scholarly journals Three-Dimensional Biomechanical Analysis of the Bovine Humerus

2014 ◽  
Vol 11 (1-2) ◽  
pp. 13-24 ◽  
Author(s):  
José Benito Bouza-Rodríguez ◽  
Luz Calia Miramontes-Sequeiros

There are few reports on the biomechanical analysis of the animal humerus. In this study, a three-dimensional finite element model of the bovine humerus was created, and loaded with the physiological forces acting when the cow is falling or jumping (weight and impact forces). Subsequently the corresponding stress and strain distribution in the humerus for different inclined positions of bone was determined.The highest stress concentration occurred in the distal humeral diaphysis, both when only the reaction and load transfer forces were considered and when muscle forces were included too, although when muscle forces were included these maximum stresses decreased. In the distal humeral diaphysis, an increase was also observed in the cortical thickness; this may be a bone adaptation to reduce the maximum stresses. By understanding these bone adaptation processes at regional level, non-pharmacological treatments to some bone pathologies could be developed, mainly the ones characterized by loss of bone mass.Furthermore, taking into account both the humerus fracture strength and the maximum force that muscles can make without breaking, it is deduced that during jumping or falling the cow must maintain the humerus as vertical as possible to better bear the impact. This is in congruity with what was observed.The interest of this study is in improving the knowledge of animal humerus biomechanics and its application in orthopaedic design and surgical treatments.

Author(s):  
Omar Awad ◽  
Yahia M. Al-Smadi

Boxing or martial arts are games where players chests are subject to lateral impact, the impact loads travel through skin, ribs, mediastinum (i.e. a thoracic compartment) and then through the skeleton to the rest of the body. When thorax is subject to lateral force exceeding the elastic limit of thoracic compartment, players often go in shock demanding prompt resuscitation. This paper investigates the thorax response of boxer being subject to lateral impact followed by Cardiopulmonary resuscitation (CPR). Due to complexity of thorax structure and materials, three dimensional finite element model in ANSYS was created to perform the computational biomechanical analysis of two-stage loading (i.e. lateral impact load and CPR forces). Model input parameters such as material, loading and boundary conditions have been defined. Post processing values such as deformations and stresses have been presented.


2020 ◽  
Vol 10 (12) ◽  
pp. 1010
Author(s):  
Deepika Konakanchi ◽  
Amy L. de Jongh Curry ◽  
Robert S. Waters ◽  
Shalini Narayana

Transcranial magnetic stimulation (TMS) is a promising, non-invasive approach in the diagnosis and treatment of several neurological conditions. However, the specific results in the cortex of the magnitude and spatial distribution of the secondary electrical field (E-field) resulting from TMS at different stimulation sites/orientations and varied TMS parameters are not clearly understood. The objective of this study is to identify the impact of TMS stimulation site and coil orientation on the induced E-field, including spatial distribution and the volume of activation in the cortex across brain areas, and hence demonstrate the need for customized optimization, using a three-dimensional finite element model (FEM). A considerable difference was noted in E-field values and distribution at different brain areas. We observed that the volume of activated cortex varied from 3000 to 7000 mm3 between the selected nine clinically relevant coil locations. Coil orientation also changed the induced E-field by a maximum of 10%, and we noted the least optimal values at the standard coil orientation pointing to the nose. The volume of gray matter activated varied by 10% on average between stimulation sites in homologous brain areas in the two hemispheres of the brain. This FEM simulation model clearly demonstrates the importance of TMS parameters for optimal results in clinically relevant brain areas. The results show that TMS parameters cannot be interchangeably used between individuals, hemispheres, and brain areas. The focality of the TMS induced E-field along with its optimal magnitude should be considered as critical TMS parameters that should be individually optimized.


2012 ◽  
Vol 192 ◽  
pp. 29-36
Author(s):  
Yu Xin Wang ◽  
Qing Chun Wang ◽  
Jian Rong Fu ◽  
Hong Hai Qiao

Effect of hard point of the engine hood on the head injury during the vehicle-human collision was studied to improve the design of engine hood. Firstly, the current common model of the engine hood was established with three-dimensional finite element modeling software, and 20 areas were divided, also a standard head finite element model was imported, secondly, each area of the engine hood was clashed by the standard head model, then the impact on the head injure was analyzed and the hard point of the hood area was achieved, thirdly, the optimization of the inside and outside panel materials and the plate structure were carried out to reduce the head damage. The simulation results show that the engine hood after optimization gave less damage to the head, which means the research carried out here is of a good reference to the engine hood optimization design for human protection


2010 ◽  
Vol 118-120 ◽  
pp. 147-150
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Yong Gao ◽  
Wen Lin Liu ◽  
Zhong Hu Jia

Three-dimensional finite element model of a cracked bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of load transfer were compared with results from finite element analysis. The results show that three-dimensional finite element model of cracked bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of hole mod and crack on the load transfer behaviour of single lap bolted joints. The results show that hole mode has big effect on load transfer of cracked bolted joint. In the whole progress of crack growth, the load transfer through bolt 1 decrease, and almost all of the load duduction of bolt 1 transfer into blot 2 rather than into bolt 3.


Author(s):  
Tsu-Te Wu

This paper presents the dynamic simulation of the 6M drum with a locking-ring type closure subjected to a 4.9-foot drop. The drum is filled with water to 98 percent of overflow capacity. A three dimensional finite-element model consisting of metallic, liquid and rubber gasket components is used in the simulation. The water is represented by a hydrodynamic material model in which the material’s volume strength is determined by an equation of state. The explicit numerical method based on the theory of wave propagation is used to determine the combined structural response to the torque load for tightening the locking-ring closure and to the impact load due to the drop.


Author(s):  
Noureddine Djebbar ◽  
Abdessamed Bachiri ◽  
Benali Boutabout

The design of an implant thread plays a fundamental role in the osseointegration process, particularly in low-density bone. It has been postulated that design features that maximize the surface area available for contact may improve mechanical anchorage and stability in cancellous bone. The primary stability of a dental implant is determined by the mechanical engagement between the implant and bone at the time of implant insertion. The contact area of implant-bone interfaces and the concentrated stresses on the marginal bones are principal concerns of implant designers. Numerous factors influence load transfer at the bone-implant interface, for example, the type of loading, surface structure, amount of surrounding bone, material properties of the implant and implant design. The purpose of this study was to investigate the effects of the impact two different projectile of implant threads on stress distribution in the jawbone using three-dimensional finite element analysis.


2014 ◽  
Vol 638-640 ◽  
pp. 675-679 ◽  
Author(s):  
Huan Sheng Mu ◽  
Ling Gao

This paper presents a non-probabilistic method for reliability analysis of cement mixing composite foundations. First, the load transfer mechanism of composite foundations is described. Then a three-dimensional finite element model of cement mixing composite foundation under embankment is built. The settlement of subgrade is analyzed. Finally, a non-probabilistic reliability method is used to investigate the settlement reliability. The results show that the cement mixing composite foundation can significantly improve the compressibility of soft soil.


2014 ◽  
Vol 1003 ◽  
pp. 78-84
Author(s):  
Xiao Ning Chen ◽  
Jin Long Zhao ◽  
Yun Sheng Zhang ◽  
Bin Zhang

Theoretical deducing, simulated lightning test and finite element simulation are used to research the mechanism and state of lightning damage of the aircraft composites sandwich panels. It provides the basis for the design of the aircraft lightning protection. The three-dimensional finite element model of the composites panel is constructed through the thermal electrical-mechanical multi-Physics coupling field. According to the structure and the role process, the lightning effect of the aircraft composites is analysed to study the damage mechanism and the possible state of the composites panel that is struck by lightning. The impact current generator is used to carry out the simulated lightning test to observe the lightning effect of the composites panel. By comparing the results of the test and the simulation, the effectiveness and the correctness of the simulation are verified.


2012 ◽  
Vol 178-181 ◽  
pp. 1147-1151
Author(s):  
Yun Liang Li ◽  
Luo Ke Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue

Dowels are used in jointed plain concrete pavements to provide lateral load transfer across transverse joint through shear force, effective load transfer at lateral joints can reduces stresses in the slabs. Steel dowels are generally used in engineering practice, but corrosive substance such as carbon chloride ions ,dioxide can free access and easily dispersed along the length of the steel dowels, therefor rapid corrosion can occur which can lead to premature failure of the transverse joint. Glass fibre reinforced polymer (GFRP) dowels have been recently introduced as a possible solution to the corrosion problem posed by steel dowels. This paper given a comparison of the maximum shear forces of none eroded GFRP dowel at the joint face with the help of a three-dimensional finite-element model and investigated the performance of GFRP dowels under static and cyclic load. According to the experiment results, the larger-diameter GFRP dowels were found to perform the best in this study.


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