Action of human respiratory muscles inferred from finite element analysis of rib cage

1992 ◽  
Vol 72 (4) ◽  
pp. 1461-1465 ◽  
Author(s):  
S. H. Loring
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Geometric Analysis ◽  
Respiratory Muscles ◽  
Canine Model ◽  
Three Dimensions ◽  
Human Model ◽  
Transverse Diameter ◽  
Element Analysis ◽  
Rib Cage

The actions of several human respiratory muscles have been inferred from finite element analysis of the rib cage. The human model is based on anatomic and mechanical measurements in dogs and human cadavers. As in an earlier canine model, the external and internal (interosseous) intercostal muscles were found to cause, respectively, inspiratory and expiratory displacements of the rib cage, in agreement with the two-dimensional geometric analysis of Hamberger. When extended to three dimensions, Hamberger's analysis helps explain why muscles at the side of the rib cage produce changes in the anteroposterior diameter, whereas muscles at the front and back of the rib cage cause changes in the transverse diameter.

Intercostal muscle action inferred from finite-element analysis

1991 ◽  
Vol 70 (6) ◽  
pp. 2712-2718 ◽  
Author(s):  
S. H. Loring ◽  
J. A. Woodbridge
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Respiratory Muscles ◽  
Intercostal Muscle ◽  
External Layer ◽  
Element Analysis ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Muscle Actions

The external and internal intercostal muscles are important respiratory muscles in humans, but their mechanical actions have been controversial. We used finite-element analysis based on anatomic and mechanical measurements in dogs to assess the action of the intercostal and other rib cage muscles in a model of an isolated canine rib cage. When intercostal muscle forces of either the internal or the external layer were applied in a single interspace, they pulled the adjacent ribs together, consistent with published observations in dogs. However, when the forces were applied in all interspaces, the external layer caused an inspiratory motion and the internal layer caused an expiratory motion, consistent with conventional understanding of intercostal muscle actions. Parasternal intercostal, levator costae, and transversus thoracis (triangularis sterni) muscle actions were also simulated. These muscles caused expected movements of the ribs and sternum. We conclude that the actions of intercostal muscles depend on the spatial extent of their activation. Their actions in a single interspace and in multiple interspaces can be observed and explained with three-dimensional finite-element models.

scholarly journals New electrical parameters extraction method based on simplified 3D model using finite element analysis

2019 ◽  
Vol 39 (2) ◽  
pp. 297-316
Author(s):  
Jorge Rafael González-Teodoro ◽  
Enrique González Romero-Cadaval ◽  
Rafael Asensi ◽  
Roberto Prieto ◽  
Vladimir Kindl
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Fem Analysis ◽  
Parameter Extraction ◽  
Three Dimensions ◽  
Electrical Parameters ◽  
Element Analysis ◽  
Content Type ◽  
Cpu Time

Purpose The purpose of this paper is the presentation of an electrical equivalent circuit for inductive components as well as the methodology for electrical parameter extraction by using a 3 D finite element analysis (FEA) tool. Design/methodology/approach A parameter extraction based on energies has been modified for three dimensions. Some simplifications are needed in a real model to make the 3 D finite element method (FEM) analysis operative for design engineers. Material properties for the components are modified at the pre-modeling step and a corrector factor is used at the post-modeling step to achieve the desired accuracy. Findings The current hardware computational limitations do not allow the 3 D FEA for every magnetic component, and due to the component asymmetries, the 2 D analysis are not precise enough. The application of the new methodology for three dimensions to several actual components has shown its usefulness and accuracy. Details concerning model parameters extration are presented with simulation and measurement results at different operation frequencies from 1 kHz to 1 GHz being the range of switching frequencies used by power electronic converters based on Si, SiC or GaN semiconductors. Practical implications This new model includes the high-frequency effects (skin effect, proximity effect, interleaving and core gap) and other effects can be only analyzed in 3 D analysis for non-symmetric components. The electrical parameters like resistance and inductance (self and mutual ones) are frequency-dependent; thus, the model represents the frequency behavior of windings in detail. These parameters determine the efficiency for the inductive component and operation capabilities for the power converters (as in the voltage boost factor), which define their success on the market. Originality/value The user can develop 3 D finite element method (FEM)-based analyses with geometrical simplifications, reducing the CPU time and extracting electrical parameters. The corrector factor presented in this paper allows obtaining the electrical parameters when 3D FE simulation would have developed without any geometry simplications. The contribution permits that the simulations do not need a high computational resource, and the simulation times are reduced drastically. Also, the reduced CPU time needed per simulation gives a potential tool to optimize the non-symmetric components with 3 D FEM analysis.

scholarly journals Effect of intercostal muscle contraction on rib motion in humans studied by finite element analysis

2018 ◽  
Vol 125 (4) ◽  
pp. 1165-1170 ◽  
Author(s):  
Guangzhi Zhang ◽  
Xian Chen ◽  
Junji Ohgi ◽  
Fei Jiang ◽  
Seiryo Sugiura ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Muscle Contraction ◽  
Muscle Force ◽  
Special Structure ◽  
Tissue Deformation ◽  
Intercostal Muscle ◽  
Element Analysis ◽  
Rib Cage ◽  
Intercostal Muscles

The effect of intercostal muscle contraction on generating rib motion has been investigated for a long time and is still controversial in physiology. This may be because of the complicated structure of the rib cage, making direct prediction of the relationship between intercostal muscle force and rib movement impossible. Finite element analysis is a useful tool that is good at solving complex structural mechanic problems. In this study, we individually activated the intercostal muscle groups from the dorsal to ventral portions and obtained five different rib motions classified based on rib moving directions. We found that the ribs cannot only rigidly rotate around the spinal joint but also be deformed, particularly around the relatively soft costal cartilages, where the moment of muscle force for the rigid rotation is small. Although the intercostal muscles near the costal cartilages cannot generate a large moment to rotate the ribs, the muscles may still have a potential to deform the costal cartilages and contribute to the expansion and contraction of the rib cage based on the force-length relationship. Our results also indicated that this potential is matched well with the special shape of the costal cartilages, which become progressively oblique in the caudal direction. Compared with the traditional explanation of rib motion, by additionally considering the effect from the tissue deformation, we found that the special structure of the ventral portion of the human rib cage could be of mechanical benefit to the intercostal muscles, generating inspiratory and expiratory rib motions. NEW & NOTEWORTHY Compared with the traditional explanation of rib motion, additionally considering the effect from tissue deformation helps us understand the special structure of the ventral portion of the human rib cage, such that the costal cartilages progressively become oblique and the costochondral junction angles gradually change into nearly right angles from the upper to lower ribs, which could be of mechanical benefit to the intercostal muscles in the ventral portion, generating inspiratory and expiratory rib motions.

Strength Finite Element Analysis and Test Research of Steel Package Rotation Table Beam and Tumbler

2012 ◽  
Vol 605-607 ◽  
pp. 258-262
Author(s):  
Jun Qing Liu ◽  
Hong Yu Liu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Relative Displacement ◽  
Three Dimensions ◽  
Relative Distribution ◽  
Ansys Software ◽  
Element Analysis ◽  
Distribution Rules ◽  
Finite Element Numerical Simulation

In order to research the work status of steel package rotation table beam and tumbler, Pro/ENGINEER Wildfire software was adopted on establishing the three dimensions model of steel package rotation table beam and tumbler. ANSYS software was adopted on strength finite element analysis of steel package rotation table beam and tumbler under carrying 370 tons liquid steel package. Relative displacement figure, stress figure and strain figure were obtained. Relative distribution rules of displacement, stress and strain were found. Strain and stress on key positions of steel package rotation table beam were tested and analyzed. The relative error between tested value and finite element numerical simulation results of strain and stress on steel package rotation table beam was computed and analyzed. The method of combining finite element numerical simulation and test research provides important reference basis on the improvement of steel package rotation table.

Cuspal Flexure and Stress in Restored Teeth Caused by Amalgam Expansion

2018 ◽  
Vol 43 (6) ◽  
pp. E300-E307
Author(s):  
BT Danley ◽  
BN Hamilton ◽  
D Tantbirojn ◽  
RE Goldstein ◽  
A Versluis
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Repeated Measures ◽  
Storage Time ◽  
Three Dimensions ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Multivariate Tests ◽  
The Difference ◽  
Amalgam Fillings

SUMMARY Objective: Cracks in amalgam-filled teeth may be related to amalgam expansion. This study measured cuspal flexure and used finite element analysis to assess associated stress levels in amalgam-filled teeth. Methods and Materials: External surfaces of 18 extracted molars were scanned in three dimensions. Nine molars were restored with mesio-occluso-distal amalgam fillings; the other teeth were left intact as controls. All teeth were stored in saline and scanned after two, four, and eight weeks. Cuspal flexure and restoration expansion were determined by calculating the difference between scanned surfaces. Stresses in a flexed tooth were calculated using finite element analysis. Results: Cusps of amalgam-filled teeth flexed outward approximately 3 μm, and restoration surfaces expanded 4 to 8 μm during storage. Cuspal flexure was significantly higher in the amalgam group (multivariate tests, p<0.05), but storage time had no significant effect (repeated measures, p>0.05). Expansion caused stress concentrations at the cavity line angles. These stress concentrations increased stresses due to mastication 44% to 178%. Conclusions: Amalgam expansion pushed cavity walls outward, which created stress concentrations at the cavity line angles. Expansion stresses can raise stresses in amalgam-filled teeth and contribute to incidentally observed cracks.

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