Minimum-Weight Design of a Statically Determinate Truss Subject to Constraints on Compliance, Stress, and Cross-Sectional Area

1973 ◽  
Vol 40 (1) ◽  
pp. 313-314 ◽  
Author(s):  
W. Prager
Keyword(s):  
Minimum Weight ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Minimum Weight Design ◽  
Cross Sectional ◽  
Weight Design

Analytic Treatment of Minimum Weight Design of Cantilevers

1974 ◽  
Vol 41 (2) ◽  
pp. 512-515
Author(s):  
J. E. Brock
Keyword(s):  
Analytic Solution ◽  
Minimum Weight ◽  
Practical Importance ◽  
Cantilever Beams ◽  
Minimum Weight Design ◽  
Concentrated Force ◽  
Cross Sectional ◽  
Section Modulus ◽  
End Conditions ◽  
Weight Design

Minimum weight design is considered for cantilever beams which must sustain a concentrated moment and a concentrated force at the tip as well as their own distributed weight. An analytic solution is obtained for the case where the variation of cross section is such that section modulus varies as a power of cross-sectional area. Three cases, having practical importance, are studied in detail; two of these lead to nonlinear differential or integral relationships. Cases having more complicated laws of variation and other end conditions are discussed.

Minimum-Weight Design of Thin-Walled Cylinders Subject to Flexural and Torsional Stiffness Constraints

1980 ◽  
Vol 47 (1) ◽  
pp. 106-110 ◽  
Author(s):  
R. D. Parbery ◽  
B. L. Karihaloo
Keyword(s):  
Minimum Weight ◽  
Torsional Stiffness ◽  
Contour Length ◽  
Minimum Weight Design ◽  
Cross Sectional ◽  
Weight Design ◽  
Thin Walled ◽  
Sectional Shape ◽  
Elliptical Cylinders ◽  
Walled Cylinder

We consider the problem of determining the cross-sectional shape of a thin-walled cylinder of constant (unknown) wall thickness and given contour length that uses the least possible material to achieve prescribed minimum stiffness in torsion and bending. The corresponding variational problem is shown to belong to a class with nonadditive functionals whose Euler equation is an integrodifferential equation. Cross-sectional shapes are presented for various stiffness ratios and compared with circular and elliptical cylinders.

Minimum Weight Optimization of Offshore Jackets

1991 ◽  
Vol 113 (4) ◽  
pp. 292-296
Author(s):  
V. S. R. Murty ◽  
C. L. Rao ◽  
K. Rajagopalan
Keyword(s):  
Minimum Weight ◽  
Wave Forces ◽  
Weight Optimization ◽  
Wave Direction ◽  
Minimum Weight Design ◽  
Cross Sectional ◽  
Space Truss ◽  
The World ◽  
Weight Design ◽  
Period Wave

Offshore steel jackets are extensively used all over the world for the extraction of hydrocarbons from the reservoirs lying underneath the seabed. In this paper, the results of research carried out by the authors on the minimum weight optimization of the jacket for wave forces have been described. The gradient projection method has been used in the optimization. The jacket is modeled as a space truss and the cross-sectional areas of the tubular members have been the variables in the optimization process. The optimization histories with different sets of group area variables have been presented. The minimum weight design has been repeated over a range of ocean wave parameters, such as wave period, wave height, and wave direction, and the results are presented to indicate their interplay in the optimal picture.

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

Unequal Probability Scheme for Fruit Count in a Guava Tree

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
R. C. BHARATI
Keyword(s):  
Cross Sectional Area ◽  
Equal Probability ◽  
Sampling Scheme ◽  
Research Station ◽  
Sectional Area ◽  
Cross Sectional ◽  
Unequal Probability ◽  
Selection Probabilities ◽  
Horticultural Research ◽  
Number Of Branches

Data on fruit count corresponding to primary, secondary and tertiary branches of a randomly selected guava CV. Allahabad Safeda were recorded from the guava orchard of Horticultural Research Station, Birauli. The proposed sampling scheme in which the selection probabilities are based on length of braches between two forking points was compared with equal probability(PE), probability proportional to the number of branches(PPN), probability proportional to the cross sectional area (PPA) and probability proportional to volume (PPV) method of sampling and found to be more efficient.

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