Formability Enhancement in Titanium Tube-Flaring by Manipulating the Deformation Path

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Chetan P. Nikhare ◽  
Yannis P. Korkolis ◽  
Brad L. Kinsey
Keyword(s):  
Major Axis ◽  
Sectional Area ◽  
Deformation Path ◽  
Cross Sectional ◽  
Simple Process ◽  
Step Process ◽  
Tube Flaring ◽  
Titanium Tube ◽  
One Step ◽  
Punch Geometry

The tube flaring process has been traditionally used to expand one end of a tube without changing its cross-sectional area. This simple process typically forms the product using a single punch. To delay failure and enhance formability, a two-step flaring process can be used. For example, if a significant elliptical flared shape is attempted in a one-step process, a necking/tearing failure would occur on the major axis of the ellipse. However, if a two-step process, starting with a mildly elliptical punch and followed by the final, sharply elliptical punch is used instead, the desired elliptical shape can be achieved. In this paper, the effects of the punch geometry of the first step on the deformation paths are numerically analyzed. By manipulating the deformation path, failure can be delayed so that higher formability is achieved. The numerical model is validated by comparison with experimental results.

Formability Enhancement in Titanium Tube Flaring by Controlling the Deformation Path

2014 ◽  
Author(s):  
Chetan P. Nikhare ◽  
Brad L. Kinsey ◽  
Yannis P. Korkolis
Keyword(s):  
Numerical Simulations ◽  
Sectional Area ◽  
Deformation Path ◽  
Cross Sectional ◽  
Simple Process ◽  
Step Process ◽  
Tube Flaring ◽  
Titanium Tube ◽  
One Step ◽  
Punch Geometry

The tube flaring process has been traditionally used to expand one end of the tube without changing its main cross-sectional area. This simple process typically forms the product with a single punch along a unique deformation path. To delay failure and enhance formability, a two-step flaring process can be used. For example, if a significant elliptical flared shape is attempted in a one step process, a tearing failure would occur on the major elliptical axis. However if a two-step process with a mildly elliptical punch, followed by the final elliptical punch was used, the desired elliptical shape can be achieved. In this paper the effects of the punch geometry and forming depth of the first step on the deformation paths were numerically analyzed. By changing the deformation path, failure can be delayed so that higher formability is achieved. The numerical simulations were validated by comparison with experimental results.

scholarly journals Ontogenetic scaling patterns and functional anatomy of the pelvic limb musculature in emus (Dromaius novaehollandiae)

2014 ◽  
Author(s):  
Luis P Lamas ◽  
Russell P Main ◽  
John R. Hutchinson
Keyword(s):  
Body Mass ◽  
Functional Anatomy ◽  
Major Axis ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Positive Allometry ◽  
Dromaius Novaehollandiae ◽  
Pelvic Limb

Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow emus to cope with their rapid growth and locomotion, which can be partly addressed via scaling (allometric) analysis of morphology. In this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area (PCSA) and average tendon cross sectional area from emus across three ontogenetic stages (n=17, body masses from 3.6 to 42 kg). The data were analysed by reduced major axis regression to determine how these biomechanically relevant aspects of morphology scaled with body mass. Muscle mass and PCSA showed a marked trend towards positive allometry (26 and 27 out of 34 muscles respectively) and fascicle length showed a more mixed scaling pattern. The long tendons of the main digital flexors scaled with positive allometry for all characteristics whilst other tendons demonstrated a less clear scaling pattern. Finally, the two longer bones of the limb (tibiotarsus and tarsometatarsus) also exhibited positive allometry for length and the two others (femur and first phalanx of digit III) had trends towards isometry. These results indicate that emus experience a relative increase in their muscle force-generating capacities, as well as potentially increasing the force-sustaining capacities of their tendons, as they grow. Furthermore, we have clarified anatomical descriptions and provided illustrations of the pelvic limb muscle-tendon units in emus.

scholarly journals Ontogenetic scaling patterns and functional anatomy of the pelvic limb musculature in emus (Dromaius novaehollandiae)

2014 ◽  
Author(s):  
Luis P Lamas ◽  
Russell P Main ◽  
John R. Hutchinson
Keyword(s):  
Body Mass ◽  
Functional Anatomy ◽  
Major Axis ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Positive Allometry ◽  
Dromaius Novaehollandiae ◽  
Pelvic Limb

Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow emus to cope with their rapid growth and locomotion, which can be partly addressed via scaling (allometric) analysis of morphology. In this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area (PCSA) and average tendon cross sectional area from emus across three ontogenetic stages (n=17, body masses from 3.6 to 42 kg). The data were analysed by reduced major axis regression to determine how these biomechanically relevant aspects of morphology scaled with body mass. Muscle mass and PCSA showed a marked trend towards positive allometry (26 and 27 out of 34 muscles respectively) and fascicle length showed a more mixed scaling pattern. The long tendons of the main digital flexors scaled with positive allometry for all characteristics whilst other tendons demonstrated a less clear scaling pattern. Finally, the two longer bones of the limb (tibiotarsus and tarsometatarsus) also exhibited positive allometry for length and the two others (femur and first phalanx of digit III) had trends towards isometry. These results indicate that emus experience a relative increase in their muscle force-generating capacities, as well as potentially increasing the force-sustaining capacities of their tendons, as they grow. Furthermore, we have clarified anatomical descriptions and provided illustrations of the pelvic limb muscle-tendon units in emus.

scholarly journals Optimization of Geometric Parameters of Thermal Insulation of Pre-Insulated Double Pipes

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1012 ◽  
Author(s):  
Dorota Krawczyk ◽  
Tomasz Teleszewski
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Cross Section ◽  
Thermal Insulation ◽  
Major Axis ◽  
Heat Losses ◽  
Sectional Area ◽  
Cross Sectional ◽  
Elliptical Shape ◽  
Half Axis

This paper presents the analysis of the heat conduction of pre-insulated double ducts and the optimization of the shape of thermal insulation by applying an elliptical shape. The shape of the cross-section of the thermal insulation is significantly affected by the thermal efficiency of double pre-insulated networks. The thickness of the insulation from the external side of the supply and return pipes affects the heat losses of the double pre-insulated pipes, while the distance between the supply and return pipes influences the heat flux exchanged between these ducts. An assumed elliptical shape with a ratio of the major axis to the minor half axis of an ellipse equaling 1.93 was compared to thermal circular insulation with the same cross-sectional area. All calculations were made using the boundary element method (BEM) using a proprietary computer program written in Fortran as part of the VIPSKILLS project.

scholarly journals Ontogenetic scaling patterns and functional anatomy of the pelvic limb musculature in emus (Dromaius novaehollandiae)

2014 ◽  
Author(s):  
Luis P Lamas ◽  
Russell P Main ◽  
John R. Hutchinson
Keyword(s):  
Body Mass ◽  
Functional Anatomy ◽  
Major Axis ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Fascicle Length ◽  
Cross Sectional ◽  
Positive Allometry ◽  
Dromaius Novaehollandiae ◽  
Pelvic Limb

Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow them to cope through these changes. To answer such questions, in this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area (PCSA) and average tendon cross sectional area from emus across an ontogenetic series (n=17, body masses from 3.6 to 42 kg). The data were analysed by reduced major axis regression to determine scaling relationships with body mass. Muscle mass and PCSA showed a marked trend towards positive allometry (26 and 27 out of 34 muscles respectively) and fascicle length showed a more mixed scaling pattern. The long tendons of the main digital flexors scaled with positive allometry for all characteristics whilst other tendons demonstrated a less clear scaling pattern. Finally, the two longer bones of the limb (tibiotarsus and tarsometatarsus) also exhibited positive allometry for length and the other two (femur and first phalanx of the pes) had trends towards isometry. These results indicate that emus increase their muscle force-generating capacities, as well as potentially increasing the force-sustaining capacities of their tendons, as they grow. Furthermore, we have clarified anatomical descriptions and provided illustrations of the pelvic limb muscle-tendon units in emus.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Changes in the parameters of nasal breathing and parameters of the upper respiratory tract during orthognathic operations in patients with II and III skeletal class of jaw anomalies

2020 ◽  
pp. 22-27
Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev
Keyword(s):  
Respiratory Tract ◽  
Nasal Cavity ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
Upper Respiratory Tract ◽  
Sectional Area ◽  
Nasal Breathing ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Upper Respiratory

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by

Sign in / Sign up

Export Citation Format

Share Document