DYNAMIC RESPONSE OF PELVIC COMPLEX FINITE ELEMENT STUDY AND VALIDATION UNDER SIDE IMPACT

2017 ◽  
Vol 17 (07) ◽  
pp. 1740036 ◽  
Author(s):  
AILI QU ◽  
DONGMEI WANG ◽  
XIANGSEN ZENG ◽  
QIU’GEN WANG
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Pelvic Ring ◽  
Element Model ◽  
Hemodynamic Instability ◽  
Complex Model ◽  
Side Impact ◽  
Lateral Impact ◽  
The Impact

Objective: To investigate and validate dynamic response of the pelvis, a finite element model of seated pelvic complex comprising of bone, ligaments, abdominal artery and soft tissue was developed and concurrently, a cadaver experiment was set up. Materials and Methods: Based on supine scanned CT images, we first developed an FE pelvic complex model and modified it to construct a seated pelvic model by anteriorly rotating the proximal femur to 90[Formula: see text]. For the cadaver experiment, a customized pelvic impact apparatus was designed and optical devices, strain gauges and pressure detectors were used to measure the pelvic response. Results: The results of the FE analysis and the cadaver tests were congruent in terms of impact force and fracture sites. Dynamic arterial response to the lateral impact showed hemodynamic instability that was displayed in pressure variation. The response of ligaments indicated that the posterior ligaments of pelvic ring experienced a larger amount of load. Conclusion: FE results provided the impact of ligaments and arteries besides impact force, compression (C) and viscous criterion (VC). Accordingly, the cadaver experiment measured arterial pressure, impact force, bone strain and compression. The compatibility between the FE and cadaver analyses demonstrates the high bio-fidelity of our pelvic complex model.

Development of a Finite Element Model of the Human Shoulder

1999 ◽  
Author(s):  
Masami Iwamoto ◽  
Kazuo Miki ◽  
Babushankar Sambamoorthy ◽  
King H. Yang ◽  
Albert I. King
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Numerical Models ◽  
Element Model ◽  
Injury Mechanism ◽  
Side Impact ◽  
Human Anatomy ◽  
Lateral Impact ◽  
Crash Dummies ◽  
The Impact

Abstract During an automotive side impact, the shoulder is likely to be the first body part that is directly impacted either by the internal structures of the vehicle or by the side airbag. Therefore, a good understanding of the injury mechanism and the kinematics of the shoulder is critical for occupant protection in side impact. Existing side impact crash dummies do not have structures that are capable of reproducing the kinematics and kinetics of a human occupant. Over the past several years, many numerical models have been developed from head to foot in an attempt to overcome the shortcomings of these crash dummies. However, relatively few attempts have been made to include the shoulder. The purpose of this study is to develop a finite element model of the human shoulder in order to achieve a deeper understanding of the injury mechanism and the kinematics of the shoulder in side impacts. Basic anthropometric data used to develop the skeletal portion of the shoulder model were taken from a commercial data package of the human shoulder geometry (Viewpoint Datalabs). This geometry was scaled to fit a 50th percentile male occupant according to the data reported by Schneider et al. (1983). The shoulder model included the three bones of the shoulder, namely the humerus, scapula and clavicle. Each bone was modeled in two parts. The spongy bone was modeled using crushable solids and the cortical bone was modeled using damageable shell elements. The model also includes major ligaments, which form the acromioclavicular and sternoclavicular articulations. The deltoid muscle, which was modeled by crushable solids in order to absorb part of the impact energy, was added to this model for lateral impact simulations. This shoulder model was then integrated with a human thorax model developed by Wang (1995), along with other preexisting models of other parts of the human anatomy. Material properties for the model were taken from the literature. Experimental data obtained from lateral impact sled tests of 17 cadavers conducted at Wayne State University were used to validate the model. Impact forces in four regions, specifically, the shoulder, thorax, abdomen and pelvis, were calculated by the model and were compared with forces obtained experimentally from rigid wall impacts at 6.7m/s and padded wall impacts at 8.9m/s.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 327-331 ◽  
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Impact Force ◽  
Impact Load ◽  
Residual Deformation ◽  
Time History ◽  
Single Layer ◽  
Element Analysis ◽  
Deformation Stage ◽  
The Impact

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

DEVELOPMENT AND BIOFIDELITY EVALUATION OF AN OCCUPANT BIOMECHANICAL MODEL OF A CHINESE 50TH PERCENTILE MALE FOR SIDE IMPACT

2017 ◽  
Vol 17 (07) ◽  
pp. 1740039 ◽  
Author(s):  
ZHENGWEI MA ◽  
LELE JING ◽  
FENGCHONG LAN ◽  
JINLUN WANG ◽  
JIQING CHEN
Keyword(s):  
Finite Element ◽  
Human Body ◽  
Computational Models ◽  
Rating Scale ◽  
Element Model ◽  
Side Impact ◽  
Body Parts ◽  
Lateral Impact ◽  
Human Body Model ◽  
Body Model

Finite element modeling has played a significant role in the study of human body biomechanical responses and injury mechanisms during vehicle impacts. However, there are very few reports on similar studies conducted in China for the Chinese population. In this study, a high-precision human body finite element model of the Chinese 50th percentile male was developed. The anatomical structures and mechanical characteristics of real human body were replicated as precise as possible. In order to analyze the model’s biofidelity in side-impact injury prediction, a global technical standard, ISO/TR 9790, was used that specifically assesses the lateral impact biofidelity of anthropomorphic test devices (ATDs) and computational models. A series of model simulations, focusing on different body parts, were carried out against the tests outlined in ISO/TR 9790. Then, the biofidelity ratings of the full human body model and different body parts were evaluated using the ISO/TR 9790 rating method. In a 0–10 rating scale, the resulting rating for the full human body model developed is 8.57, which means a good biofidelity. As to different body parts, the biofidelity ratings of the head and shoulder are excellent, while those of the neck, thorax, abdomen and pelvis are good. The resulting ratings indicate that the human body model developed in this study is capable of investigating the side-impact responses of and injuries to occupants’ different body parts. In addition, the rating of the model was compared with those of the other human body finite element models and several side-impact dummy models. This allows us to assess the robustness of our model and to identify necessary improvements.

Study of Ship-Ice Collision on Ice Breaker ARAON

2014 ◽  
Author(s):  
Sungchan Kim ◽  
Insik Nho ◽  
Takkee Lee ◽  
Kyungsik Choi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Force ◽  
Structural Response ◽  
Element Model ◽  
Design Data ◽  
Complex Process ◽  
The Impact ◽  
Interaction Behaviors ◽  
Ship Speed

The interaction between a ship and sea ice is a complex process depending on the ice properties, the ice geometry and the relative velocity between the ship and the ice. The effect of important parameters such as ship speed and ice thickness on the impact force are studied by means of finite element model. Idealized ice element types are applied to finite element model in order to survey the impact force and the structural response of icebreaker ARAON subjected to sea ices. Interaction behaviors obtained by finite element model considering the varying parameters are also discussed to compare the numerical results with the design data of ARAON.

scholarly journals Dynamic characteristics of mistuned bladed disk system under rub-impact force

2020 ◽  
Vol 12 (11) ◽  
pp. 168781402097306
Author(s):  
Hui Zhang ◽  
Tianyu Zhao ◽  
Hongyuan Zhang ◽  
Honggang Pan ◽  
Huiqun Yuan
Keyword(s):  
Finite Element ◽  
Variable Thickness ◽  
Impact Force ◽  
Element Model ◽  
Force Model ◽  
Disk System ◽  
Element Analysis ◽  
Bladed Disk ◽  
Blade Tip ◽  
The Impact

In order to study the rubbing of the mistuned bladed disk system with variable thickness blades, an elastically supported shaft-variable thickness blades coupled finite element model is established in this paper. A new rubbing force model is proposed considering the variable thickness section characteristics and rotation effect of the variable thickness blade. A method of mistuned parameter identification is introduced which consists of static frequency testing of blades, dichotomy, and finite element analysis. Based on the finite element method, the mistuned bladed disk system is made dynamic analysis in full rubbing by applying the judgment load method. The dynamic response of the mistuned bladed disk system is discussed under different conditions. The results show that increasing the amount of mistuning will increase the system vibration. At high speeds, the impact force will be partially offset by centrifugal force. And the rubbing gap affects the form of rubbing. With the gap decreases, the system will change from intermittent rubbing to continuous rubbing. In addition, when the system is rubbed, due to energy dissipation and blade damping, the stress is transferred from the blade tip to the blade root and attenuated. In general, rubbing is a random complex nonlinear vibration process.

Finite Element Modelling of a Generic Rotor-Bearing System and Experimental Validation

2015 ◽  
Author(s):  
A. Rehman ◽  
K. S. Ahmed ◽  
F. A. Umrani ◽  
B. Munir ◽  
A. Mehboob ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Element Model ◽  
Mode Shapes ◽  
Efficient Operation ◽  
Critical Speeds ◽  
Rotor Bearing ◽  
The Impact ◽  
Bearing System

The design and development of the rotating machinery require a precise identification of its dynamic response for efficient operation and failure prevention. Determination of critical speeds and mode shapes is crucial in this regard. In this paper, a finite element model (FEM) based on the Euler beam theory is developed for investigating the dynamic behavior of flexible rotors. In-house code in Scilab environment, an open source platform, is developed to solve the matrix equation of motion of the rotor-bearing system. The finite element model is validated by the impact hammer test and the dynamic testing performed on the rotors supported on a purpose-built experimental setup. Bearing stiffness is approximated by using the Hertzian contact theory. Obtaining the critical speeds and mode shapes further improves the understanding of dynamic response of rotors. This study paves way towards advanced research in rotordynamics in Faculty of Mechanical Engineering, GIK Institute.

Sensitivity Study of Boundary Conditions for a 9-Meter Drop of a Shielded Cask for Operational Handling of a Container of Liquid

2016 ◽  
Author(s):  
Michael C. Yaksh ◽  
Suresh Babu
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Boundary Conditions ◽  
Pressure Vessel ◽  
Element Model ◽  
Computer Code ◽  
Sensitivity Study ◽  
Confined Space ◽  
Explicit Finite Element ◽  
The Impact

A shielded cask is used to move welded containers whose contents are liquid. The requirement controlling the design of the shielded cask was the 9-meter drop. Since the orientation of the cask is arbitrary, it is required to assume an orientation which would result in the most damage to the cask. For such drops the target is usually considered to be an unyielding surface. The shielded cask of interest is not designed with components to mitigate the damage due to such drops. The shielded cask contains a thick shell of lead which is considered to move and deform during the 9-meter drop. Additionally, the container of liquid is not physically attached to the cask, and is free to move within the confined space during the event as well. Each component has its own unique stiffness and mass characteristics which could result in a different dynamic response. Since the dynamic response of each component is different, the most damage to a particular component may be sensitive to the boundary conditions. The unyielding surface would maximize the damage to the impact surface of the cask, but as a result, could mitigate the maximum loading applied to other components of the cask. Most actual targets are comprised of concrete. The evaluations are performed using an explicit finite element computer code. Consequently, it is necessary to monitor certain energies, such as the hourglass energy or a sliding energy indicating the behavior of the contact surface associated with the target. These parameters confirm the accurate behavior of the elements comprising the finite element model. Given that components can have a different response, the hourglass energy may also vary. Varying the boundary conditions will affect these types of parameters. In this paper, the authors present the results of a study of the effect of the boundary conditions on the shielded cask components response to the 9-meter drop. The primary orientation of interest is the end drop. The end drop maximizes the axial loading to the container. It is this orientation which could result in the most compression of the lead shield leading to increased radiation exposure. The container is considered as a pressure vessel and its integrity would be evaluated using the plastic strain based criteria contained in Section III, Division 3. The shielded cask, however, is not a pressure vessel and was evaluated using Section VIII, Division 2, Part 5. Both evaluations used the plastic strains and triaxiality factors determined from the drop evaluations.

Study on Concrete Filled Square Steel Tube under Lateral Impact Loading

2010 ◽  
Vol 163-167 ◽  
pp. 941-946
Author(s):  
Liang Zheng ◽  
Zhi Hua Chen
Keyword(s):  
Dynamic Response ◽  
Impact Force ◽  
Residual Deformation ◽  
Time History ◽  
Steel Tube ◽  
Lateral Impact ◽  
Deformation Stage ◽  
Elastic Rebound ◽  
Square Steel Tube ◽  
The Impact

Finite element models of both the concrete filled square steel tube and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. Three stages of time history curve of the impact force of the concrete filled square steel tube including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. And with the wall thickness increased, the peak of the impact force and the platform value is also increase, with axial force increased, the peak impact force hardly changed, but the impact platform value have a certain extent lower. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of the impact of the concrete filled square steel tube based on numerical analysis, four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation. Finally, time history curve of the impact force and displacement according to the dynamic response is analyzed under the impact of the corner of the concrete filled square steel tube, the results show that the anti-impact capability of 45 degree angle is higher than that of the front impact.

Numerical analysis of collision between a tractor-trailer and bridge pier

2018 ◽  
Vol 9 (4) ◽  
pp. 484-503 ◽  
Author(s):  
Luwei Chen ◽  
Hao Wu ◽  
Qin Fang ◽  
Tao Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Force ◽  
Element Model ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Highway Bridge ◽  
Heavy Duty ◽  
The Impact ◽  
The Finite Element Model

Accidents involving collisions of heavy-duty trucks with highway bridge piers occurred occasionally, in which the bridge piers might be subjected to severe damage, and cause the collapse of the superstructure due to the loss of axial loading capacity. The existing researches are mostly concentrated on the light- or medium-duty trucks. This article mainly concerns about the collisions between the heavy-duty trucks (e.g. tractor-trailer) and bridge piers as well as the evaluation of the impact force. First, by modifying the finite element model of Ford F800 single-unit truck, which was developed by National Crash Analysis Center, the finite element model of a tractor-trailer is established. Then, the full-scale tractor-trailer crash test on concrete-filled steel pier jointly conducted by Texas Transportation Institute, Federal Highway Administration, and Texas Department of Transportation is numerically simulated. The impact process is well reproduced and the established model is validated by comparison of the impact force. It indicates that the tractor-trailer impact force time history consists of two or three peaks and the corresponding causes are revealed. Furthermore, the parametric influences on the impact force are discussed, including the diameter and cross section shape of the pier, cargo weight, impact velocity, relative impact position, and vehicle type. Finally, the finite element model of an actual reinforced concrete highway bridge pier is established, and the impact force and lateral displacement of the pier subjected to the impact of the tractor-trailer are numerically derived and discussed.

The Impact of an Open-Book Pelvic Ring Injury on Bone Strain: Validation of a Finite Element Model and Analysis Within the Gait Cycle

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Zoryana Salo ◽  
Hans Kreder ◽  
Cari Marisa Whyne
Keyword(s):  
Finite Element ◽  
Gait Cycle ◽  
Pelvic Ring ◽  
Element Model ◽  
Heel Strike ◽  
Fe Model ◽  
Open Book ◽  
Pubic Ramus ◽  
Biomechanical Behavior ◽  
The Impact

Abstract The threshold for surgical stabilization for an open-book pelvic fracture is not well defined. The purpose of this research was to validate the biomechanical behavior of a specimen-specific pelvic finite element (FE) model with an open-book fracture with the biomechanical behavior of a cadaveric pelvis in double leg stance configuration under physiologic loading, and to utilize the validated model to compare open book versus intact strain patterns during gait. A cadaveric pelvis was experimentally tested under compressive loading in double leg stance, intact, and with a simulated open-book fracture. An intact FE model of this specimen was reanalyzed with an equivalent simulated open-book fracture. Comparison of the FE generated and experimentally measured strains yielded an R2 value of 0.92 for the open-book fracture configuration. Strain patterns in the intact and fractured models were compared throughout the gait cycle. In double leg stance and heel-strike/heel-off models, tensile strains decreased, especially in the pubic ramus contralateral to the injury, and compressive strains increased in the sacroiliac region of the injured side. In the midstance/midswing gait configuration, higher tensile and compressive FE strains were observed on the midstance side of the fractured versus intact model and decreased along the superior and inferior pubic rami and ischium, with midswing side strains reduced almost to zero in the fractured model. Identified in silico patterns align with clinical understanding of open-book fracture pathology suggesting future potential of FE models to quantify instability and optimize fixation strategies.

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