INVESTIGATING BIOMECHANICS OF DIFFERENT MATERIALS AND ANGLES OF BLADES OF FORCEPS FOR OPERATIVE DELIVERY BY FINITE ELEMENT ANALYSIS

2016 ◽  
Vol 16 (04) ◽  
pp. 1650046 ◽  
Author(s):  
KUO-MIN SU ◽  
MU-HSIEN YU ◽  
HER-YOUNG SU ◽  
YU-CHI WANG ◽  
KUO-CHIH SU

Using of forceps during labors and vaginal delivery accomplished operative deliveries in some circumstances. Forceps may induce fractures in the neonatal skull if excessive force is applied to it during an operative delivery. Therefore, newborns may be affected by forceps. The aim of this study was to investigate the effects of different curve angles and materials of the blades of forceps on neonates during labor or delivery for gynecologists and obstetricians using a finite element analysis (FEA). Computer models of the forceps, neonate’s scalp, and skull, were generated for the FEA. Moreover, the use of different materials (stainless steel and titanium alloy) and three different angles of the blades of forceps (20[Formula: see text], 40[Formula: see text], and 60[Formula: see text]) on a newborn’s head were simulated in a biomechanical analysis. The results indicate that a larger curve angle of the blades of forceps can decrease the stress and pressure on the neck of the newborn but may lead to rotation toward the posterior side. Moreover, forceps made of a lower Young’s modulus material can also reduce the stress and pressure on the neck of the newborn. It is hoped that this research can provide a more reasonable reference for manufacturers to design better medical equipment such as forceps in the future for obstetricians and gynecologists to use to attenuate the stress and pressure on the neck of a newborn.

Author(s):  
James K. Wilkins

A project has been conducted to verify a finite element analysis procedure for studying the nonlinear behavior of 90°, stainless steel, 4 inch schedule 10, butt welding elbows. Two displacement controlled monotonic in-plane tests were conducted, one closing and one opening, and the loads, displacements, and strains at several locations were recorded. Stacked 90° tee rosette gages were used in both tests because of their ability to measure strain over a small area. ANSYS shell element 181 was used in the FEA reconciliations. The FEA models incorporated detailed geometric measurements of the specimens, including the welds, and material stress-strain data obtained from the attached straight piping. Initially, a mesh consisting of sixteen elements arrayed in 8 rings was used to analyze the elbow. The load-displacement correlation was quite good using this mesh, but the strain reconciliation was not. Analysis of the FEA results indicated that the axial and hoop strain gradients across the mid-section of the elbow were very high. In order to generate better strain correlations, the elbow mesh was refined in the mid-section of the elbow to include 48 elements per ring and an additional six rings, effectively increasing the element density by nine times. Using the refined mesh produced much better correlations with the strain data.


Author(s):  
Valentin Mereuta

Abstract: In this work the 3D model of the camshaft was done using Autodesk Inventor version 2021 with the literature data and finite element analysis is performed by applying restrictions and loads conditions, first by the absence of the torque and then by applying the torque. Three materials were analyzed in both situations: Cast Iron, Stainless Steel AISI 202 and Steel Alloy. Following the comparative study for the three materials, it can be specified the importance of the material for the construction of the camshaft. Keywords: Camshaft, Static analysis, Autodesk Inventor


2018 ◽  
Vol 23 (5) ◽  
pp. 825-833 ◽  
Author(s):  
Hidetatsu Tanaka ◽  
Go Yamako ◽  
Hiroaki Kurishima ◽  
Shutaro Yamashita ◽  
Yu Mori ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yi Mao ◽  
Xuzhuo Chen ◽  
Shiqi Yu ◽  
Weifeng Xu ◽  
Haiyi Qin ◽  
...  

Abstract This study is the first attempt to explore the reason of costochondral graft fracture after lengthy mandible advancement and bilateral coronoidectomy by combining finite element analysis and mechanical test. Eleven groups of models were established to simulate costochondral graft reconstruction in different degrees of mandible advancement, ranging from 0 to 20 mm, in 2 mm increment. Force and stress distribution in the rib-cartilage area were analyzed by finite element analysis. Mechanical test was used to evaluate the resistance of the rib-cartilage complex. Results showed a sharp increase in horizontal force between 8 and 10 mm mandible advancement, from 26.7 to 196.7 N in the left side, and continue increased after 10 mm, which was beyond bone-cartilage junction resistance according to mechanical test. Therefore, we concluded that bilateral reconstruction with coronoidectomy for lengthy mandible advancement (≥ 10 mm) may lead to prominent increase in shear force and result in a costal-cartilage junction fracture, in this situation, alloplastic prosthesis could be a better choice. We also suggested that coronoidectomy should be carefully considered unless necessary.


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