scholarly journals Dynamic Properties of Cortical Bone Tissue: Impact Tests and Numerical Study

2011 ◽  
Vol 70 ◽  
pp. 387-392
Author(s):  
Adel A. Abdel-Wahab ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Impact Loading ◽  
Numerical Study ◽  
Numerical Models ◽  
Dynamic Properties ◽  
High Energy ◽  
Finite Element Software

Bone is the principal structural component of a skeleton: it assists the load-bearing framework of a living body. Structural integrity of this component is important; understanding of its mechanical behaviour up to failure is necessary for prevention and diagnostic of trauma. Bone fractures occur in both low-energy trauma, such as falls and sports injury, and high-energy trauma, such as car crash and cycling accidents. By developing adequate numerical models to predict and describe the deformation and fracture behaviour up to fracture of a cortical bone tissue, a detailed study of reasons for, and ways to prevent or treatment methods of, bone fracture could be implemented. This study deals with both experimental analysis and numerical simulations of this tissue and its response to impact dynamic loading. Two areas are covered: Izod tests for quantifying a bone’s behaviour under impact loading, and a 3D finite-element model simulating these tests. In the first part, properties of cortical bone tissue were investigated under impact loading condition. In the second part, a 3D numerical model for the Izod test was developed using the Abaqus/Explicit finite-element software. Bone has time-dependent properties – viscoelastic – that were assigned to the specimen to simulate the short term event, impact. The developed numerical model was capable of capturing the behaviour of the hammer-specimen interaction correctly. A good agreement between the experimental and numerical data was found.

Analysis of Deformation Characteristics of Cortical Bone Tissue

2012 ◽  
Vol 188 ◽  
pp. 118-123 ◽  
Author(s):  
Si Min Li ◽  
Emrah Demirci ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Vickers Hardness ◽  
Mechanical Response ◽  
Numerical Models ◽  
Deformation Behaviour ◽  
Cutting Tools ◽  
Deformation Characteristics ◽  
Hardness Tests

Numerical modeling of bones is necessary for design of efficient surgical cutting tools that can provide low cutting forces, reduce damage and prevent thermal necrosis of bone tissue. Development of realistic numerical models of cortical bone tissue requires deep knowledge of its deformation behaviour. Deformation mechanisms of bones differ from those of metals, polymers and composites since bones consist of a living tissue with hierarchical microstructure. The aim of this study is to analyse deformation characteristics of the cortical bone tissue from both experimental and numerical perspectives. Initially, Vickers hardness tests were conducted at various anatomical positions on a cross-section of a bovine femur bone to observe location-based variation of its mechanical response. Various load magnitudes ranging between 1 kgf and 100 kgf were applied in the Vickers hardness tests to analyse the effect of anisotropy on damage evolution. These tests were simulated using a finite element scheme to reproduce the mechanical behaviour of bones in indentation. Finally, results of the hardness tests were compared with those obtained from finite element simulations.

scholarly journals A Numerical Study on the Performance of GFRP RC Beams Exposed to High Temperature

2020 ◽  
Vol 13 (2) ◽  
pp. 136-143
Author(s):  
Nuha Hussein Ali ◽  
Haitham Al-Thairy
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Numerical Model ◽  
Elevated Temperatures ◽  
Numerical Study ◽  
Reinforced Concrete Beams ◽  
Temperature History ◽  
Effect Of Temperature ◽  
Rc Beams ◽  
Finite Element Software

This paper presents and validates a numerical model utilizing the nonlinear finite element software ABAQUS/Standard to simulate the performance and failure of GFRP reinforced concrete beams under high temperature. A numerical model was firstly developed by selecting the proper geometrical and material modelling parameters with suitable analysis procedure available in ABAQUS/Standard. The developed numerical model was verified by comparing numerical results with the corresponding results of experimental test extracted from current study on GFRP-RC beams under different elevated temperatures ranges from (20 to 600ºC). Validation results have indicated the accuracy of the suggested numerical model. The validated numerical model was implemented to investigate the effect of important parameters on the performance and maximum load of GFRP-RC beams under different elevated temperatures that are not considered in the current experimental tests. These parameters include effect of exposed time or time- temperature history; effect of temperature distribution around the beams cross-section. Results indicate that the finite element software ABAQUS/Standard can reasonably predict the performance and ultimate load of GFRP-RC beams under different elevated temperatures.

Analysis of Pipe-Soil Interaction for a Miniature Pipejacking

2006 ◽  
Vol 22 (3) ◽  
pp. 213-220 ◽  
Author(s):  
K. J. Shou ◽  
F. W. Chang
Keyword(s):  
Finite Element ◽  
Failure Mechanism ◽  
Physical Modeling ◽  
Driving Force ◽  
Numerical Models ◽  
Surface Subsidence ◽  
Finite Element Software

AbstractIn this study, physical and numerical models were used to analyze pipe-soil interaction during pipejacking work. After calibrating with the physical modeling results, the finite element software ABAQUS [1] was used to study the pipejacking related behavior, such as surface subsidence, failure mechanism, pipe-soil interaction, etc. The results show that the driving force in the tunnelling face is very important and critical for pipejacking. Surface subsidence is mainly due to the lack of driving force, however, excessive driving force could cause the unfavorable surface heaving problem. It also suggests that the depth of the pipe is critical to determine a proper driving force to stabilize the tunnelling face.

On the Design and Analysis of Acoustic Horns for Ultrasonic Welding Teflon Encapsulated O-Ring

2013 ◽  
Vol 753-755 ◽  
pp. 402-406
Author(s):  
Kuen Ming Shu ◽  
Yu Jen Wang ◽  
Hoa Shen Yen
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
High Energy ◽  
Ultrasonic Welding ◽  
Ultrasonic Machining ◽  
Analysis And Design ◽  
Vital Part ◽  
Finite Element Software ◽  
Acoustic Horns

The acoustic horn plays a very vital part in high energy ultrasonic machining, and its design is critical to the quality and the efficiency of ultrasonic machining. This paper performs the analysis and design of acoustic horns for ultrasonic welding Teflon encapsulated O-ring by employing ANSYS finite element software. Firstly, the theoretical dimensions of the horns are calculated. Moreover, their natural frequencies and amplitudes are obtained through the simulations of ANSYS.

scholarly journals Numerical model of the nanoindentation test based on the digital material representation of the Ti/TiN multilayers

2015 ◽  
Vol 33 (2) ◽  
pp. 348-355 ◽  
Author(s):  
Konrad Perzyński ◽  
Radosław Wiatr ◽  
Łukasz Madej
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Cellular Automata ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Nanoindentation Test ◽  
Cellular Automata Model ◽  
Finite Element Software ◽  
Specific Morphology ◽  
Digital Material

AbstractThe developed numerical model of a local nanoindentation test, based on the digital material representation (DMR) concept, has been presented within the paper. First, an efficient algorithm describing the pulsed laser deposition (PLD) process was proposed to realistically recreate the specific morphology of a nanolayered material in an explicit manner. The nanolayered Ti/TiN composite was selected for the investigation. Details of the developed cellular automata model of the PLD process were presented and discussed. Then, the Ti/TiN DMR was incorporated into the finite element software and numerical model of the nanoindentation test was established. Finally, examples of obtained results presenting capabilities of the proposed approach were highlighted.

scholarly journals Verification of the flexion and shear behavior in masonry panels accordance to ABNT NBR 15961-1 (2011), EN 1996-1-1 (2005) and ACI TMS 530 (2013)

2018 ◽  
Vol 11 (4) ◽  
pp. 673-685
Author(s):  
R. C. MATA ◽  
C. S. RAMOS ◽  
M. L. C. SILVA
Keyword(s):  
Computer Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Design Criteria ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Modelling Procedure ◽  
Increasing Trend ◽  
American Standard ◽  
Compression Level

Abstract This paper presents a numerical analysis of the mechanical behavior of structural masonry panels submitted to horizontal and vertical stresses. To evaluate the design process of these structures, the results obtained by the computer simulations were compared with the results determined by the design criteria of ABNT NBR 15961-1 (2011), ACI TMS 530 (2013) and EN 1996-1-1 (2005). The finite element software DIANA v.9.3 was used to simulate two-dimensional models with the simplified micro modelling procedure. The results obtained by the normative standards were more conservative than the results of the numerical model, as expected. With the increase of the pre-compression level, the computer simulation has demonstrated the increasing trend of the values of resistant forces, besides the change of the way of rupture of the panels. Among the three standards evaluated, the American Standard was the most conservative.

scholarly journals COMPARATIVE ANALYSIS OF MONOCORTICAL AND BICORTICAL METHODS OF INSTALLING MINI-IMPLANTS

2021 ◽  
pp. 38-40
Author(s):  
O.Yu. Rivis ◽  
V.S. Melnyk ◽  
M.V. Rivis ◽  
K.V. Zombor
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Comparative Analysis ◽  
Cortical Bone ◽  
Bone Tissue ◽  
Orthodontic Treatment ◽  
The Finite Element Method ◽  
Force Load ◽  
Mini Implants ◽  
Element Method

The aim of the study. Carry out a comparative analysis of the support ability of human jaw bone tissue in monocortical and bicortical installation of a mini-implant of own design OMG. Research methods. In order to study biomechanical characteristics of developed OMG mini-implant and bone tissue capacity during monocortical and bicortical installation, the finite element method (MSE) was used. The scheme and finite element 2-D model of bicortical installation of OMG mini-implant (length 8 mm, diameter 1.8 mm) provided full penetration through one layer of cortical bone equal to 1 mm, the entire cancellous bone and immersion in the second layer of cortical bone by 0, 5 mm. No implantation was immersed in the second cortical layer of bone during monocortical installation. A single force load of 1 N was applied in the horizontal direction parallel to the cortical plate of the bone. Results of the study. One of the most important factors leading to the success of the use of a mini-implant is its stability in the process of orthodontic treatment. Quite a high level of failure in the monocortical installation of mini-screws has led to the search for better methods to ensure the stability of their use. This was a bicortical method of fixation, based on the placement of the minig screw in the thickness of the two cortical plates of the jaws. Area for such installation of mini-screws can be a site of a palate and alveolar sprouts at installation of miniimplants through all its thickness. As shown by our data on the use of the finite element method under the force load of the biomechanical system "bone - mini-implant", the stress concentration zone is located in the area of the cortical bone of the jaw. The results of the calculation of the maximum stresses (σmax, MPa) and the maximum possible displacements (umax, mm) of the mini-implant in the biomechanical system "bone - mini-implant" in monocortical installation were, respectively, 8.27 MPa and 0.300 * 10-8 mm and in bicortical installation 6.00 MPa and 0.201 * 10-8 mm. The bicortical method of fixing the mini-implant in the jaw bones significantly increases the ability to resist deformation of this type of biomechanical system under force loads of the mini-implant. In the bicortical method of mini-implant placement, the extreme values of equivalent according to Mises stresses in the upper part of the cortical bone of the jaw are reduced by 27%. This can be explained by a significant increase in the area of contact due to the two layers of the cortical bone of the jaw with the surface of the mini-implant. Conclusion. The bicortical method of installing mini-implants is a more effective and reliable way to provide skeletal support during orthodontic treatment.

Experimental and numerical study on largely perforated steel shear plates with rectangular tube–shaped links

2020 ◽  
Vol 23 (15) ◽  
pp. 3307-3322 ◽  
Author(s):  
H Monsef Ahmadi ◽  
MR Sheidaii ◽  
H Boudaghi ◽  
G De Matteis
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Equivalent Plastic Strain ◽  
Absorption Capacity ◽  
Hysteretic Behavior ◽  
Steel Plate Shear Wall ◽  
Grid Systems ◽  
Finite Element Software ◽  
Internal Link ◽  
Rectangular Tube

Steel plate shear wall is one of the most effective dissipation systems which are commonly used in buildings. In order to improve the hysteretic behavior of shear panels, large perforation patterns may be applied, transforming the shear plate into a sort of grid systems, where plastic deformations are concentrated on specific internal link elements. This study investigates the behavior of grid systems loaded in shear where the internal links are created by cutting out internal parts, leaving rectangular tube–shaped link elements. The influence of internal link geometry on the cyclic performance of the systems is investigated experimentally. To this purpose, two specimens that varied in the width of links were fabricated and tested. The results indicate that any increase in the width of links leads to the growth of the ultimate strength, stiffness, and energy absorption capacity. Likewise, the stress distribution and fracture tendency of the tested specimens have been simulated by the finite element software (ABAQUS) and validated according to the experimental results. Based on finite element results, a suitable analytical formulation for the prediction of the shear strength at several shear deformation demands, considering the effect of thickness of the link, has been provided. Moreover, to improve the fracture tendency of the specimens, butterfly-shaped links, which varied in the middle length, were applied. The obtained results, which have been interpreted by considering the equivalent plastic strain value, prove that the shear panel behavior improves significantly when butterfly-shaped links are considered.

scholarly journals Finite Element Study on the Shear Capacity of Traditional Joints between Walls Made of AAC Masonry Units

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4035
Author(s):  
Marcin Kozłowski ◽  
Iwona Galman ◽  
Radosław Jasiński
Keyword(s):  
Finite Element ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Numerical Model ◽  
Fracture Energy ◽  
Shear Capacity ◽  
Nonlinear Behaviour ◽  
Structural Behaviour ◽  
Finite Element Software ◽  
Masonry Units

This paper presents the development of a numerical model aimed at the simulation of nonlinear behaviour of traditional joints between walls made of autoclaved aerated concrete (AAC) masonry units. Nonlinear behaviour and cracking of AAC and mortar were simulated using the concrete damaged plasticity (CDP) model available in the ABAQUS finite element software. The paper also presents and discusses the results of an experimental campaign involving testing six T-shaped, monosymmetric samples with traditional joints between walls loaded in shear. The results were used to validate the numerical model. The validation confirmed that the model is capable of producing accurate results and predicting the structural behaviour with a reasonably good accuracy in elastic and post-elastic stages. Furthermore, a sensitivity study was conducted, in which the variation of elastic modulus, Poisson’s ratio, tensile strength, compression strength and fracture energy of AAC was investigated. Results showed that the variation of elastic modulus, tensile strength and fracture energy is most critical to the structural behaviour of the model, while variation of the remaining parameters has a negligible effect on the results.

Numerical Study of Hydrodynamic Forces on a Submarine Piggyback Pipeline Under Wave Action

2012 ◽  
Author(s):  
Xiaofei Cheng ◽  
Yongxue Wang ◽  
Bing Ren ◽  
Guoyu Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Stokes Equations ◽  
Numerical Study ◽  
Hydrodynamic Forces ◽  
Wave Action ◽  
Numerical Results ◽  
Physical Model Test ◽  
Element Method

In the paper, a 2D numerical model is established to simulate the hydrodynamic forces on a submarine piggyback pipeline under regular wave action. The two-dimensional Reynolds-averaged Navier-Stokes equations with a κ-ω turbulence model closure are solved by using a three-step Taylor-Galerkin finite element method (FEM). A Computational Lagrangian-Eulerian Advection Remap Volume of Fluid (CLEAR-VOF) method is employed to simulate free surface problems, which is inherently compatible with unstructured meshes and finite element method. The numerical results of in-line force and lift (transverse) force on the piggyback pipeline for e/D = G/D = 0.25 and KC = 25.1 are compared with physical model test results, which are conducted in a marine environmental flume in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, China. It is indicated that the numerical results coincide with the experimental results and that the numerical model can be used to predict the hydrodynamic forces on the piggyback pipeline under wave action. Based on the numerical model, the surface pressure distribution and the motion of vortices around the piggyback pipeline for e/D = G/D = 0.25, KC = 25.1 are investigated, and a characteristic vortex pattern around the piggyback pipeline denoted “anti-phase-synchronized” pattern is recognized.

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