Optimization of High Concrete Retaining Wall Structure

2013 ◽  
Vol 357-360 ◽  
pp. 597-603
Author(s):  
Su Yang Gao ◽  
Yan Chen ◽  
Yao Feng Xie ◽  
Wen Dong Lei ◽  
Kai Yin
Keyword(s):  
Cross Section ◽  
Optimization Design ◽  
Retaining Wall ◽  
Cross Sectional Area ◽  
Wall Structure ◽  
Sectional Area ◽  
Cross Sectional ◽  
Structure Selection ◽  
Great Height ◽  
The Stability

The height of vertical pier retaining wall is relatively larger in regions with great height of water. As the retaining wall becomes higher, the cross-sectional area of ordinary gravity pier structure becomes larger and foundation strength needs to be larger, thus there are some restrictions for traditional structure form. This research focuses on new structure forms of high concrete retaining wall and its optimization design for piers in regions with great height of water. This study establishes a nonlinear constrained mathematical model of pier high retaining wall structures. The objective function is cross-sectional area of the pier retaining wall which is restricted by the stability, bearing capacity of foundation and strength of cross-section of retaining wall. This model is solved by fmincon function from Matlab and the results present an economically reasonable cross-section form. This new selection is greatly significant to improve the stability of high concrete retaining wall and reduce the project cost. The new structure is successfully used in a port of Huaihe River and it can be a solution to pier structure selection problem in regions with great height of water in the future.

scholarly journals Numerical simulation of cutting layer in internal corners milling

Mechanik ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 412-414
Author(s):  
Jan Burek ◽  
Rafał Flejszar ◽  
Barbara Jamuła
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Cross Section ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
The Cross ◽  
The Stability

The analytical and numerical model of the cross-section of the machined layer in the process of milling of concave rounding is presented. Simulation tests were carried out to determine the cross-sectional area of the cutting layer. A strategy has been developed that allows to increase the stability of the cross-section area of the cutting layer when the mill enters the inner corner area.

Modelling the Acoustical and Airflow Performance of Simple Lined Ventilation Apertures

2005 ◽  
Vol 12 (4) ◽  
pp. 277-292 ◽  
Author(s):  
D J Oldham ◽  
Jian Kang ◽  
M W Brocklesby
Keyword(s):  
Aspect Ratio ◽  
Cross Section ◽  
High Aspect Ratio ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Ventilation Performance ◽  
Acoustic Treatment

The pressure differences that can be used to drive a natural ventilation system are very small and thus large apertures are required to allow sufficient air to enter and leave a building to ensure good air quality or thermal comfort. Large apertures are potential acoustic weak points on a façade and may require some form of acoustic treatment such as absorbent linings, in which case the ventilator is similar to a short section of lined duct. In ducts, the performance of absorbent linings increases with the length of lining and the ratio of the length of lined perimeter to the cross sectional area of the duct. Thus, for a duct of a given cross sectional area, a lining is more effective for a duct with a high aspect ratio than for a duct with a square cross section. However, the high aspect ratio cross section will result in greater flow resistance and impede the airflow performance. In this paper numerical methods are employed to investigate the effect of different configurations of a lined aperture on the acoustical and ventilation performance of the aperture in order to establish the optimum configurations.

Normalization of force generated by canine airway smooth muscles

1991 ◽  
Vol 260 (6) ◽  
pp. L522-L529 ◽  
Author(s):  
H. Jiang ◽  
A. J. Halayko ◽  
K. Rao ◽  
P. Cunningham ◽  
N. L. Stephens
Keyword(s):  
Smooth Muscle ◽  
Cross Section ◽  
Cross Sections ◽  
Smooth Muscles ◽  
Muscle Cells ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Muscle Stress ◽  
Total Tissue

A variety of normalizations have been employed to compare maximal isometric force (Po) produced by smooth muscles at different locations and stages of maturation. Because these procedures have not always been based on rigorous principles, confusion has resulted. To obtain a less ambiguous index of force production, we measured in vitro Po from mongrel canine tracheal (TSM) and bronchial (BSM) smooth muscle with an electromagnetic lever and normalized it to force per unit cross-sectional area of whole tissue (tissue stress), to force per unit cross-sectional area of muscle in the cross section of total tissue (muscle stress), and to force per fractional unit of myosin in the tissue cross section (myosin stress). Proportion of myosin in cross-sectional area of tissue was deduced from data obtained by sodium dodecyl sulfate gel electrophoresis of crude muscle extracts. For TSM, tissue stress was 1.499 X 10(5) N/m2 +/- 0.1 (SE), whereas it was only 0.351 X 10(5) N/m2 +/- 0.05 (SE) for BSM, representing a 4.27-fold difference (P less than 0.01). There was a 1.60-fold difference (P less than 0.05) in muscle stress, which was correlated to the morphometric finding that 79 +/- 1.4% (SE) of the tracheal strip cross section was muscle, whereas only 30 +/- 1.0% (SE) of bronchial tissue was occupied by muscle. Average myosin content was the same in smooth muscle cells of TSM and BSM, indicating that total amount of myosin in tissue cross sections was essentially a function of proportional area of muscle cells in total tissue cross sections.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimization Design of an Efficient Evacuator for Gun Barrels

2021 ◽  
Author(s):  
Quanzhao Sun ◽  
Li Chen ◽  
Jie Zhang ◽  
Yanming Song ◽  
Guolai Yang ◽  
...  
Keyword(s):  
Optimization Design ◽  
Structural Parameters ◽  
Cross Sectional Area ◽  
Main Function ◽  
Sectional Area ◽  
Working Process ◽  
Cross Sectional ◽  
Mathematical Expressions ◽  
Reliability Indicator ◽  
The Cross

Abstract Evacuators are key components of gun barrels, and their main function is to drain the gunpowder gas remaining in the gun bore from the muzzle by ejection. To design an efficient evacuator for the gun barrels, an optimization model with the mathematical expressions describing the working process of the evacuator was established. The four structural parameters that affect the efficiency of the evacuator, including the volume of the gas storage cylinder chamber, the distance of the nozzle from the muzzle end face, the cross-sectional area of the nozzles and the cross-sectional area of the valves, were optimized. The effective working time and reliability indicator of the optimized evacuator were improved. This work describes a framework for improving the design of highly efficient evacuators on gun barrels.

Corrosion-Induced Concrete Cracking, Steel-Concrete Bond Loss, and Mechanical Degradation of Steel Bars

2014 ◽  
Vol 919-921 ◽  
pp. 1760-1770 ◽  
Author(s):  
Fu Jian Tang ◽  
Gen Da Chen ◽  
Wei Jian Yi
Keyword(s):  
Cross Section ◽  
Crack Width ◽  
Surface Profile ◽  
Concrete Surface ◽  
Cross Sectional Area ◽  
Mechanical Degradation ◽  
Sectional Area ◽  
Cross Sectional ◽  
Steel Bars ◽  
The Cross

This study experimentally investigated corrosion-induced deterioration in reinforced concrete (RC) structures: concrete cover cracking, steel-concrete bond loss, and mechanical degradation of corroded steel bars. Pullout and RC beam specimens were prepared, subjected to accelerated corrosion in a wet sand bath, and tested under loading. A 3D laser scan was employed to measure the surface profile of corroded steel bars and determine the corrosion effect on the distribution of residual cross section area. The crack width on the concrete surface was sampled randomly and analyzed statistically. Corrosion reduced the bond strength between steel bars and concrete, particularly in the form of corrosion-induced number and width of cracks. Both the yield and ultimate strengths depended upon the critical cross sectional area of steel bars, whereas the elongation changed with the cross section distribution over the length of the steel bars. Corrosion also changed the distribution of the cross sectional area of steel bars. The crack width on the concrete surface can be well represented by a normal distribution regardless of corrosion levels.

Dynamic Detection and Analysis of Raw Silk’s Flatness

2011 ◽  
Vol 175-176 ◽  
pp. 385-388
Author(s):  
Xin Zhang ◽  
Yi Quan Xu ◽  
Kai Meng ◽  
Qing Guan Chen
Keyword(s):  
Cross Section ◽  
Axial Length ◽  
Minor Axis ◽  
Cross Sectional Area ◽  
Elliptical Cross Section ◽  
Sectional Area ◽  
Cross Sectional ◽  
Elliptical Cross ◽  
Photoelectric Sensor ◽  
Dynamic Detection

The shape of most raw silk’s cross-section can be regarded as ellipse approximately. Axial length of the raw silk’s cross-section was detected and recorded dynamically by photoelectric sensor combined with the software of LabVIEW. Two photoelectric sensors were located orthogonally to measure axial lengths of the ellipse. The major and minor values can be considered as the major and minor axis values of the raw silk’s elliptical cross-section respectively. Thereby, the flatness and the area of raw silk’s cross-section can be calculated according to the values of major and minor axes. In addition, the raw silk’s evenness was characterized based on the variation of the cross-sectional area.

Analysis of the Cross-Sectional Area of the Adductor Longus Tendon

2007 ◽  
Vol 35 (6) ◽  
pp. 996-999 ◽  
Author(s):  
Eric J. Strauss ◽  
Kirk Campbell ◽  
Joseph A. Bosco
Keyword(s):  
Cross Section ◽  
Muscle Fibers ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Sectional Anatomy ◽  
Longus Muscle ◽  
The Cross ◽  
Adductor Longus ◽  
Muscle Origin

Background Strain injury to the adductor longus muscle is a common cause of groin pain in athletes and generally occurs in the proximal portion of the muscle, near its origin from the anterior aspect of the pubis. The composition and cross-sectional anatomy of this muscle's origin has not been previously described. Hypothesis We hypothesize that the adductor longus muscle origin is composed mainly of muscle fibers and that the tendon composes only a small part of the cross section at the origin of the muscle. Study Design Descriptive laboratory study. Methods We harvested 42 adductor longus muscles from 28 cadavers and measured the cross-sectional dimensions of the tendon with microcalipers. Next, we determined the relative contributions of the tendon and muscle fibers to the cross-sectional anatomy of the muscle using optical scanning. These 2 sets of measurements were obtained at 3 locations: at the muscle origin and 1.0 and 2.0 cm distal to the origin. Results The average length and width of the tendon was 11.6 and 3.7 mm, respectively, at the origin. The average cross-sectional areas of the tendon were 49.3, 27.9, and 25.7 mm2 at points 0.0, 1.0, and 2.0 cm from its origin, respectively. The origin of the adductor longus muscle was composed of 37.9% tendon and 62.1% muscle tissue. At 1.0 cm from the origin, the percentage of tendon decreased to 34%. At 2.0 cm from the origin, the tendon composed 26.7% of the cross section. Conclusion The cross-sectional area of the tendon of the adductor longus muscle is relatively small. The muscle origin is composed predominantly of direct attachment of muscle fibers. Clinical Relevance Knowledge of the cross-sectional anatomy of the adductor longus muscle at its origin may help clinicians better understand the complex nature of injuries in this area.

Myogenic response of rat femoral small arteries in relation to wall structure and [Ca2+]i

2002 ◽  
Vol 283 (1) ◽  
pp. H118-H125 ◽  
Author(s):  
Vladimir V. Matchkov ◽  
Olga S. Tarasova ◽  
Michael J. Mulvany ◽  
Holger Nilsson
Keyword(s):  
Intracellular Calcium ◽  
External Iliac Artery ◽  
Wall Stress ◽  
Calcium Sensitivity ◽  
Contralateral Side ◽  
Cross Sectional Area ◽  
Wall Structure ◽  
Sectional Area ◽  
Cross Sectional ◽  
Small Arteries

The present study investigated the influence of media thickness on myogenic tone and intracellular calcium concentration ([Ca2+]i) in rat skeletal muscle small arteries. A ligature was loosely tied around one external iliac artery of 5-wk-old spontaneously hypertensive rats. At 18 wk of age, femoral artery blood pressure was 102 ± 11 mmHg ( n = 15) on the ligated side and 164 ± 6 mmHg ( n = 15) on the contralateral side. Small arteries feeding the gracilis muscle had a reduced media cross-sectional area and a reduced media-to-lumen ratio on the ligated side, where also the range of myogenic constriction was shifted to lower pressures. However, when expressed as a function of wall stress, diameter responses were nearly identical. [Ca2+]i was higher in vessels from the ligated hindlimb at pressures above 10 mmHg, but vasoconstriction was not accompanied by changes in [Ca2+]i. Thus the myogenic constriction here seems due primarily to changes in intracellular calcium sensitivity, which are determined mainly by the force per cross-sectional area of the wall and therefore altered by changes in vascular structure.

Scanning esophageal impedance probe for measurement of luminal cross section.

1979 ◽  
Vol 236 (5) ◽  
pp. E545
Author(s):  
D A Mary ◽  
P J North ◽  
J N Hunt
Keyword(s):  
Cross Section ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Dynamic Changes ◽  
Cross Sectional ◽  
Variable Voltage ◽  
Electrode Assemblies ◽  
Impedance Probe ◽  
The Cross ◽  
Esophageal Impedance

A scanning esophageal probe for measuring luminal cross section is described. Current is injected into electrode assemblies so that a variable voltage output directly proportional to interelectrode impedance and inversely proportional to cross-sectional area of the medium around the electrodes may be measured. The device is capable of measuring the cross section of glass cylinders. It was used in one esophagus to measure the cross-sectional area of different sizes of swallowed bolus. The probe offers a safe and repeatable method of studying dynamic changes in luminal dimensions of the esophagus.

On the stability of flow in an elliptic pipe which is nearly circular

1994 ◽  
Vol 281 ◽  
pp. 357-369 ◽  
Author(s):  
A. Davey ◽  
H. Salwen
Keyword(s):  
Cross Section ◽  
Specific Problem ◽  
Sectional Area ◽  
Leading Order ◽  
Straight Pipe ◽  
Cross Sectional ◽  
Double Eigenvalue ◽  
Circular Problem ◽  
Qualitative Structure ◽  
The Stability

In an earlier paper (Davey 1978) the first author investigated the linear stability of flow in a straight pipe whose cross-section was an ellipse, of small ellipticity e, by regarding the flow as a perturbation of Poiseuille flow in a circular pipe. That paper contained some serious errors which we correct herein. We show analytically that for the most important mode n = 1, for which the circular problem has a double eigenvalue c0 as the ‘swirl’ can be in either direction, the ellipticity splits the double eigenvalue into two separate eigenvalues c0 ± e2c12, to leading order, when the cross-sectional area of the pipe is kept fixed. The imaginary part of c12 is non-zero and so the ellipticity always makes the flow less stable. This specific problem is generic to a much wider class of fluid dynamical problems which are made less stable when the symmetry group of the dynamical system is reduced from S1 to Z2.In the Appendix, P. G. Drazin describes simply the qualitative structure of this problem, and other problems with the same symmetries, without technical detail.

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