The Equivalence Method of Protective Structures

2011 ◽  
Vol 197-198 ◽  
pp. 1704-1707
Author(s):  
Zhong Guo Zhang ◽  
Bin Gao ◽  
Zhao Hui Liu
Keyword(s):  
Cross Section ◽  
Cross Sectional Area ◽  
Protective Structure ◽  
Sectional Area ◽  
Cross Sectional ◽  
Usual Model ◽  
Reinforcing Ribs ◽  
The Cross ◽  
Protective Structures ◽  
The Impact

In this paper, according to the structure of warships, the equivalence method of the protective structure with reinforcing ribs is presented abided by the principal of equivalence in rigidity. The minimized model and the equivalence model of the protective structure with reinforcing ribs penetrated by projectiles are investigated in experiment and numerical simulations, and the results show that the equivalence method of the protective structure is reasonable. The reinforcing ribs are extensively used in protective structures, especially in ship structures. The reinforcing ribs are characterized in extensive distribution range and little weight of unit length, and have the main effect that the rigidity requirement of the structure is satisfied so that the structure has enough rigidity stability. However, the big and the small reinforcing ribs in actual structures originally have small size of the cross sectional area (CSA). According to a usual model research method, after an original structure is proportionally reduced according to the minimized proportion of one to four [1], the size of the CSA of the big and the small reinforcing ribs becomes smaller, and the shape of the cross sectional area is shown in Figure1. Under such circumstances, an experimental research on the dynamic response of the reinforcing ribs under the impact load has the characteristics of great difficulty and bad feasibility, and in addition, the reliability of reflecting target characteristic by a proportionally reduced model is very low[2]. In order to study the action of the reinforcing ribs more objectively, the T-shaped cross section of the reinforcing ribs is converted to a rectangular cross section according to the principle of rigidity equivalence, and then, the action can be researched actually. The study method is given as follows.

scholarly journals Analisa Pengaruh Luas Penampang Penghantar dan Cuaca Terhadap Rugi Daya Akibat Korona Pada SUTT 150 kV (Studi Kasus: Gardu Induk Bangkalan – Gardu Induk Sampang)

2019 ◽  
Vol 11 (2) ◽  
pp. 149-159
Author(s):  
Ibnu Hajar ◽  
Tito Dias Fernando
Keyword(s):  
Air Temperature ◽  
Electrical Power ◽  
Cross Sectional Area ◽  
Electricity Sector ◽  
Sectional Area ◽  
Power Losses ◽  
Cross Sectional ◽  
The Cross ◽  
The Impact ◽  
Corona Losses

PT. PLN (PERSERO) as a state-owned company responsible in the electricity sector is required to improve the quality of electricity transmission. In the transmission of electrical power to consumers will be got losses of power. Raising the voltage is an alternative to this problem but it creates new problems because the higher the voltage has increased the corona will occur. The impact of the corona in addition to damaging equipment, noise, and disturbing radio waves, the corona also causes power losses that are proportional to the length of the transmission line. This study uses a quantitative method, by calculating the corona power losses by comparing 4 different cross-sectional areas of the conductor and 4 different air temperatures. The results of this study found that the smaller the cross-sectional area of the conductor the power losses due to corona are smaller, conversely the greater the cross-sectional area the greater the power losses. At the smallest cross-sectional area of 282.6 mm2, the power losses that occurred were 2.013% and at the largest cross-sectional area of 378.7 mm2, the power losses were 5.251%. While the influence of air temperature, the lowest corona losses occur at 29 0C which are 1,223,886 kW and the biggest occur at 24 0C which are 1,373,419 kW, so the higher the air temperature the smaller the corona losses, conversely the lower the air temperature than the higher the corona losses that occur.

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.

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.

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.

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.

A New Method of Measuring the Cross-Sectional Area of Connective Tissue Structures

1988 ◽  
Vol 110 (2) ◽  
pp. 104-109 ◽  
Author(s):  
N. G. Shrive ◽  
T. C. Lam ◽  
E. Damson ◽  
C. B. Frank
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Connective Tissues ◽  
Maximum Width ◽  
Cross Sectional ◽  
Elliptical Cross ◽  
The Cross

There appears to be no generally accepted method of measuring in-situ the cross-sectional area of connective tissues, particularly small ones, before mechanical testing. An instrument has therefore been devised to measure the cross-sectional area of one such tissue, the rabbit medial collateral ligament, directly and nondestructively. However, the methodology is general and could be applied to other tissues with appropriate changes in detail. The concept employed in the instrument is to measure the thickness of the tissue as a function of position along the width of the tissue. The plot obtained of thickness versus width position is integrated to provide the cross-sectional area. This area is accurate to within 5 percent, depending mainly on alignment of the instrument and pre-load of the ligament. Results on the mid-substance of the rabbit medial collateral ligaments are repeatable and reproducible. Values of maximum width and thickness are less variable than those obtained with a vernier caliper. The measured area is considerably less than that estimated assuming rectangular cross-section and slightly less than that estimated on the assumption of elliptical cross-section.

Geometric Design of Rectangular Cross-Sectional Springs

2018 ◽  
Vol 920 ◽  
pp. 126-131
Author(s):  
Yeong Maw Hwang ◽  
D.S. Lin ◽  
Sheng Liang Lin
Keyword(s):  
Shear Stress ◽  
Cross Section ◽  
Maximum Shear Stress ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Rectangular Section ◽  
Cross Sectional ◽  
Short Side ◽  
The Cross ◽  
Sectional Shape

In order to study the influence of the cross-sectional shape on the stiffness of a spring, a finite element analysis software DEFORM is used to simulate and analyze the torsion of rectangular cross-section bars. The material of the bar is TS1800 SAE9254 and the cross-section of aspect ratio (w / h) is 1.5. From literature it is known that when the rectangular section bar is twisted, the shear stress at the four corners is zero, so elliptical corners can decrease the volume and increase the stiffness with the same volume. Five levels for the long side of the elliptical corner are set as 1 to 5 mm, and 3 levels are set for the short side. Torsion of the rectangular section bars under 15 kinds of geometric designs are simulated to find the preferred cross-sectional shape design by evaluating the cross-sectional area, load, and the maximum shear stress. The objective of the design is obtaining a uniform stress distribution with a larger spring stiffness and lighter weight. The optimal cross section of the bars is established as the spring geometry, and the pre-loading processing of the spring is simulated. The required load and the maximum shear stress data are obtained. The effects of load, cross-sectional area and maximum shear stress on the springs performance are investigated.

What does inductance plethysmography really measure?

1988 ◽  
Vol 64 (4) ◽  
pp. 1749-1756 ◽  
Author(s):  
P. Martinot-Lagarde ◽  
R. Sartene ◽  
M. Mathieu ◽  
G. Durand
Keyword(s):  
Computed Tomography ◽  
Cross Section ◽  
Relative Error ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Pattern Shape ◽  
The Cross

Inasmuch as it has been claimed that inductance plethysmography can measure cross-sectional area changes, we tested this assumption. We present experimental and computed relationships between self-inductance (L) of coils and areas (A) included inside for a coil with a well-defined side wavy pattern (triangular or sinusoidal) and for a real belt (Respitrace) placed on elliptical or rectangular configurations. The results are applied to the physiological field using measurements obtained from a computed tomography experiment. We demonstrate that the L-A relationships vary not only with shape or ellipticity of the cross section but also with the wavy pattern shape. This last parameter is critical because it is difficult to actually control. When the coil wavy pattern remains steady, there are some physiological situations where inductance plethysmography can more accurately estimate area changes: when the configuration shape is constant, the correspondence between delta L and delta A is almost linear with a shape-dependent sensitivity; when the configuration is nearly circular (ellipticity in the range 0.8-1), the relative error in delta A estimation is less than 5%.

scholarly journals ДО ВИЗНАЧЕННЯ УРІВНОВАЖУВАЛЬНОЇ НАВАНТАГИ НА ШПАНГОУТ ОДНОПАЛУБНОГО ФЮЗЕЛЯЖУ

2021 ◽  
pp. 113-121
Author(s):  
А. Г. Дибир ◽  
А. А. Кирпикин ◽  
Н. И. Пекельный
Keyword(s):  
Cross Section ◽  
Cross Sectional Area ◽  
Torsional Stiffness ◽  
Vertical Position ◽  
Sectional Area ◽  
Cross Sectional ◽  
Optimal Position ◽  
Load Bearing ◽  
The Cross ◽  
Fuselage Skin

With the optimal design of the fuselage, a very important issue is the choice of the optimal position of the load-bearing floor in the cross-section of the fuselage.Depending on the relative position of the load-bearing floor, the reduced thickness of the floor, the scheme of fastening the floor to the frames and the ratio of the reduced thicknesses of the fuselage skin and the floor, the position of the center of stiffness of the fuselage cross-section changes, the torsional stiffness of the fuselage. This leads to a change in torque, a redistribution of shear flows, a redistribution of flattening loads on the frame from the bending of the fuselage.In this work, two schemes of fastening the floor to the frame are considered - a rigid, torque connection and a hinged one. In this case, the frame takes up additional load from the floor. The fuselage is considered as a thin-walled rod, loaded with horizontal and vertical shear forces, torque and flattening forces from the fuselage bending.For reliability, the calculation of the position of the center of stiffness in a double-closed cross-section was carried out by two methods: a fictitious force and a fictitious moment. The influence of various parameters on the location of the center of rigidity was investigated. The influence of the vertical position of the floor, the ratio of the reduced thicknesses of the floor and the fuselage skin and the cross-sectional area of the beams of the floor attachment to the fuselage on the position of the center of stiffness was evaluated. Diagrams of these dependencies were constructed based on the results of calculations. The dependence of the torsional stiffness on the position of the floor and the ratio of the reduced thicknesses of the floor and the fuselage skin was investigated. Based on the calculation results, a diagram of these dependencies was built. Various constructive solutions were considered for fastening the floor to the fuselage skin: with their direct connection and with the floor support only on the beam. The floor loading from flattening loads caused by the bending of the fuselage was studied. The diagram of the loading of the frame and the floor from flattening loads is shown.According to the diagrams, you can choose the optimal vertical position of the floor, the reduced floor thickness and the cross-sectional area of the beam

The Labyrinthine Portion of the Facial Canal

1987 ◽  
Vol 28 (1) ◽  
pp. 17-23 ◽  
Author(s):  
K. Wadin ◽  
H. Wilbrand
Keyword(s):  
Computed Tomography ◽  
Temporal Bone ◽  
Cross Section ◽  
Cross Sectional Area ◽  
Medial Part ◽  
Facial Canal ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross ◽  
Shape And Size

The variational radiographic anatomy of the labyrinthine portion of the facial canal was investigated in 200 plastic and silicone casts of unselected temporal bone specimens by means of multidirectional and computed tomography in different projections. The labyrinthine portion of the canal varied considerably in shape and size; in some specimens the cross-section was circular, but often the canal was crumpled and flattened in its passage above the cochlea. The medial part of the labyrinthine portion was narrowest, the lowest cross-sectional area being 0.5 mm2. In spite of optimal positioning of the specimen it was not always possible to reproduce the entire labyrinthine portion of the canal completely. Most difficult to reproduce were specimens with extremely small vertical diameters and marked caudal sloping of the canal.

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