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.

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 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.

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.

scholarly journals Stress Analysis of HCPB BB under Ex-Vessel LOCA Condition

2021 ◽  
Vol 2108 (1) ◽  
pp. 012088
Author(s):  
Mengdi Dai ◽  
Xiaomo Wang
Keyword(s):  
Stress Distribution ◽  
Stress Field ◽  
Stress Analysis ◽  
Cross Section ◽  
Maximum Stress ◽  
Fusion Reactor ◽  
Vacuum Vessel ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Size Dimension

Abstract Helium Cooled Pebble Bed Breeding Blanket (HCPB BB) is a kind of concept for the European demonstration fusion reactor (DEMO). The blanket attachment system plays an important role in the mechanical connection of the BB and vacuum vessel. Typically, the mechanical and thermal loads should meet the requirement to avoid collapse of the system with off-normal conditions, e.g., under ex-vessel Loss of Coolant Accident (LOCA. This paper investigates the loading requirement corresponding to the maximum stress that can sustain to avoid the LOCA condition. Firstly, a model of the BB is constructed using SolidWorks. Then, stress analysis is carried out based on the cross section of the blanket. Through simulation, the critical condition for the LOCA case and the maximum stress value for the model are obtained. According to the relevant size dimension from the reference, the blanket’s cross section is drawn, and one can get the stress field under the ex-vessel LOCA through stress analysis. The stress distribution under the ex-vessel LOCA condition is simulated to find out the maximum stress field that the blanket can sustain through this paper. The significance is to predict the possible conditions leading to an accident and find possible methods to avoid them.

Bending of a Thin Cylindrical Shell Subjected to a Line Load Around a Circumference

1961 ◽  
Vol 28 (3) ◽  
pp. 427-433 ◽  
Author(s):  
H. R. Meck
Keyword(s):  
Cylindrical Shell ◽  
Circular Cylindrical Shell ◽  
Thin Cylindrical Shell ◽  
Radial Line ◽  
Eighth Order ◽  
Line Load ◽  
Bending Stresses ◽  
Center Section ◽  
Fourth Order Equations ◽  
Thin Shell Theory

An analysis is developed for bending of a thin circular cylindrical shell under a varying radial line load distributed around the circumference at the center section. The problem is solved by reducing the eighth-order differential equation of thin-shell theory to two approximate fourth-order equations. Deflections, bending stresses, and membrane stresses are evaluated. Both simply supported and clamped ends are considered.

Study on the Stress Distribution of the Piston Rod Fillet Based on the Nonlinear Finite Element Method

2014 ◽  
Vol 1070-1072 ◽  
pp. 1848-1851
Author(s):  
Xiao Yu Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Cross Section ◽  
Maximum Stress ◽  
Nonlinear Finite Element ◽  
Nonlinear Finite Element Method ◽  
Fillet Radius ◽  
Element Method

Because of discontinuity of the shape, the piston rod of rapping device is liable to occur stress concentration phenomenon, leading to fracture of the piston rod. At work, the maximum stress of piston rod which took place in the cross section of the geometric mutations varied with the change of the fillet radius, under the same load, it analyzed the influence of different fillet radius on fracture of the piston rod via ANSYS/LS-DYNA finite element. The results showed that it can meet the requirements when the fillet radius was 5 mm.

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

A tilting high temperature gas reaction chamber for the JEM 7A T.E.M.

1978 ◽  
Vol 36 (1) ◽  
pp. 70-71
Author(s):  
Brian L. Rhoades
Keyword(s):  
Cross Section ◽  
Reaction Chamber ◽  
Objective Lens ◽  
Reduced Cross Section ◽  
Cross Sectional ◽  
Structural Investigations ◽  
Transmission Electron ◽  
Dynamic Experiments ◽  
Successful Design ◽  
Thermocouple Junction

A gas reaction chamber has been designed and constructed for the JEM 7A transmission electron microscope which is based on a notably successful design by Hashimoto et. al. but which provides specimen tilting facilities of ± 15° aboutany axis in the plane of the specimen.It has been difficult to provide tilting facilities on environmental chambers for 100 kV microscopes owing to the fundamental lack of available space within the objective lens and the scope of structural investigations possible during dynamic experiments has been limited with previous specimen chambers not possessing this facility.A cross sectional diagram of the specimen chamber is shown in figure 1. The specimen is placed on a platinum ribbon which is mounted on a mica ring of the type shown in figure 2. The ribbon is heated by direct current, and a thermocouple junction spot welded to the section of the ribbon of reduced cross section enables temperature measurement at the point where localised heating occurs.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

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