The Behavior of Rectangular Plates Under Concentrated Load

1937 ◽  
Vol 4 (2) ◽  
pp. A75-A85
Author(s):  
R. G. Sturm ◽  
R. L. Moore
Keyword(s):  
Flat Plate ◽  
Experimental Work ◽  
General Analysis ◽  
Rectangular Plates ◽  
Flat Plates ◽  
Concentrated Load ◽  
Analytical Work ◽  
Analytical Research

Abstract This paper presents a summary of the experimental and analytical research on flat plates under concentrated normal loads conducted at the Aluminum Research Laboratories. The experimental work includes tests on a number of different sizes of plates, ranging from 1/8 in. to 1 in. thickness, loaded on spans of from 48 to 384 times the thickness. The effect of the degree of load concentration, types of edge support, and position of the load upon the stresses and deflections have been the principal variables studied. Cases of bending alone, and combined bending and direct stress have been considered. The analytical work refers to the existing general analysis of the flat-plate problem, from which formulas suitable for design purposes have been derived.

A Study of the Stresses Around Elliptical Holes in Flat Plates

1971 ◽  
Vol 93 (2) ◽  
pp. 688-694 ◽  
Author(s):  
Norman Jones ◽  
Demosthenes Hozos
Keyword(s):  
Stress Distribution ◽  
Flat Plate ◽  
Experimental Work ◽  
Elastic Stress ◽  
Elliptical Hole ◽  
Finite Width ◽  
Flat Plates ◽  
Elliptical Holes

The theoretical elastic stress distribution is presented for a thin flat plate of finite width which contains an elliptical hole. Various uniaxial and biaxial in-plane loads are applied to the plate and the results are compared with some existing experimental work. The results of a series of photoelastic tests which were arranged to examine the interaction between the stresses around two neighboring elliptical holes in flat plates are also presented.

Line Contact Deformation: A Cylinder Between Two Flat Plates

1981 ◽  
Vol 103 (1) ◽  
pp. 21-25 ◽  
Author(s):  
M. R. Hoeprich ◽  
H. Zantopulos
Keyword(s):  
Plane Strain ◽  
General Equation ◽  
Roller Bearing ◽  
Experimental Results ◽  
Line Contact ◽  
Contact Deformation ◽  
Flat Plates ◽  
Special Cases ◽  
Analytical Work

Various line contact deformation equations used in roller bearing technology are analyzed. Many of these deformation equations, primarily involving plane strain, are shown to be special cases of a general equation derived in this paper. Experimental results are also presented to support the results of the analytical work.

scholarly journals A Generalized Method for Flat Plates Impact Detection and Location

2013 ◽  
Vol 543 ◽  
pp. 171-175
Author(s):  
Jose Andrés Somolinos ◽  
Rafael Morales ◽  
Carlos Morón ◽  
Alfonso Garcia
Keyword(s):  
Signal Processing ◽  
Flat Plate ◽  
Acoustic Signal ◽  
Experimental Results ◽  
Piezoelectric Sensors ◽  
Experimental Setup ◽  
Flat Plates ◽  
Impact Detection ◽  
Timing Difference

In the last years, many analyses from acoustic signal processing have been used for different applications. In most cases, these sensor systems are based on the determination of times of flight for signals from every transducer. This paper presents a flat plate generalization method for impact detection and location over linear links or bars-based structures. The use of three piezoelectric sensors allow to achieve the position and impact time while the use of additional sensors lets cover a larger area of detection and avoid wrong timing difference measurements. An experimental setup and some experimental results are briefly presented.

Experimental Study of Multiple Air Jets Impinging a Moving Flat Plate

2020 ◽  
Author(s):  
Flavia Barbosa ◽  
Senhorinha Teixeira ◽  
Carlos Costa ◽  
Filipe Marques ◽  
José Carlos Teixeira
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Jet Impingement ◽  
Plate Motion ◽  
Test Facility ◽  
Flat Plates ◽  
Target Plate ◽  
Wall Jets ◽  
Air Jets ◽  
Flow Interactions

Abstract The motion of the target plate is important in some industrial applications which apply multiple jet impingement, such as reflow soldering, drying and food processing. Multiple jet impingement is widely used due to its ability to generate high heat transfer rates over large and complex areas. This convective process is characterized by several flow interactions essentially due to adjacent jets mixing prior the impingement, wall jets collision after the impingement, as well as crossflow interactions induced by the motion of the wall jets that flow through the exits of the domain. These interactions lead to strong flow recirculation, pressure gradients and boundary layer development. However, the complexity of the flow interactions is increased with the surface motion in confined space, due to the generation of strong shear regions. These interactions can induce problems and product defects due to complicated thermal behavior and non-uniform heating or cooling, being important to fully understand the process in order to reduce time and costs. This work addresses the experimental analysis of multiple air jets impinging on a moving flat plate. The experiments are conducted on a purpose-built test facility which has been commissioned, using a 2D-PIV system. Through this technique, the flow structure and velocity profiles will be analyzed in detail. The effects of the impinging plate motion on the resulting global and local velocity profile is compared with a static flat plate. The multiple jet configuration consists on air flowing through 14 circular nozzles, at a Reynolds number of 690 and 1,380. The experiments are conducted for a nozzle-to-plate distance of 8 and a jet-to-jet spacing of 2. The target plate motion remains constant throughout the experiments and equal to 0.03 m/s. The results are compared for both stationary and moving flat plates cases and express the increased complexity of the flow due to strong interaction between jets and the target surface, which affects the heat transfer performance. The results obtained experimentally are important to clearly define this complex flow and these data can be used in future works for numerical model validation.

scholarly journals Information and analytical support as an element of organization of economic security of entrepreneurial activity

2021 ◽  
pp. 77-81
Author(s):  
Є.В. Воронюк
Keyword(s):  
Organizational Structure ◽  
Organizational Support ◽  
Economic Security ◽  
Information Support ◽  
Entrepreneurial Activity ◽  
Analytical Work ◽  
Effective System ◽  
Analytical Research ◽  
Definition Of ◽  
Available Information

The article describes the importance of information and analytical support for the formation of organizational support for economic security of business. The stages and principles of formation of information-analytical support for creation of system of economic safety of the enterprise are analyzed. The connection and the nature of the influence of information-analytical activity and organizational support of economic security of the enterprise are investigated. It is important for the management of each organization to develop an individual mode of working with information, especially at the stage of its accumulation and analysis. Only a detailed and step-by-step definition of the process of working with information resources of various departments and officials increases the effectiveness of organizational support of economic security of the enterprise. The quality of analytical support is the basis for building an effective system of economic security of the enterprise and one of the key factors in its development. The harmonious combination of information-analytical work and the organization of economic security is a problem for the management of the business structure and requires a constant, operational study of the economic efficiency of the existing organizational structure.Adjusting the organizational structure directly affects the company's ability to withstand threats and risks from the external and internal environment. Modernity puts forward specific conditions for the economic security of the enterprise, especially given the deepening of the role and increase the amount of available information. The information array, which is freely available, is constantly replenished, which requires decision-makers to find new methods of information processing. The article analyzes the features of using the results of information support and analytical research to form an effective organizational structure of economic security of the enterprise. The study demonstrates the need for reliable and effective information and analytical support to improve the organizational support of economic security of the enterprise.

Vortex Shedding Analysis in the Wake of a Flat Plate at Low Incidence and Low Reynolds Number

2021 ◽  
Author(s):  
Bastav Borah ◽  
Anand Verma ◽  
Vinayak Kulkarni ◽  
Ujjwal K. Saha
Keyword(s):  
Reynolds Number ◽  
Velocity Field ◽  
Flat Plate ◽  
Vortex Shedding ◽  
Low Reynolds Number ◽  
General Tendency ◽  
Flat Plates ◽  
Trailing Edge ◽  
Low Reynolds ◽  
Low Incidence

Abstract Vortex shedding phenomenon leads to a number of different features such as flow induced vibrations, fluid mixing, heat transfer and noise generation. With respect to aerodynamic application, the intensity of vortex shedding and the size of vortices play an essential role in the generation of lift and drag forces on an airfoil. The flat plates are known to have a better lift-to-drag ratio than conventional airfoils at low Reynolds number (Re). A better understanding of the shedding behavior will help aerodynamicists to implement flat plates at low Re specific applications such as fixed-wing micro air vehicle (MAV). In the present study, the shedding of vortices in the wake of a flat plate at low incidence has been studied experimentally in a low-speed subsonic wind tunnel at a Re of 5 × 104. The velocity field in the wake of the plate is measured using a hot wire anemometer. These measurements are taken at specific points in the wake across the flow direction and above the suction side of the flat plate. The velocity field is found to oscillate with one dominant frequency of fluctuation. The Strouhal number (St), calculated from this frequency, is computed for different angles of attack (AoA). The shedding frequency of vortices from the trailing edge of the flat plate has a general tendency to increase with AoA. In this paper, the generation and subsequent shedding of leading edge and trailing edge vortices in the wake of a flat plate are discussed.

Small Rotationally Symmetric Deformations of Shallow Helicoidal Shells

1955 ◽  
Vol 22 (1) ◽  
pp. 31-34
Author(s):  
Eric Reissner
Keyword(s):  
Flat Plate ◽  
Plane Stress ◽  
General Property ◽  
Middle Surface ◽  
Circular Ring ◽  
Sample Problem ◽  
Flat Plates ◽  
Transverse Bending ◽  
Rotationally Symmetric

Abstract Known solutions for transverse bending and plane stress of flat circular ring plates are generalized so as to apply to shallow helicoidal shells. The pitch of the middle surface of the shell is responsible for a coupling of what would be separate problems of plane stress and transverse bending for flat plates. Explicit results are obtained for an important sample problem. A general property of helicoidal cantilever shells is stated. Criteria are obtained indicating, in terms of the parameters of the shell (a) the range of applicability of the results obtained, and (b) the range in which the shell behaves like a flat plate.

Prediction of Transition Region in Flow Over the Flat Plates

2009 ◽  
Author(s):  
Gh. Zahedi ◽  
S. H. Mansouri ◽  
M. Salmanzadeh
Keyword(s):  
Flow Field ◽  
Flat Plate ◽  
Transition Region ◽  
Transition Point ◽  
Eddy Viscosity ◽  
Model Comparison ◽  
Turbulent Regime ◽  
Transition Flow ◽  
Flat Plates ◽  
Turbulence Regime

A new model has been developed to predict the onset of transition from laminar to turbulent regime and also calculate the transition flow field. In developing the model, we have used the V2F turbulence model to predict the Reθ and velocity fluctuations, u′, at the onset of transition point, extracted from the same available experimental cases over a flat plate for several experimental cases. Then, we have correlated Reθ as a function of u′ at the transition point. This correlation has been used in conjunction with the V2F model to find the onset of transition point. The intermittency model has also been modified to calculate the probability of turbulence regime all over the flow field to improve the eddy viscosity calculated by V2F model. The model has been tested for different flat plate flows and the results compared with experimental data insuring the accuracy of the model. Comparison showed that the model is a powerful tool for prediction of transition onset and also transition region.

Friction Factor Behavior From Flat-Plate Tests of 12.15 mm Diameter Hole-Pattern Roughened Surfaces

2011 ◽  
Author(s):  
Thanesh Deva Asirvatham ◽  
Dara W. Childs ◽  
Stephen Phillips
Keyword(s):  
Reynolds Number ◽  
Flat Plate ◽  
Friction Factor ◽  
Dynamic Pressure ◽  
Reynolds Numbers ◽  
Stagnation Temperature ◽  
Flat Plates ◽  
Number Range ◽  
Current Test ◽  
Rough Plate

A flat-plate tester is used to measure the friction-factor behavior for a hole-pattern-roughened surface facing a smooth surface with compressed air as the medium. Measurements of mass flow rate, static pressure drop and stagnation temperature are carried out and used to find a combined (stator + rotor) Fanning friction factor value. In addition, dynamic pressure measurements are made at four axial locations at the bottom of individual holes of the rough plate and at facing locations in the smooth plate. The description of the test rig and instrumentation, and the procedure of testing and calculation are explained in detail in Kheireddin in 2009 and Childs et al. in 2010. Three hole-pattern flat-plates with a hole-pattern diameter of 12.15 mm were tested having depths of 0.9, 1.9, and 2.9 mm. Tests were done with clearances at 0.254, 0.381, and 0.653 mm, and inlet pressures of 56, 70 and 84 bar for a range of pressure ratios, yielding a Reynolds-number range of 100,000 to 800,000. The effects of Reynolds number, clearance, inlet pressure, and hole depth on friction factor are studied. The data are compared to friction factor values of three hole-pattern flat-plates with 3.175 mm diameter holes with hole depths of 1.9, 2.6, and 3.302 mm tested in the same rig described by Kheireddin in 2009. The test program was initiated mainly to investigate a “friction-factor jump” phenomenon cited by Ha et al. in 1992 in test results from a flat-plate tester using facing hole-pattern plates where, at elevated values of Reynolds numbers, the friction factor began to increase steadily with increasing Reynolds numbers. Friction-factor jump was not observed in any of the current test cases.

Measurements of Secondary Flows in a Rotating Duct

1972 ◽  
Vol 94 (4) ◽  
pp. 261-270 ◽  
Author(s):  
R. E. Wagner ◽  
H. R. Velkoff
Keyword(s):  
Experimental Study ◽  
Pressure Distribution ◽  
Cross Section ◽  
Experimental Work ◽  
Cross Flow ◽  
Secondary Flows ◽  
Working Fluid ◽  
Longitudinal Vortices ◽  
Developing Flow ◽  
Analytical Work

The paper presents a review of analytical and experimental work which has been done on flows in rotating ducts. It presents the results of an experimental study to measure the secondary flows predicted by the previous analytical work. A duct of approximately 3 ft in length with a cross section of 2 × 5 in. was rotated up to speeds of 300 rpm. Air was used as the working fluid. Static pressures, total pressures, and yaw angles were measured at selected points along the channel. The flow regime examined was the developing flow from the entrance to the exit of the channel. Examination of the data revealed the presence of two longitudinal vortices which extended the length of the channel. Pressure distribution across the height of the channel and across the width of the channel was obtained. The magnitude of the cross-flow velocities in the channel were determined and mapped. It was found that the data for various rotational speeds could be collapsed upon a single curve by dividing all data by the rotational speeds. The results of the experimental study provide solid verification for the hypothesis of longitudinal vortices in rotating ducts.

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