Truncated Cone Research Articles

Generated Force and Deformation at a Conical End of Soft Magnetic Iron Bars due to Impact.

In designing machine parts or structures which should withstand an impact load, it is fundamentally important to know the dynamic deformation of the materials at its contact part and the impulsive force generated at that part. The deformed shape at the contact part and the generated impulsive force have been measured when a Soft Magnetic Iron bar collides axially, perpendicularly against a devised sensing plate. It was found that a new truncated cone was formed at the contact end and that the conical angle of the cone depended only on the conical angle of the former cone before the collision. It was also confirmed that the generated mean stress on the boundary plane between the deformed part and the undeformed part at the impact end was constant. By comparing experimental results with calculated results using the theoretical relation proposed in previous paper, the effectiveness of the theoretical relation for estimating the impulsive force for Soft Magnetic Iron Bars is confirmed.

4841249 Truncated cone shaped surface resonator for nuclear magnetic resonance tomography : Wilhel Duerr, Hartwig Ingwersen, Norbert Krause, Ralph Oppelt, Erlangen, Federal Republic of Germany assigned to Siemens Aktiengesellschaft

4841249 Truncated cone shaped surface resonator for nuclear magnetic resonance tomography : Wilhel Duerr, Hartwig Ingwersen, Norbert Krause, Ralph Oppelt, Erlangen, Federal Republic of Germany assigned to Siemens Aktiengesellschaft

Strength of structural elements made of glass-reinforced carbon in compression

Experimental data for the structural strength in axial compression and bending of monolithic composite specimens of glass-reinforced carbon grade SU-2000 and also the supporting capacity of multilayer structural elements having the shape of a bar or hollow truncated cone loaded by an axial force and external hydrostatic pressure are analyzed.

Three-dimensional response analysis of a hollow truncated cone.

The three-dimensional dynamic response of an internally damped hollow truncated cone translationally or rotationally driven at the base is determined by the Ritz method. With the displacements of the hollow truncated cone assumed in the forms of algebraic polynomials, the dynamic energies of the body are evaluated on the basis of the three-dimensional theory of elasticity, and the equations of motion of the body are determined from the Lagrange equations. By the application of the method, the dynamic response curves are calculated numerically for the hollow truncated cones driven by a sinusoidally varying axial or transverse deflection, or angular rotation at the clamped base, together with the natural frequencies and the mode shapes, and the results are presented in some figures.

Distribution of Intramembrane Particles and Its Changes during the Acrosome Reaction in Spermatozoa of the Japanese Abalone: (abalone sperm/acrosome reaction/membrane particle/freeze-fracture).

The distribution of intramembrane particles in the plasma and acrosomal membranes of sperm of the Japanese abalone, Haliotis discus, and its changes during the acrosome reaction were studied by the freeze-fracture replica technique. The P face of the plasma membrane covering the acrosome has sparse membrane particles except in the apical region, which includes the trigger and 'truncated cone' regions. Large particles with an average diameter of 10 nm are located in this apical region. The E face of the plasma membrane has only a few particles. On the outer acrosomal membrane, many particles are randomly distributed throughout the P face, but only a small number of particles are found on the E face. Numerous particles on the P face of the inner acrosomal membrane show a regular arrangement as a dense lattice or with a concentric circular pattern. The initial change in the acrosome reaction is clearance of membrane particles from both the P and E faces of the plasma and outer acrosomal membranes around the apical region, where fusion of the two membranes occurs. As the acrosomal process elongates, the dense arrangement of particles on the inner acrosomal membrane changes via a loose lattice arrangement to a patchy distribution with particle-free areas. Then the arrangement is further disorganized becoming a sparse, random distribution.

アルミ棒の凸状端変形挙動と発生衝撃力 実験および衝撃力を予測する簡便式

In studying the dynamic behavior of a body under impulsive loading, it may be fundamentally important to analyze elastic/plastic deformation at a contact part and to analyze the impulsive force generated at that part. So, in this study, the deformation at the contact part and the generated impulsive force were measured through the experiments in which aluminum bars collided axially, perpendicularly against the impact surface of a sensing plate which had been devised by one of the authors. The aluminum bars used had contact ends in the shape of the circular cone or truncated cone (frustum). The impact velocity of the bars was varied from 0 to about 11m/s. It was found through the experiments that a new truncated cone was formed at the contact end, and that the conical angle of the cone depended only on the conical angle of the former cone before the collision. It was also confirmed that the generated mean stress of the boundary plane between the deformed part and the undeformed part at the impact end was constant independently of the shape of the cone and of the impact velocity.A simple and practical formula was derived with which the impact force generated at the contact part can be estimated for the collision of a body having a convex surface against a rigid wall, and a good agreement with the experimetnal results was obtained.

Effect of Rheological Properties of Cement Pastes on Workability of Mortars

Abstract With a view to establishing a relationship between the rheological behavior of cement pastes with varying water/cement (W/C) ratios and the workability of different mortars, rotoviscosimetric (hysteresis cycle and transient) tests were conducted on the pastes, and slump and flow tests were performed on the mortars. Yield value was taken as the parameter representative of paste rheology. Because of the absence of a standardized slump test for mortars, a special truncated cone was designed. The τo values obtained in the rotoviscosimetric tests are represented as a function of the W/C ratio; and the slump and flow tests are represented as a function of the aggregate/cement (A/C) ratio. The possibility of correlating τo of the pastes with the results of slump and flow tests conducted on mortars is then illustrated. A dimensionless parameter is proposed, which contains both the terms of mortar composition and the parameter τo of the pastes, with which workability measurements can be unequivocally correlated. By this means the workability of a mortar can be derived from the knowledge of the rheological properties of the paste of given composition used in its manufacture. Finally, the advantage of introducing, in addition to the other elements characterizing the cement, a rheological factor for deriving the workability, however, expressed, is discussed.

The Three-Dimensional Hollow or Solid Truncated Cone Under Axisymmetric Torsionless End Loading

The Saint-Venant problems of solid or hollow truncated cone are investigated under axisymmetric torsionless end loading with the ruled sides being free from stress. Total-stress problems are formulated in terms of a vector partial differential equation whose component variables are stresses or of stress-type. A biorthogonality condition is derived which permits the numerical solution of boundary-value problems, and the results of a sample application of the method are presented.

Impedance Calculations for Oboe and Oboe-like Structures

A scheme has been developed for calculating the input impedance at the reed end of woodwind structures. The scheme is based on representing the bore and fingerholes of an instrument with lossy cylindrical sections. The log of the impedance is calculated and plotted at 10-Hz intervals over the range from 0 to 3000 Hz for each specified fingering of the instrument. Impedance curves have been calculated for the following oboe-like bores: (1) simple truncated cone, (2) smooth bores of one and five conical joints, (3) bores with discontinuities at the reed staple, (4) oboe with fingerholes and no losses, and (5) oboe with fingerholes and losses. Dr. Arthur Benade provided experimentally measured impedance curves for the oboe used as the basis of the calculations for case (5). The experimental and numerical results are compared and discussed.

Minimum Weight of Tapered Round Thin-Walled Columns

Abstract It is shown that the optimum wall thickness of a cylindrical round tube column is a function of load only and is independent of diameter. The optimum wall thickness of a tapered round thin-walled column is found to be constant along its length. The optimum shape of a tapered round thin-walled column is derived, being that column whose bending stress in the buckled state is constant along its length. The weight ratio of the optimum tapered column to an equal-strength optimum cylindrical column is found to be 0.8924. It is shown that a double truncated cone whose diameter ratio is in the range 0.35 ⩽ D1/D2 ⩽ 0.50 closely approaches the optimum column. If it is specified that no portion of the double truncated cone shall yield, then the weight advantage of the cone over the cylindrical column is rapidly lost as the stress in the cylindrical column approaches the yield stress. In the inelastic range the weight advantage of the tapered column will be less than in the elastic range.

ROOT SYSTEMS AND VOLUMES OF GIANT SEQUOIAS

THE REPORT of the fall of a giant redwood (Sequoia gigantea) in the Sequoia National Forest, 50 miles east of Visalia, California, in August, was the inspiration of a visit to obtain information as to the root-systems of these great trees and to give consideration to the facts upon which calculations of the amount of woody material in the two largest of these trees had been based.2 The uprooted tree had stood upon the eastern margin of Crescent Meadow, a bog about a hundred yards or less in width and a quarter of a mile long. It had fallen directly across the bog, as had many others of its kind in centuries past. This is to be connected with the fact that the tree recently fallen had suffered from fire which had burned the buttresses and roots at the margin of the bog, similar effects being noted in trees still standing and in the old prostrate trunks. These missing roots had occupied about one-third or one-fourth of the circumference of the base. High water level in the bog with accompanying softening of the soil was an additional factor in the overthrow of the tree; evidence of wind action was lacking. The upturned disk of soil held by the roots was about 30 ft. across with a thickness of less than 2 yds., which were also the dimensions of the pit resulting from the upheaval. The two largest roots were those issuing from the trunk on opposite sides and extending along the margins of the bog. About two dozen roots extended outward in the sector awav from the bog. These organs had been fractured about 10 to 12 ft. from the base of the tree. The stumps were visible on the rim of the upturned disk and the ends of the severed roots were to be seen on the walls of the pit resulting from the removal of the disk. No roots had penetrated the bottom of the pit. The horizontally extending roots encountered a competition of a close stand of other trees, and not much could be said as to their position in such a tangle. No evidence is available, however, to show that the roots of the redwoods ever penetrate deeply. A computation based on the above facts and upon two days' attention to other trees resulted in a conclusion that the volume of woody material in the roots-including the ones which had perished in the sector toward the bog-would not exceed 3,000 cu. ft. The trunk was 18 ft. in diameter, including the bark, 5 ft. from the surface of the soil. The top and branches had been much broken, but it was estimated that the total would have constituted a truncated cone 200 ft. in height with a diameter about 16 in. at the upper end.

Frost Difficulties and Experiences During the Past Winter

The Washington Suburban Sanitary District, a metropolitan area adjacent to the District of Columbia, within the State of Maryland, contains approximately 104 square miles and serves a population of 75,000 with water and sewer service. At the present time there are 335 miles of water mains, 260 miles of sewers, 16,400 water services, all metered, and 12,600 sewer connections. Water mains and services are laid in this District with a minimum cover of four feet and on all but a few services the meter is set in an outside housing at the property line. The system is 100 percent metered and the few remaining meters are set inside. The housing consists of a two-foot length of terra cotta pipe, 18 inches in diameter, upon which is placed a truncated cone of concrete, 18 inches high, 18 inches in diameter at the bottom and 15 inches in diameter at the

An Effect due to the Sudden Great Increase of Pressure

IN the course of some experiments on the mapping of the lines of electric force between two charged conductors, a remarkable effect, due to the sudden very great rise in pressure in the oil separating them, occurred. The conditions of the experiment necessitated the use of two pointed strips of tinfoil, separated by an interval of 1/16 in., laid on a sheet of glass with a drop of turpentine, to act as an insulator, between them. On this was laid a thin cover-glass, as used for covering objects when mounted for the microscope. Unintentionally the potential between the two tinfoil strips rose high enough to permit a spark to pass through the oil between them, and when this occurred a small piece was blown out of the centre of the cover-glass, being about 1/16 in. in diameter on the upper side and about half this on the lower, the piece of glass having the appearance of a small truncated cone. The cover-glass was only held down by the film of oil separating it from the strips of tinfoil; yet the fragment of glass was ejected with considerable force.