Stress Analysis of the Lumbar Spine Using the Finite Element Model

1995 ◽  
pp. 167-173 ◽  
Author(s):  
Yoshishige Arai ◽  
Hideaki E. Takahashi ◽  
Hiroyuki Suzuki
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Stress Analysis ◽  
Element Model ◽  
The Finite Element Model

scholarly journals The Finite Element Model of Seated Whole Human Body for Vibration Investigations of Lumbar Spine in Complex System

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 125046-125055
Author(s):  
Rui-Chun Dong ◽  
Qian-Jian Guo ◽  
Wei Yuan ◽  
Wei Du ◽  
Xian-Hai Yang ◽  
...  
Keyword(s):  
Complex System ◽  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Human Body ◽  
Element Model ◽  
The Finite Element Model

Stress analysis of shielding electrode in chip with pressure sensor embedded in accelerometer

2019 ◽  
Vol 36 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Chun-Lin Lu ◽  
Meng-Kao Yeh
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Model ◽  
Stress Analysis ◽  
Glass Substrate ◽  
Pressure Sensors ◽  
Element Model ◽  
Content Type ◽  
Out Of Plane ◽  
The Finite Element Model

Purpose Analysis of the thermal effects during the packaging process or in the actual operating environment is necessary to develop small monolithic integrated sensing chips with heterogeneous integration. The use of multiple layers and various materials in monolithic integrated sensing chips addresses the coefficient of thermal expansion (CTE) mismatch issue. The purpose of this study is to focus on the residual stress analysis of the shielding electrode, which is a metal film that prevents pull-in of proof-mass during anodic bonding in microelectromechanical system (MEMS) chips with pressure sensors embedded in an accelerometer. Design/methodology/approach The finite element model of the chip was built by the commercial software ANSYS, and the residual stress was evaluated during the die attachment process for the shielding electrode. Various shielding electrode materials and a proposed design with a keep-out zone to reduce the residual stress are discussed, with a focus on the relationship between the geometric parameters of the chip and the residual stress for copper shielding electrodes of different thicknesses. Findings The results of the finite element analysis showed that the use of polysilicon as a shielding electrode in the proposed design generated the lowest residual stress because of its low CTE. The maximum stresses in both of in-plane and out-of-plane directions in the finite element model were reduced by keep-out zone design for the proposed design of the copper shielding electrode, and had 11 times reduction in out-of-plane direction especially, according to the nonlinear analysis as the stress concentration point in the shielding electrode moved. Moreover, the design with a thinner shielding electrode, thinner glass substrate and higher CTE of the glass substrate also lowered the maximum von Mises stress. On the other hand, the stress level during the operating temperature, without considering residual stress, overestimated up to five times in the proposed design. Originality/value In this study, valuable suggestions are proposed for the design of chips with pressure sensors embedded in accelerometers.

Validation of an In Vivo Medical Image-Based Young Human Lumbar Spine Finite Element Model

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Matthew J. Mills ◽  
Nesrin Sarigul-Klijn
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Medical Image ◽  
Female Subject ◽  
Element Model ◽  
Young Female ◽  
Lumbosacral Spine ◽  
Finite Element Models ◽  
The Finite Element Model

Mathematical models of the human spine can be used to investigate spinal biomechanics without the difficulties, limitations, and ethical concerns associated with physical experimentation. Validation of such models is necessary to ensure that the modeled system behavior accurately represents the physics of the actual system. The goal of this work was to validate a medical image-based nonlinear lumbosacral spine finite element model of a healthy 20-yr-old female subject under physiological moments. Range of motion (ROM), facet joint forces (FJF), and intradiscal pressure (IDP) were compared with experimental values and validated finite element models from the literature. The finite element model presented in this work was in good agreement with published experimental studies and finite element models under pure moments. For applied moments of 7.5 N·m, the ROM in flexion–extension, axial rotation, and lateral bending were 39 deg, 16 deg, and 28 deg, respectively. Excellent agreement was observed between the finite element model and experimental data for IDP under pure compressive loading. The predicted FJFs were lower than those of the experimental results and validated finite element models for extension and torsion, likely due to the nondegenerate properties chosen for the intervertebral disks and morphology of the young female spine. This work is the first to validate a computational lumbar spine model of a young female subject. This model will serve as a valuable tool for predicting orthopedic spinal injuries, studying the effect of intervertebral disk replacements using advanced biomaterials, and investigating soft tissue degeneration.

Stress Analysis of the Pressurized-Water Reactor Control Rod Under Operating Conditions

2020 ◽  
Author(s):  
Leo A. Carrilho
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Finite Element Model ◽  
Stress Analysis ◽  
Maximum Stress ◽  
Element Model ◽  
Operating Conditions ◽  
Pressurized Water ◽  
Control Rod ◽  
The Finite Element Model

Abstract This work aims to develop a finite element model of a PWR control rod at operating conditions for stress analysis of the rod cladding. The finite element model simulates a control rod exposed to high operating temperatures and pressure while portions of the rod are irradiated, resulting in accumulated fluence of neutrons by the rod materials. These high temperature and accumulated fluence induce thermal expansion and swelling of the rod materials, especially of the absorber, which may eventually interact with the rod cladding, generating stresses and strains in the wall of the cladding tube. Moreover, if the maximum stress or strain in the tube wall exceeds the design allowable limit, the absorber rod is considered failed. The author creates the control rod finite element model and apply the operating loads on two-dimensional axisymmetric elements to obtain displacements, temperatures, stresses, and strains. The model also includes contact surface elements to evaluate eventual mechanical interactions between absorber and cladding due to thermal expansion and swelling effects. This is a coupled nonlinear static analysis solution that includes thermal expansion effects to calculate temperature distribution and subsequent thermal strains in the absorber rod due to the heat generation rates and coolant temperature; swelling analysis to calculate absorber growth induced by irradiation; and creep analysis to calculate absorber stress relaxation under coolant pressure and temperature. The finite element model is capable of determining whether or not absorber-to-cladding gap closure will occur and if so, calculate maximum stress and strain in the rod cladding associated with mechanical interaction between the two components induced by the operating temperature and thermal fluence loads.

Validation efforts and flexibilities of an eight-year-old human juvenile lumbar spine using a three‐dimensional finite element model

2010 ◽  
Vol 48 (12) ◽  
pp. 1223-1231 ◽  
Author(s):  
D. Davidson Jebaseelan ◽  
Chidambaram Jebaraj ◽  
Narayan Yoganandan ◽  
S. Rajasekaran
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

scholarly journals Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Structural Parameters ◽  
Element Model ◽  
Structural Behavior ◽  
Model Tuning ◽  
The Finite Element Model ◽  
Cable Stayed Bridges

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

Biodynamics of Human Thorax With Body Armors Subject to Bullet Impact

2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Body Armor ◽  
Projectile Impact ◽  
Human Thorax ◽  
Trachea And Bronchi ◽  
Armor System ◽  
The Finite Element Model

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.

Dynamic Analysis of a Turbocharger Centrifugal Compressor Impeller

1991 ◽  
Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Centrifugal Compressor ◽  
Element Model ◽  
Simplified Model ◽  
Cyclic Symmetry ◽  
Compressor Impeller ◽  
Cyclic Symmetric ◽  
The Finite Element Model

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.

Analysis of Effective Pre-Stress of Continuous Rigid Frame Bridge in Service Based on Inversion Theory

2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Inversion Method ◽  
Vertical Deflection ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Inversion Theory ◽  
Rigid Frame Bridge ◽  
The Finite Element Model

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.

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