Plate Inclination Research Articles

Damage tolerance of CSM laminates subject to low velocity oblique impacts

This paper presents the results of an experimental investigation into the performance of CSM (Chopped Strand Mat) reinforced polyester laminates subject to low velocity impact at oblique angles. A fully instrumented test rig is used to assess the influence of imparted energy, impact force, and plate inclination with respect to surface indentation profiles, damage areas and micrographic evidence. A 25.4 mm diameter hemispherical-ended cylindrical steel impactor is employed to inflict impact damage in the laminates using the drop-weight test rig. The design facilitates impact energies up to 59 J and impact velocities in the range 0–5.42 ms −1. Plate inclinations are varied between 0 and 30 ° in 5 ° intervals. Simple expressions are formulated to predict the imparted energy and residual tensile strength in terms of experimentally determined variables. Residual tensile strengths are evaluated and shown to increase as plate inclination increases. The normal impact force is shown to be of greater importance than the tangential force in causing gross damage to specimen plates. For any given impactor strike energy, perpendicular impacts are shown to be more onerous than oblique impacts.

Effects of Weir Plate Inclination Angle on Flow-Induced Vibrations of Long-Span, Shell-Type Gates

Here we present detailed experimental results concerning flow-induced vibrations of long-span, shell-type gates in which the upstream gate face consists of vertical and inclined skin plates (also referred to as weir plates). Such shell-type gates possess two degrees of freedom, one each in the streamwise (horizontal) and vertical directions, due to bending flexibility in those two directions. The streamwise and vertical vibrations can become closely coupled with each other through the hydrodynamic forces acting on the weir plates, resulting in severe self-excited vibrations. A two-dimensional laboratory model of a long-span, shell-type gate was operated with underflow only (i.e., no overflow) at small gate openings with several different inclined weir plate geometries, ranging from a 17.5°to a 65°inclination angle (relative to the horizontal) for the inclined weir plate. By measuring the gate's vertical and horizontal displacements, it was possible to determine the vibration frequency, the excitation ratio (negative damping ratio) and the trajectories of gate motion. These results show that the inclination angle of the inclined weir plate angle plays a significant role in determining the gate's susceptibility to this type of dynamic instability. Long-span, shell-type gates with an inclined weir plate angle of about 60°relative to the horizontal were found to be the most unstable.

Effects of Weir Plate Inclination Angle on Flow-Induced Vibration of Long-Span, Shell-Type Gates.

Here we present detailed experimental results concerning flow-induced vibrations of long-span, shell-type gates in which the upstream gate face consists of vertical and inclined skin plates (also referred to as weir plates). Such shell-type gates possess two degrees-of-freedom, one each in the streamwise (horizontal) and vertical directions, due to bending flexibility in those two directions.The streamwise and vertical vibrations can become closely coupled with each other through the hydrodynamic forces acting on the weir plates, resulting in severe self excited vibrations. A two-dimensional laboratory model of a long-span, shell-type gate was operated with underflow only (i.e., no overflow) at small gate openings with several different inclined weir plate geometries, ranging from a 17.5°to a 65°inclination angle (relative to the horizontal) for the inclined weir plate. By measuring the gate's vertical and horizontal displacements, it was possible to determine the vibration frequency, the excitation ratio (negative damping ratio) and the trajectories of gate motion. These results show that inclination angle of the inclined weir plate angle plays a significant role in determining the gate's susceptibility to this type of dynamic instability. Long-span, shell-type gates with an inclined weir plate angle of about 60°relative to the horizontal were found to be the most unstable.

Taxonomic significance of vessel elements in the Tiliaceae

Internodal vessel elements were investigated in 7 genera and 27 species of the Tiliaceae with special reference to their taxonomic significance. On average, the longest vessel elements are 441 μm, recorded in Grewia asiatica and Triumfetta rhomboidea, and the shortest 78 μm, in Grewia microcos. The average maximum diameter is 79 μm in Corchorus aestuans, and the minimum 22 μm in Grewia microcos. The vessel elements are either cylindrical, spindle-shaped, column-, drum- or funnel-like, conical, clavate or oval. Perforation plates are simple in all the species studied, except in Grewia asiatica, where ephedroid-like perforation plates were recorded. There are usually two perforation plates in the majority of the members, rarely three or one. Adjacent wall thickening is commonly simple-pitted, but bordered, reticulate or scalariform pits have also been observed. Vessel elements vary in form and structure, number and inclination of perforation plates and side wall thickening. These characters are of taxonomic importance.

Three-dimensional structure of a supersonic jet impinging on an inclined plate

The flow structure of an underexpanded supersonic jet impinging on an inclined flat plate has been numerically investigated using a total-variation-diminishing scheme for the Euler equations. The impinging jet is characterized by many discontinuities, such as barrel shock, exhaust gas jet boundary, Mach disk, reflected shock, plate shock, subtail shock, contact surface, and sometimes a stagnation bubble. Furthermore, if the plate is inclined, the jet structure becomes three-dimensional and severely distorted. The effect of plate inclination has been investigated in the present paper by studying the formation of the asymmetric stagnation bubble and the magnitude and location of the maximum wall pressure. Comparison with the existing experimental results over a broad range of data sets on pressure and shock structure has led to the conclusion that the present inviscid numerical model can offer fairly good prediction of the impinging jet for moderate plate inclinations. The maximum wall pressure was found to be larger on the inclined plate than on the normal plate.

Vaginographic examination of the pelvic floor

In women with genital prolapse, damage to the pelvic floor muscles, fasciae, and ligaments leads to characteristic changes in the shape and position of the vagina. This observational study was undertaken to determine how these changes can be used to document damage to individual pelvic floor structures. Resting and straining radiographs in the standing position with barium in the vagina were made of 23 women with normal and 31 women with abnormal support, and correlated with anatomic studies of 23 cadavers. These studies demonstrate that the downward sagging of the upper vagina seen in frontal radiographs reflects a failure of the cardinal-uterosacral complex. Loss of the lateral indentations in the lower vagina indicates loss of the constricting effects of the levator ani. In lateral radiographs the levator plate's inclination can be measured. The distance between the pubic symphysis and anterior perineal body indicates the levator ani muscles' closure of the vagina. A line from the lower pubic symphysis to the ischial spine represents the location of the arcus tendineus fasciae pelvis. The distance between this line and the anterior vaginal wall indicates the status of the pubocervical fascia and its attachment to the arcus. With these observations, the vaginogram can be used to examine the status of the fascial and muscular supports of the vagina. It offers a research tool for the study of individual parts of the supportive system, and can be applied to such questions as the frequency of damage to muscles, fasciae or ligaments in recurrent prolapse.

Implications for experimental design from numerical modeling of natural convective heat transfer

ABSTRACT This paper discusses the important role that numerical modelling can play in providing detailed information on the structure of natural convective heat flows. This information, (velocity, temperature, streamline and heat flux fields throughout the entire flow), is generally unavailable from experimental studies due to limitations in the experimental techniques currently available. Computational results are presented and compared with experimental measurements for heated plates inside an isothermal enclosure, over a range of Rayleigh number, plate spacing, plate inclination and plate position. The paper also describes some potential dangers and misleading results that can emerge when computing these flows. Difficulties arising when performing experimental measurements on physical models of real equipment are also described.

Investigations on Mechanism of Salter-1-Fractures of the Greater Trochanter

This study aims at clarifying why the apophysis of the greater trochanter very rarely separates, in contrast to other apophyses of the hip region. The inclination and area measurement of the greater trochanteric growth plate and the mode of insertion of the muscles on the apophysis were analyzed on the basis of 16 anatomic femoral specimens from newborn to children of 14 years of age. The physiological muscle cross section Q of the muscles inserting at the greater trochanter was determined on 6 specimens. In a cross-sectional radiological study, carried out on 1350 hip joints of healthy children, the inclination of the greater trochanter growth plate was measured. The anatomical and radiological findings show that the nearly plane-shaped greater trochanter growth plate remains inclined at a 50 degree angle to the horizontal body line and is loaded from a diagonally craniolateral direction throughout the total growth period. The lateral surface of the apophysis is covered by a fibrous connection which joins the insertion areas of the gluteus medius, minimus and vastus lateralis muscles. The vastus lateralis muscle is intimately bound to the vastus intermedius muscle by fibrous tissue. According to the results of the physiological muscle cross sections these four muscle groups can form a counteracting muscle sling, which transforms the traction forces at the surface of the greater trochanter into pressure forces in line with a tension band effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Correction of coxa vara in childhood. The use of Pauwels' Y-shaped osteotomy

The long-term results following the correction of coxa vara by Pauwels' Y-shaped intertrochanteric osteotomy have been evaluated in 14 children. Ten of the children had unilateral hip disease and were otherwise normal while four had bilateral hip disease due to generalised skeletal dysplasias. In each case, the growth plate was vertical, the femoral head was displaced inferiorly and there were abnormalities in the metaphysis of the femoral neck. The results indicate that this osteotomy provides lasting correction of the deformity, regardless of the cause, as long as the inclination of the growth plate is corrected to 40 degrees or less and adequate support is provided for the metaphyseal defect and the displaced femoral head.

Effect of inclination of mirrors and intracavity plates on the polarization of CO2 laser radiation

Effect of inclination of mirrors and intracavity plates on the polarization of CO2 laser radiation

Gas desorption from falling liquid films in entrance region of inclined wetted-wall columns with an overflow-type distributor

The effect of the developing laminar flow of falling liquid films in inclined wetted-wall columns with an overflow-type distributor on the liquid-phase mass transfer was investigated theoretically and experimentally. The equation of motion for wave-free flow of the falling liquid film and the convective-diffusion equation for mass transfer in the falling liquid film, based on the boundary layer approximation, were solved simultaneously. A numerical solution for the liquid-phase Sherwood number was obtained as a function of the liquid-phase Reynolds and Schmidt numbers, the angle of inclination of the wetted-wall plate and the dimensionless distance in flow direction. Experiments were carried out on the desorption of oxygen from water into pure nitrogen. The experimental data were in fairly good agreement with the theoretical predictions in the entrance region of the falling liquid films.

Erratum: “Effect of Plate Inclination on Natural Convenction From a Plate to Its Cylindrical Enclosure” (Journal of Heat Transfer, 1986, 108, pp. 770–775)

Erratum: “Effect of Plate Inclination on Natural Convenction From a Plate to Its Cylindrical Enclosure” (Journal of Heat Transfer, 1986, 108, pp. 770–775)

Enhancement of forced convection heat transfer using turbulence promoters with clearance between heat transfer surface.

This study is a part of a research program whose objective is to determine an optimum way of enhancing forced convection heat transfer using turbulence promoters. Effectiveness of turbulence promoters with clearance between the heat transfer surface is tested. Flow friction and heat transfer coefficients are measured at Reynolds numbers ranged from 1.5×104 to 9×104. Inclination of the rib plate used as a promoter is also varied in addition to the variation of clearance. The result of performance evaluation suggests that a turbulence promoter with clearance and inclination shows a slight improvement of performance in the case where the clearance is small. A possible reason that such a type of turbulence promoter does not show much improvement in its performance characateristics may be the considerable reduction of the local heat transfer rate around the region where the separated flow reattaches.

Entrance region flow of falling liquid films in inclined wetted-wall columns with an overflow-type distributor.

Entrance region flow of falling liquid films in inclined wetted-wall columns with an overflow-type distributor was investigated theoretically and experimentally. The equations of motion based on boundary layer approximations were solved for the wave-free laminar flow of falling liquid films and a numerical solution was obtained for the dimensionless thickness of the falling liquid film, i.e., the Galileo number as a function of the liquid Reynolds number, the dimensionless distance in flow direction, and the angle of inclination of the wetted-wall plate. The liquid film thicknesses of water and aqueous sucrose solutions on inclined wetted-wall plates were measured and compared with theoretical predictions. The agreement between experimental data and theoretical predictions was fairly good in the wave-free entrance region of the falling liquid films.

Effect of Plate Inclination on Natural Convection From a Plate to Its Cylindrical Enclosure

Presented in this paper are the local and mean heat transfer coefficients for an inclined, thin, heated flat surface enclosed in a long isothermal cylinder. Holographic interferometry was used to identify variations of the convective coefficient on both sides of the plate. There are significant local variations when the surface is oriented at different angles to the gravitation vector. An overall heat transfer coefficient is identified which is influenced by opposing inclination effects on either side of the surface. Results are significantly different from those of a surface in an infinite environment due to the recirculation required by the enclosure geometry. The effects of inclination become minor at angles greater than 60 deg from the horizontal.

Evaporative convection in minute drops on a plate with temperature gradient

Thermal convection in a minute drop evaporating on a plate surface is visualized through two methods: solid suspension and laser shadowgraphy. The plate is partially heated to create a temperature field on the test site so that the Marangoni effect may be induced on the drop surface. Through altering plate inclination, the evaporating drop may stay at rest at the same spot or move on the plate. The observation of flow patterns in a stationary drop reveals that the presence of both surface tension and buoyancy forces lead to four distinct flow regimes in the drop with the buoyancy-driven convection on the warm side and the surface tension driven instability on the cold side. The effects of drop motion, liquid properties and air-liquid interfacial geometry on both the interfacial and internal flow structures are determined and the consequences of the evaporation rate are discussed.Convection evaporatoire pour des petites gouttes sur une plaque avec gradient de temperature of the evaporation rate are discussed.

被覆溶接棒の偏心が溶着に及ぼす影響

By means of eccentrically covered electrode of ilmenite type and cellulose type coating which has a definite outer diameter and various eccentricities relating to the core wire of a given diameter, the fusion penetration phenomena of stringer bead made on base metal plate in the flat position welding and fire cracker welding were investigated. Furthermore up-slope welding in the flat position were investigated under variously inclined base plate.The results obtained are summarized as follows:(1) Flat position welding; a) The shape of penetration becomes Central Penetration Type when the coating thickness is thinner at front side of the electrode travelling and comparatively low arc voltage in the flat position.(2) Fire cracker welding; a) When the thicker coating thickness are facing to the base plate, the arc is blown up so that the sound weld can't be made easily. When to some extent the arc is directed to the base plate the appearance of weld bead becomes smoother.(3) Up-slope welding; a) The most favourable inclination of the base plate for practical use occurs at θ = γ, θ being the angle of arc jet, γ the inclination angle of base plate. b) The base plate of large inclination may be successfully welded with electrode of large eccentricity, even when a satisfactory welding can't be achieved by electrode of small eccentricity.

Static drop on an inclined plate: Analysis by the finite element method

The shapes of drops of given volume and density in contact with an inclined plate over a circular wetted area are found from the Young—Laplace equation by means of the finite element method. Contact angle variations around the contact circles at mechanical equilibrium are determined, and the maximum advanced and minimum receded contact angles are calculated as functions of plate inclination and drop volume. The largest inclination at which a drop of given volume can remain static is found. An approximate force balance used by previous investigators is evaluated and Larkin's one-parameter family of solutions that satisfy no simple boundary condition is discussed.

Remodelling after distal forearm fractures in children. I. The effect of residual angulation on the spatial orientation of the epiphyseal plates.

The effect of residual fracture angulation on the distal radial and ulnar epiphyseal plates was studied in children aged 1 to 15 years. Thirty-eight fractures located in the distal fifth of the forearm bones were observed for 1 to 25 months after the fractures had healed. The forearms were examined radiographically on two to five occasions and the inclinations of the epiphyseal plates in relation to the long axis of the proximal fragments were measured. The results showed that an abnormal inclination of the epiphyseal plate after healing of a distal forearm fracture induced an alteration of growth in the epiphyseal plate. The redistribution of growth tended to correct the abnormal inclination. The rate of correction followed an exponential course. The age of the child at the time of the fracture and the distance from the fracture to the epiphyseal plate did not influence the capacity for correction.

Effect of Polymer Additives on the Process of Transition

The process of transition from laminar to turbulent flow on a flat plate in the presence of drag-reducing polymer additives has been investigated. In particular, the effect of polymer concentration and plate inclination on the formation of turbulent spots and their subsequent growth has been studied. It is observed that polymer addition causes a delay in both onset of turbulence and complete transition. The turbulent spots are seen to move at a lower velocity in the presence of the polymer additives. Further, the pressure gradient affects the transition in polymer solutions in the same way that it does in pure water.