Reinforced Elliptical Holes in Stressed Plates

1957 ◽  
Vol 61 (562) ◽  
pp. 688-693 ◽  
Author(s):  
Raymond Hicks
Keyword(s):  
Stress Distribution ◽  
Cross Section ◽  
Maximum Stress ◽  
Elliptical Hole ◽  
Pressure Vessels ◽  
Stress System ◽  
Sectional Area ◽  
Principal Stresses ◽  
Cross Sectional ◽  
Elliptical Holes

SummaryThis paper considers the problem of a reinforced elliptical hole in a plate under the action of a principal stress system of the type found in cylindrical and ellipsoidal pressure vessels. That is, stress systems in which the ratio of the principal stresses is not greater than two to one. It is shown that when the ratio of the major and minor axes of the ellipse can be chosen arbitrarily, practical reinforcements can be designed to give a maximum stress around the hole which is only slightly greater than the maximum stress in a similarly loaded plate with no hole. General expressions are obtained for the stress distribution in the plate around the hole, for the stress acting on a normal cross section of the reinforcement, and for the cross-sectional area of a reinforcement which gives a small stress concentration. These are used to find the variation in the stress distribution around the hole due to reinforcements having different cross-sectional areas when the applied principal stresses are in the ratio of two to one and Poisson's ratio for the material of the plate and reinforcement has practical values.

scholarly journals Numerical Simulation on Mechanical Strength of a Wooden Golf Stick

2018 ◽  
Vol 2 (1) ◽  
pp. 13
Author(s):  
Darianto Darianto ◽  
Bobby Umroh ◽  
Amrinsyah Amrinsyah ◽  
Zulfikar Zulfikar
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Impact Load ◽  
Golf Club ◽  
Stress And Strain ◽  
Sectional Area ◽  
Cross Sectional ◽  
Swing Speed ◽  
The Impact

In general, golf players only know the techniques used in Golf games, but do not know the golf sticks response that occurs when the ball is hit. Referred to as response is the stress and strain that arises from the impact load that occurs when the hitting member touches the ball. The objectives of this research are: (a) to analyze golf sticks response when impact occurs, and (2) to know the stress distribution that occurs in golf sticks. The golf stick design in this study uses the autodesk inventor software. The material used is Titanium for head stick and Graphite for stick rod. The basic principle of this study is based on simple swing pendulum method. The variables that will be used for simulation are: swing speed, that is difference between start and end speed, that is Δv = 272,2 m / s, impact time, which is the time when the ball touches the batter Δt = 0.0005 seconds, the volume of the head of the stick Vo = 96,727 mm<sup>3</sup>, the cross-sectional area of the stick A = 63,504 mm<sup>2</sup>, the head mass of the sticks ρ = 4620 kg / m<sup>3</sup>, and the modulus of titanium elasticity 9.6 e +10 Pa. From the simulation result on the surface of the golf club hitter is obtained as follows: σ<sub>max</sub> = 2.1231e +10 Pa at 1.231e-06 s, e<sub>max</sub> = 0.22115 m / m at 1.231e-06 s, and the maximum stress and strain is located in the area the connection between the stick and the head of the stick.

Stresses in Eccentric Stepwise Discontinuous Rings With Transition Section

1968 ◽  
Vol 12 (04) ◽  
pp. 269-278
Author(s):  
Arnold Allentuch ◽  
Joseph Kempner
Keyword(s):  
Stress Distribution ◽  
Cross Section ◽  
Maximum Stress ◽  
Circular Cylindrical Shell ◽  
Radial Line ◽  
Cross Sectional ◽  
Line Load ◽  
Transition Section ◽  
Parameter Values ◽  
Interaction Problem

The stress distribution in a ring of nonuniform cross section under the action of a uniform radial line load is obtained. The solution is an approximation to the exact interaction problem of a reinforced circular cylindrical shell under hydrostatic pressure. The ring is fabricated in three segments; one segment, whose cross-sectional area varies according to a power function, connects two uniform segments. By a proper choice of parameter values the ring geometry can be reduced to two segments, one of uniform depth, the other of continuously varying depth. Several sets of parameters are chosen for numerical calculations. Within these sets only the length of the transition section changes. Thus an appraisal of the importance of the transition section in reducing the maximum stress is made. The stress distribution in a frame with different lengths of transition section is obtained.

Stresses Around Reinforced Elliptical Holes, with Applications to Pressure Cabin Windows

1959 ◽  
Vol 10 (4) ◽  
pp. 373-400 ◽  
Author(s):  
W. H. Wittrick
Keyword(s):  
Stress Distribution ◽  
Analytical Solution ◽  
Arbitrary Constant ◽  
Elliptical Hole ◽  
Stress System ◽  
Complex Variable Methods ◽  
Wide Range ◽  
Plane Sheet ◽  
Elliptical Holes ◽  
Different Shapes

An analytical solution, using complex variable methods, is given for the problem of the stress distribution due to an elliptical hole, reinforced around its boundary, in a plane sheet subjected at infinity either to an arbitrary constant stress system or to a bending type stress system. Numerical results were obtained for a wide range of parameters, including three different shapes of ellipse, and ten different amounts of reinforcement. Poisson's ratio was assumed to be 1/3.

Online Monitoring of Functional Electrical Properties in Aerosol Jet Printing Additive Manufacturing Process Using Shape-From-Shading Image Analysis

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Roozbeh (Ross) Salary ◽  
Jack P. Lombardi ◽  
Prahalad K. Rao ◽  
Mark D. Poliks
Keyword(s):  
Cross Section ◽  
Electrical Resistance ◽  
Online Monitoring ◽  
Shape From Shading ◽  
Sectional Area ◽  
Cross Sectional ◽  
Jet Printing ◽  
The Cross ◽  
Aerosol Jet Printing ◽  
Line Resistance

The goal of this research is online monitoring of functional electrical properties, e.g., resistance, of electronic devices made using aerosol jet printing (AJP) additive manufacturing (AM) process. In pursuit of this goal, the objective is to recover the cross-sectional profile of AJP-deposited electronic traces (called lines) through shape-from-shading (SfS) analysis of their online images. The aim is to use the SfS-derived cross-sectional profiles to predict the electrical resistance of the lines. An accurate characterization of the cross section is essential for monitoring the device resistance and other functional properties. For instance, as per Ohm’s law, the electrical resistance of a conductor is inversely proportional to its cross-sectional area (CSA). The central hypothesis is that the electrical resistance of an AJP-deposited line estimated online and in situ from its SfS-derived cross-sectional area is within 20% of its offline measurement. To test this hypothesis, silver nanoparticle lines were deposited using an Optomec AJ-300 printer at varying sheath gas flow rate (ShGFR) conditions. The four-point probes method, known as Kelvin sensing, was used to measure the resistance of the printed structures offline. Images of the lines were acquired online using a charge-coupled device (CCD) camera mounted coaxial to the deposition nozzle of the printer. To recover the cross-sectional profiles from the online images, three different SfS techniques were tested: Horn’s method, Pentland’s method, and Shah’s method. Optical profilometry was used to validate the SfS cross section estimates. Shah’s method was found to have the highest fidelity among the three SfS approaches tested. Line resistance was predicted as a function of ShGFR based on the SfS-estimates of line cross section using Shah’s method. The online SfS-derived line resistance was found to be within 20% of offline resistance measurements done using the Kelvin sensing technique.

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 Mechanical Compromise of Partially Lacerated Flexor Tendons

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Jaclyn Kondratko ◽  
Sarah Duenwald-Kuehl ◽  
Roderic Lakes ◽  
Ray Vanderby
Keyword(s):  
Stress Concentration ◽  
Cross Section ◽  
Viscoelastic Properties ◽  
Maximum Stress ◽  
Surgical Repair ◽  
Cross Sectional ◽  
Flexor Tendons ◽  
Percent Loss ◽  
Before And After ◽  
Insight Into

Tendons function to transmit loads from muscle to move and stabilize joints and absorb impacts. Functionality of lacerated tendons is diminished, however clinical practice often considers surgical repair only after 50% or more of the tendon is lacerated, the “50% rule.” Few studies provide mechanical insight into the 50% rule. In this study cyclic and static stress relaxation tests were performed on porcine flexor tendons before and after a 0.5, 1.0, 2.0, or 2.75 mm deep transverse, midsubstance laceration. Elastic and viscoelastic properties, such as maximum stress, change in stress throughout each test, and stiffness, were measured and compared pre- and post-laceration. Nominal stress and stiffness parameters decreased, albeit disproportionately in magnitude, with increasing percent loss of cross-sectional area. Conversely, mean stress at the residual area (determined using remaining intact area at the laceration cross section) exhibited a marked increase in stress concentration beginning at 47.2% laceration using both specified load and constant strain analyses. The marked increase in stress concentration beginning near 50% laceration provides mechanical insight into the 50% rule. Additionally, a drastic decrease in viscoelastic stress parameters after only an 8.2% laceration suggests that time-dependent mechanisms protecting tissues during impact loadings are highly compromised regardless of laceration size.

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.

Efficiencies for Partially Wetted Spine Fins: Uniform Cross Section, Conical, Concave Parabolic, and Convex Parabolic Spines

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Worachest Pirompugd ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Cross Section ◽  
Transfer Rate ◽  
Approximate Equation ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fin Efficiency ◽  
Conduction Heat Transfer ◽  
Uniform Cross Section

In this study, efficiencies for partially wetted fins for the uniform cross section spine, conical spine, concave parabolic spine, and convex parabolic spine are presented using an analytical method. Depending on the set of boundary conditions, there are two methods for deriving the efficiencies of partially wet fins for each spine. The eight equations for fin efficiencies were investigated. Fin efficiency is a function of the length of the dry portion. Thus, the equations for calculating the length of the dry portion are also presented. The findings indicate that a larger cross-sectional fin results in a higher conduction heat transfer rate. Contrarily, the fin efficiency is lower. This is different from the longitudinal fin, for which the trend lines of heat transfer rate and fin efficiency are the same. This converse relationship is due to the effect of the ratio of the cross-sectional area to the surface area. Moreover, partially wet fin efficiencies decrease with increased relative humidity. For convenience, the approximate equation for efficiencies for partially wet fins, which is derived from the equations for fully wet and fully dry fin efficiencies, is also presented.

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.

A Method to Estimate Cross-Sectional Stress Distributions on Reinforced Nozzle Corners Under Internal Pressure

2019 ◽  
Author(s):  
Chang-Sik Oh ◽  
Tae-Kwang Song ◽  
Sang-Min Lee
Keyword(s):  
Internal Pressure ◽  
Cross Section ◽  
Pressure Vessels ◽  
Fe Analysis ◽  
Stress Distributions ◽  
Corner Crack ◽  
Cross Sectional ◽  
Simple Method ◽  
Geometric Variables ◽  
Good Agreement

Abstract Stress distribution through the nozzle corner cross-section may be required to calculate stress intensity factor (SIF) for a nozzle corner crack in accordance with ASME Section XI Nonmandatory Appendix G. This paper proposes a simple method to predict nozzle corner cross-section stress distributions on reinforced nozzle corners of pressure vessels under internal pressure. This method includes simplified equations for predicting stresses on the inner surfaces of the nozzle corner region. These equations are expressed in terms of stress concentration factor (SCF) and geometric variables. Approximate SCF solutions for the reinforced nozzle corners are also proposed. Stress distributions using the proposed method are compared with finite element (FE) analysis results of nozzle-vessel intersections of various geometric dimensions, and agreements are quite good within postulated crack depths. Furthermore, SIFs calculated from the estimated stress distributions in accordance with ASME Section XI Nonmandatory Appendix G are compared with those from the FE results, showing good agreement.

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