scholarly journals Effects of Loading Conditions on the Pelvic Fracture Biomechanism and Discrimination of Forensic Injury Manners of Impact and Run-Over Using the Finite Element Pelvic Model

2022 ◽  
Vol 12 (2) ◽  
pp. 604
Author(s):  
Zhengdong Li ◽  
Donghua Zou ◽  
Jianhua Zhang ◽  
Kaijun Ma ◽  
Yijiu Chen
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Pelvic Fracture ◽  
Effective Strain ◽  
Forensic Identification ◽  
Side Impact ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Simulation Performance ◽  
Forensic Practice

This study aimed to systematically simulate the responses of pelvic fracture under impact and run-over to clarify the effects of boundary and loading conditions on the pelvic fracture mechanism and provide complementary quantitative evidence for forensic practice. Based on the THUMS finite element model, we have validated the simulation performance of the model by a real postmortem human pelvis side impact experiment. A total of 54 simulations with two injury manners (impact and run-over), seven loading directions (0°, 30°, 60°, 90°, 270°, 300°, 330°), and six loading velocities (10, 20, 30, 40, 50, and 60 km/h) were conducted. Criteria of effective strain, Von-Mises stress, contact force, and self-designed normalized eccentricity were used to evaluate the biomechanism of pelvic fracture. Based on our simulation results, it’s challenging to distinguish impact from run-over only rely on certain characteristic fractures. Loads on the front and back were less likely to cause pelvic fractures. In the 30°, 60°, 300° load directions, the overall deformation caused a “diagonal” pelvic fracture. The higher is the velocity (kinetic energy), the more severe is the pelvic fracture. The contact force will predict the risk of fracture. In addition, our self-designed eccentricity will distinguish the injury manner of impact and run-over under the 90° loads. The “biomechanical fingerprints” based on logistic regression of all biomechanical variables have an AUC of 0.941 in discriminating the injury manners. Our study may provide simulation evidence and new methods for the forensic community to improve the forensic identification ability of injury manners.

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

scholarly journals Stress and Factor of Safety for Connecting Rod using Ansys

2019 ◽  
Vol 8 (6) ◽  
pp. 3463-3466
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Factor Of Safety ◽  
Stress Test ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Connecting Rod ◽  
Element Analysis ◽  
Ic Engine ◽  
Von Mises

The primary link of an IC engine is a connecting rod. Its position is in-between the crankshaft and the piston whose key function is to convert the piston motion which is reciprocating in nature into rotary motion of the crank by transmitting the piston thrust to the crankshaft. This has entailed performing a detailed load analysis. In this paper, connecting rod's finite element analysis was done using Finite Element techniques. So firstly by using the schematic diagram the solid model of the connecting rod was created using Solid works software. Then using the Ansys R17.1 software the meshing was done and then the Finite element analysis is done to find the Equivalent (Von-Mises) stresses and the Factor of Safety under the loading conditions. Structural Steel is the material which is used for connecting rod and the loading conditions are assumed to be static. In Equivalent (Von-Mises) stress test maximum stress is found to be 1.504x108 Pa and the minimum factor of safety is 1.20765 for the connecting rod

Finite Element Simulation of the Nosing Process of Metal Tubes with a Conical Die

2011 ◽  
Vol 704-705 ◽  
pp. 1444-1450
Author(s):  
Liang Chu ◽  
Li Jun Shi ◽  
Yan Bi ◽  
Da Sen Bi
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Von Mises Stress ◽  
Thickness Variation ◽  
Metal Tube ◽  
The Finite Element Method ◽  
Element Simulation ◽  
Conical Die ◽  
Von Mises ◽  
Tube Nosing

In this paper, the nosing process of metal tube with a conical die is investigated using the finite element method, and a series of simulations on the tube nosing process by using the program ABAQUS is carried out. The concrete process of tube nosing deformation is described. Some simulation results on tube nosing deformation such as the distributions of the Von Mises stress and effective strain, the material thickness variation of deformation zone are obtained and analyzed.

3D Finite Element Stress Analysis of an Implant Supported Overdenture Under Bruxism and Lingualized Loading Conditions

2015 ◽  
Author(s):  
Md Abu Hasan ◽  
Panos S. Shiakolas
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Loading Condition ◽  
Alveolar Bone ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Long Term Effects ◽  
Element Analysis ◽  
Implant Complications

Bruxism is a nonfunctional motor activity that is characterized by grinding and clenching of the teeth. It has been postulated that bruxism causes excessive occlusal load on the dental implant and its superstructures leading to biological and biomechanical complications. While many researchers suggest that grinding/clenching causes early implant complications and accelerated bone loss, others indicate that the long term effects are still unclear. The goal of this study is to analyze the effect of bruxism loading condition on the stress distribution of an implant supported overdenture (ISO) using finite element analysis (FEA) and compare the results with one of the most functionally efficient occlusion schemes in the clinical dentistry — lingualized occlusion. A high fidelity solid model of a mandibular denture encompassing lingual and buccal cusps, mesial and distal fossae supported by four implants and a connecting titanium prosthetic bar, resting on alveolar bone were modeled in SolidWorks 2013 following proper clinical guidelines and imported to ANSYS 15.0 for stress analysis. The results of the study demonstrate that the stress distribution in the implant prostheses and surrounding bone is significantly affected due to bruxism as compared to the lingualized loading. While the location of the maximum stress concentration was the same (neck of the posterior implants) for both loading conditions, there was an increase of approximately 115% von-Mises stress for bruxism loading condition as compared to the lingualized occlusion. The maximum principal stress in the cortical bone surpassed the ultimate tensile strength limit of the jaw bone implying possibility of bone resorption in the peri-implant area.

FINITE ELEMENT ANALYSIS OF THE HUMAN HEAD UNDER SIDE CAR CRASH IMPACTS AT DIFFERENT SPEEDS

2014 ◽  
Vol 14 (06) ◽  
pp. 1440002 ◽  
Author(s):  
XINGQIAO DENG ◽  
SHOU AN CHEN ◽  
R. PRABHU ◽  
YUANYUAN JIANG ◽  
Y. MAO ◽  
...  
Keyword(s):  
Finite Element ◽  
Brain Injuries ◽  
Head Injuries ◽  
Human Head ◽  
Side Impact ◽  
Von Mises Stress ◽  
Head Model ◽  
Car Crash ◽  
Von Mises ◽  
The Impact

Mechanical response of the human head under a side car crash impact is crucial for modeling traumatic brain injuries (TBI) or concussions. The current advances in computational methods and the finite element models of the human head provide a significant opportunity for biomechanical study of brain injuries; however, limited experimental data is available for delineating the injury relationship between the head injury criteria (HIC) and the tensile pressure or von Mises stress. In this research, we assess human head injuries in a side impact car crash using finite element (FE) simulations that quantify the tensile pressures and maximum strain profiles. In doing so, five FE analyses for the human head have been carried out to investigate the correlations between the HIC measured in the dummy model at different moving deformable barrier (MDB) velocities increasing from 10 mph to 30 mph in 5 mph increments and the pressure and von Mises stress of the skull, the skin, the cerebral spinal fluid (CSF) and the brain. The computational simulation results for the tensile pressures and von Mises stresses correlated well with the HIC15 and peak accelerations. Also a second-order polynomial seemed to fit the stress levels to the impact speeds and as such the presented method for using FE human head analysis could be used for reconstruction of head impacts in different side car crash conditions; furthermore, the head model would provide a tool for investigation of the cause and mechanisms of head injuries once the type and locations of injuries are quantified.

Influence of Implant Positions and Occlusal Forces on Peri-Implant Bone Stress in Mandibular Two-Implant Overdentures: A 3-Dimensional Finite Element Analysis

2017 ◽  
Vol 43 (6) ◽  
pp. 419-428 ◽  
Author(s):  
Angel Alvarez-Arenal ◽  
Ignacio Gonzalez-Gonzalez ◽  
Hector deLlanos-Lanchares ◽  
Aritza Brizuela-Velasco ◽  
Elena Martin-Fernandez. DDS ◽  
...  
Keyword(s):  
Finite Element ◽  
Von Mises Stress ◽  
Application Site ◽  
Loading Conditions ◽  
Element Analysis ◽  
3 Dimensional ◽  
Bone Stress ◽  
Dimensional Finite Element ◽  
Implant Overdenture ◽  
Von Mises

The aim of this study was to evaluate and compare the bone stress around implants in mandibular 2-implant overdentures depending on the implant location and different loading conditions. Four 3-dimensional finite element models simulating a mandibular 2-implant overdenture and a Locator attachment system were designed. The implants were located at the lateral incisor, canine, second premolar, and crossed-implant levels. A 150 N unilateral and bilateral vertical load of different location was applied, as was 40 N when combined with midline load. Data for von Mises stress were produced numerically, color coded, and compared between the models for peri-implant bone and loading conditions. With unilateral loading, in all 4 models much higher peri-implant bone stress values were recorded on the load side compared with the no-load side, while with bilateral occlusal loading, the stress distribution was similar on both sides. In all models, the posterior unilateral load showed the highest stress, which decreased as the load was applied more mesially. In general, the best biomechanical environment in the peri-implant bone was found in the model with implants at premolar level. In the crossed-implant model, the load side greatly altered the biomechanical environment. Overall, the overdenture with implants at second premolar level should be the chosen design, regardless of where the load is applied. The occlusal loading application site influences the bone stress around the implant. Bilateral occlusal loading distributes the peri-implant bone stress symmetrically, while unilateral loading increases it greatly on the load side, no matter where the implants are located.

scholarly journals Arthroscopic Suture Anchor Design Finite Element Study

2021 ◽  
Vol 9 (A) ◽  
pp. 562-566
Author(s):  
Mai Ayoub ◽  
Mohamed EL-Anwar ◽  
Mazen I. Negm
Keyword(s):  
Finite Element ◽  
Cortical Bone ◽  
Suture Anchor ◽  
Von Mises Stress ◽  
Design Parameters ◽  
Loading Conditions ◽  
Suture Anchors ◽  
Element Analysis ◽  
Thread Profile

AIM: This in-vitro study investigated arthroscopic suture anchors’ main design parameters effect on surrounding bone. METHODS: Thirty-dimensional arthroscopic suture anchor designs’ models were created on engineering CAD software by changing thread profile, pitch, and anchor tip profile as design parameters. These models were imported into ANSYS Workbench for finite element analysis. Bone was simplified and modeled as two coaxial cylinders. Tensile vertical load of 300 N, and oblique at 45º to the vertical axis, were applied to each model as two loading conditions while the simplified bone base was fixed in place as a boundary condition. RESULTS: The finite element analyses on all models under both loading conditions showed stresses within physiological limits on bone. Trapezoidal teeth and inclined cut teeth designs showed the lowest values of stresses and deformations respectively on the bone under oblique loads, while curved tooth and square tooth designs showed the lowest values of stresses and deformations respectively on the bone under vertical loads. General ascending or descending trend was recorded by increasing pitch from 1.2 to 1.5 to 1.8 mm on the total deformation and maximum Von Mises stress on bone and anchor body. Tapered tip slightly increased bone and anchor stresses. CONCLUSION: Arthroscopic anchors thread profile has minor affect on cortical bone behavior. Trapezoidal teeth, square tooth, and inclined cut teeth profiles showed the lowest values of stresses and deformations on cortical bone. Increasing thread pitch of arthroscopic suture anchors increases or decreases stress on the bone, and anchor body according to thread profile edges. Anchor tip profile negligibly affects both deformations and stresses on bone and anchor body.

scholarly journals Effects on the Various Aluminum Foam Fenders of a Tripod Offshore Wind Turbine Collision Due to a Ship

2020 ◽  
Vol 54 (1) ◽  
pp. 79-96
Author(s):  
Zhiwei Han ◽  
Xinlei Zhao ◽  
Chun Li ◽  
Qinwei Ding
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Dynamic Response ◽  
Contact Force ◽  
Aluminum Foam ◽  
Offshore Wind ◽  
Von Mises Stress ◽  
Offshore Wind Turbine ◽  
Structural Dynamic ◽  
Von Mises

AbstractThe interest in offshore wind energy is growing all over the world. Increasingly, offshore wind turbines (OWTs) are being installed close to shipping lanes, which puts them at risk of potential collisions with ships during their service period. This article aims to investigate the structural dynamic response of OWTs to a ship collision. Considering the structure size of the fender as well as the nonlinear characteristics of the structural materials, a finite element model of a 5,000-ton ship colliding with a 4-MW tripod OWT has been developed using the explicit finite element code LS-DYNA. By observing the collision energy conversion, contact force, fender performance, Von Mises stress on the tripod, shear stress, and dynamic response of a nacelle in differently sized fender collision scenarios, it was observed that when the thickness of the fender surpasses 1.1 m, it can protect the OWT from a collision more effectively than with no fender case. Otherwise, the local contact force is cushioned by aluminum foam materials, whose contact force leads to a whole movement of the bearing tripod. The tripod with the aforementioned 1.1-m fender generates a contact force, Von Mises stress, and a shear stress, as well as the anticollision characteristics of a fender and the dynamic responses of a nacelle in 15 scenarios. Therefore, the structural design of the fender is essential in the safety of a tripod foundation in a collision. This article will provide a better understanding of the collision characteristics of the fender in the future.

Numerical Simulation and Analysis on Bending Forming of Hull Plate

2011 ◽  
Vol 704-705 ◽  
pp. 1451-1457
Author(s):  
Lin Lin Luo ◽  
Da Sen Bi ◽  
Yan Bi ◽  
Liang Chu ◽  
Xu Ma ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Deformation Zone ◽  
Effective Strain ◽  
Von Mises Stress ◽  
Finite Element Software ◽  
Bending Process ◽  
Simulation Results ◽  
Von Mises

Bending process is one of the important methods to form thick hull plate, whose accuracy is directly related to the quality of hull plate forming.In this paper, bending process of thick hull plate is simulated by using finite element software ANSYS, and some simulation results on bending deformation of thick hull plate such as the deformation of meshes in deformation zone, the distributions of the Von Mises stress and effective strain are obtained.

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