body dynamics. Linear elastic theory will lead to instability issues with rotating beamlike structures, due to the neglecting of the membrane-bending coupling on the beam cross-section. During the past decade, considerable efforts have been focused on the derivation of geometric nonlinear formulation based on nodal coordinates. In this work, in order to improve the convergence characteristic and also to reduce the computation time in flexible multi-body dynamics, which is extremely important for complicated large systems, a standard modal reduction procedure based on matrix operation is developed with essential geometric stiffening nonlinearities retained in the equation of motion. The example used in this work is a rotating Euler-Bernoulli beam, two nonlinear reduced models were established based on modal coordinates, the first reduced model created from theoretical bending and axial mode shapes by Galerkin method; the second reduced model is derived by the standard matrix operator from a full finite element model. Transient simulation results of lower degrees of freedom from above two reduced models are compared with those obtained from full nonlinear finite element model.

scholarly journals Investigations on Vehicle Interaction with CWR Tracks Considering Some Aspects of Rail Support Modulus

2018 ◽  
Author(s):  
Seyed-Ali Mosayebi ◽  
Jabbar-Ali Zakeri ◽  
Morteza Esmaeili
Keyword(s):  
Element Model ◽  
Dynamic Interaction ◽  
Railway Track ◽  
Technical Literature ◽  
Preliminary Model ◽  
Body Dynamics ◽  
Continuous Welded Rail ◽  
Rail Irregularity ◽  
Comparison Of The Results ◽  
Multi Body

One of the important parameters for controlling the behavior of continuous welded rail (CWR) in railway tracks is rail support modulus. Reviewing the technical literature reveals some elapsed points in this regard such as continuous or discrete supports, V-shaped rail irregularity and geometrical stiffness which can considerably affect on the vehicle-track dynamic interaction. So, the present study was allocated to numerical investigating the effects of aforementioned parameters on the vehicle-track dynamic interaction. In this matter, the finite element model of ballasted railway track in conjunction with multi-body dynamics model of vehicle was developed and they simultaneously solved numerically. This preliminary model was verified through comparison of the results with published works in this area. Consequently the model was promoted considering continuous and discrete support condition, implementing the V-shaped irregularity and geometrical stiffness. In each step, the results of the extended models were completely presented in the form track structure response.

Modal and Strength Analysis of Crankshaft in Piston Compressor

2014 ◽  
Vol 945-949 ◽  
pp. 676-679
Author(s):  
Zhi Juan Sun ◽  
Jing Tao Dai
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Theoretical Basis ◽  
Piston Compressor ◽  
Element Model ◽  
Strength Analysis ◽  
Dynamics Model ◽  
Body Dynamics ◽  
Comprehensive Performance ◽  
Multi Body

For research on comprehensive performance of crankshaft in piston compressor, multi-body dynamics model was built to get mechanical boundary conditions of the crankshaft, and the fatigue strength was verified; Finite element model (FEM) of the crankshaft was established, and the 1st 6 modal of the crankshaft was obtained. The results showed that fatigue strength and dynamic characteristic of the crankshaft was qualified. Theoretical basis could be provided for optimize the crankshaft’s structure by fatigue strength and modal analysis.

Multi-body dynamics co-simulation of hoisting wire rope

2017 ◽  
Vol 53 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Qing Huang ◽  
Zhi Li ◽  
Hong-qian Xue
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Dynamic Model ◽  
Loading Condition ◽  
Element Model ◽  
Wire Rope ◽  
Body Dynamics ◽  
Hoisting System ◽  
Multi Body

As more wire ropes with complex construction are used in the hoisting system of a crane, it becomes more necessary to predict the risks of the hoisting operation. Especially the wire rope, dynamic analysis is required to manage the potential risk in advance. Thus, in this article, a co-simulation method based on multi-body dynamics and finite element method is proposed to determine the dynamic responses of a hoisting system and wire rope. We developed a dynamic model of hoisting system based on ADAMS/Cable to formulate the time history response of dynamic force on wire rope, which could be used as the loading condition in the posterior finite element model. A three-dimensional geometric model for the multi-layered strands wire rope with a construction of 1+7+7 / 7+14 wires is implemented in the finite element analysis software ABAQUS, and both static and dynamic analyses are presented. The static analysis result of force–strain relation is compared with several experiment data, and the finite element model is proved accurate and reliable. In the latter case, the force–time curves obtained by dynamic model are imported to finite element model as loading condition to accomplish dynamic analysis. The co-simulation results of hoisting wire rope’s behavior subjected to dynamic loading during the hoisting process are carried out and discussed. The stress distribution and stress spectrum of wire rope are obtained, and the results show that the most dangerous regions are the lateral side of wire rope, especially the contact area of two wires in strands.

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.

Lightweight Design for a New Tracked Triangular Wheel Structure

2013 ◽  
Vol 744 ◽  
pp. 78-82
Author(s):  
Jun Wen Xing ◽  
Hong Wu Pu ◽  
Xiang Zheng Meng ◽  
Li Qun Bao
Keyword(s):  
Finite Element ◽  
Lightweight Design ◽  
Element Model ◽  
Simulation Software ◽  
Dynamics Simulation ◽  
Wheeled Vehicle ◽  
Body Dynamics ◽  
Dry Soil ◽  
Multi Body ◽  
Structure Properties

A new tracked triangular wheel structure was introduced. A whole tracked triangular wheeled vehicle model was built in multi-body dynamics simulation software RecurDyn, and its climbing obstacle performance on the dry soil road was simulated. The author put the simulation results as loading conditions of finite element model. Finite element calculation and lightweight design for tracked triangular wheel base frame were completed. The results showed that the weight of the base frame reduced by 69.8%, the structure properties of the base frame improved, and the lightweight design goal was achieved.

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