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Showing papers on "Deflection (engineering) published in 1975"


Journal ArticleDOI
TL;DR: In this article, a full-sized drilled shaft, or drilled pier, was constructed in the field in a stratum of stiff clay, and the foundation was instrumented so that bending moment could be measured at various depths.
Abstract: A full-sized drilled shaft, or drilled pier, was constructed in the field in a stratum of stiff clay. The foundation was instrumented so that bending moment could be measured at various depths. A series of lateral loads, both short-term static and cyclic, were applied to the foundation and families of bending moment curves, along with the boundary conditions at the groundline, were obtained. These data were analyzed and sets of curves were developed showing soil resistance p as a function of deflection y for various depths. Rational concepts concerning the behavior of soil around a laterally loaded deep foundation were employed, along with some empirical expressions, and equations are presented for the development of p-y curves for stiff clay, both for short-term static loading and for cyclic loading. The expressions were tested against available experiments and were found to yield satisfactory results.

391 citations


Journal ArticleDOI
TL;DR: In this paper, the central impact of a mass on a simply-supported laminated composite plate under initial stress is investigated, and the contact force and the dynamic response of the plate are obtained by solving a non-linear integral equation.
Abstract: : The central impact of a mass on a simply-supported laminated composite plate under initial stress is investigated. The contact force and the dynamic response of the plate are obtained by solving a non-linear integral equation. The energy transferred from the mass to the plate during impact is also obtained by use of a normalized contact force. It is found that a higher initial tensile stress elevates the maximum contact force, but reduces the contact time, the deflection, and the stresses. It is also noted that a higher tensile initial stress results in less energy transfer from the striking mass to the plate.

203 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented a finite element model with nodal degrees of freedom which can satisfy all the forced and natural boundary conditions of a Timoshenko beam, and the mass and stiffness matrices of the element were derived from kinetic and strain energies by assigning polynomial expressions for total deflection and bending slope.

143 citations


Patent
03 Jan 1975
TL;DR: In this paper, a flat cathode ray tube device is provided with a monolythic structure for x-y control of a matrix of electron beams, and a sandwiched deflection control structure has holes through which the beams may pass and forms a set of like mesh plates with offset shield provisions therein in the region of the path of each of said beams.
Abstract: A flat cathode ray tube device is provided with a monolythic structure for x-y control of a matrix of electron beams. A sandwiched deflection control structure has holes through which the beams may pass and forms a set of x-y control of the trajectory of the beams. A plurality of like mesh plates make up the control structure with offset shield provisions therein in the region of the path of each of said beams.

101 citations



Journal ArticleDOI
TL;DR: In this paper, a simplified method is presented for the analysis of framed-tube structures subjected to lateral loads, where rigidly jointed perimeter frame panels are replaced by equivalent orthotropic plates, whose properties are chosen to represent both the axial and shearing deformation characteristics of the frames.
Abstract: A simplified method is presented for the analysis of framed-tube structures subjected to lateral loads. The rigidly jointed perimeter frame panels are replaced by equivalent orthotropic plates, whose properties are chosen to represent both the axial and shearing deformation characteristics of the frames. The force and stress distributions in the panels are assumed to be represented with sufficient accuracy by polynomial series in the horizontal coordinates, the coefficients of the series being functions of the height only. The unknown functions are determined from the principle of least work. The influence of stiffer corner columns is included in the analysis. Closed-form solutions are presented for three standard load cases, a uniformly and a triangularly distributed load, and a point load at the top. Design curves are presented to enable solutions to be obtained rapidly.

63 citations



01 Dec 1975
TL;DR: In this article, an addendum to an experimental study of the large deformation of a cantilevered beam under a gravity tip load is presented, which adds higher quality and new data on the static twist and bending deflections of the beam.
Abstract: This is an addendum to an experimental study of the large deformation of a cantilevered beam under a gravity tip load. It adds higher quality and new data on the static twist and bending deflections of the beam. The experimental data are compared with a recently developed nonlinear structural theory. Agreement is good for deflections that are small compared to the beam span and has systematic deviations for larger deflections.

47 citations


Journal ArticleDOI
TL;DR: In this article, the effect of the mass of the springs is taken into account and the solution is formulated by the method of the Laplace transformations with respect to both time and space variables, which allows one to analyze all major performance characteristics in the system subjected to an arbitrarily distributed impulsive load.
Abstract: Dynamical behaviours of two beams connected with a set independent springs and subjected to an impulsive load are investigated taking the effect of the mass of springs into account. The solution is formulated by the method of the Laplace transformations with respect to both time and space variables, which allows one to analyze all the major performance characteristics in the system subjected to an arbitrarily distributed impulsive load. As a numerical example, the case of a concentrated half-sine impulsive force applied to the mid point of the upper beam is treated. It becomes evident that the amplitudes of deflection and bending moment in the beams decrease as the mass of the springs increases. The response curves are also compared with those for the mass-less springs of Wikler type. It is found that the similarities between the two responses diminish as the mass of the springs increases.

45 citations



Journal ArticleDOI
TL;DR: In this article, the decay in shear strength of reinforced concrete columns during earthquake loading was investigated by subjecting 12 column specimens to several reversals of loading to deflections larger than the yield deflection.
Abstract: The decay in shear strength of tied reinforced concrete columns during earthquake loading was investigated by subjecting 12 column specimens to several reversals of loading to deflections larger than the yield deflection. The principal variables of the test program were the axial load, the transverse reinforcement ratio, and the total deflection per cycle. The test specimens were able to develop the expected yield moment in the first quarter cycle and maintain that load for some inelastic deflection. However, the repetition of these deflections resulted in a decay in the strength of the member. Experimental data are used to examine the mechanism of strength decay, which is related to crushing and spalling of the shell concrete, yielding of the transverse reinforcement, and abrasive rubbing of concrete along inclined cracks. The results of this investigation indicate that the transverse reinforcement must be proportioned to carry the total shear required to develop the ultimate moment capacity of the column.

Journal ArticleDOI
TL;DR: In this paper, the optical properties of any combination of magnetic lenses and deflection yokes are described, including the most general case in which the lens and deflector fields may be physically superimposed.
Abstract: Methods are described for computing the optical properties of any combination of magnetic lenses and deflection yokes, including the most general case in which the lens and deflector fields may be physically superimposed. These techniques can handle either toroidal or saddle deflection yokes, wound on either nonmangetic of ferromagnetic formers, and can handle cases where the magnetic materials of the lenses directly influence the deflection fields. The basic program for calculating the properties of any given lens and deflection system has been combined with an optimization program, which systematically searches (subject to given physical constraints) for the arrangement which minimizes the deflection aberrations for any specified field size and aperture angle. Illustrative computed results are presented. It appears that conventional postlens single‐deflection systems can have better properties than conventional prelens double‐deflection systems. However, the performance of double‐deflection systems can be improved dramatically by placing the second yoke inside the lens and rotating it relative to the first yoke. An arrangement has been found, which, at the corners of a 5×5‐mm deflection field with 0.005‐rad aperture and 1 in 104 beam voltage ripple, produces a total aberration disk of 0.45 μm before dynamic corrections, or 0.15 μm after dynamic corrections. The properties of in‐lens single‐deflection systems have also been investigated. Such systems offer the possibility, for the same operating conditions as quoted above, of producing a total aberration disk of less than 0.2 μm after dynamic corrections. By introducing a ’’predeflection coil’’ before the main deflection coil, this value can be reduced to less than 0.1 μm.

Journal ArticleDOI
TL;DR: In this article, a projection lens with an integrated deflection yoke was developed as part of a probe-forming system for microfabrication, where a single yoke is located at the center of the polepiece gap for the purpose of minimizing deflection aberrations through compensation.
Abstract: A projection lens with an integrated deflection yoke has been developed as part of a probe‐forming system for microfabrication. A single yoke is located at the center of the polepiece gap for the purpose of minimizing deflection aberrations through compensation. The concept of a linked imaging trace generates a shaped beam at the target plane. The following performance parameters have been experimentally verified: a resolution of 20 000 lines per field, forming a square spot of 1.25×1.25 μm with an edge slope of 0.25 μm, over a field of 5×5 mm, and a spot current of 0.75 μA, which corresponds to a current density of 50 A/cm2.


Patent
04 Mar 1975
TL;DR: In this article, a cathode ray tube employing magnetic deflection coils for deflecting the electron beam in the horizontal and vertical directions, is corrected for the astigmatism error created by the non-uniform magnetic field which causes a predictable elliptical distortion of electron beam, through the use of two sets of correction coils mounted on a common annular magnetic core.
Abstract: A cathode ray tube employing magnetic deflection coils for deflecting the electron beam in the horizontal and vertical directions, is corrected for the astigmatism error created by the non-uniform magnetic deflection field which causes a predictable elliptical distortion of the electron beam, through the use of two sets of correction coils mounted on a common annular magnetic core located on the neck of the CRT, which distorts the electron beam prior to its entry into the magnetic deflection field in a manner that is complementary to the distortion created by the non-uniform magnetic deflection field. The excitation currents for the correction coils are derived from the horizontal (Vx) and vertical (Vy) beam deflection voltage signals, in such a manner that the excitation current for the first correction coil is proportional to Vx2 - Vy2, and the excitation for the second correction coil is proportional to 2.sup.. Vx.sup.. Vy.

Journal ArticleDOI
01 Jan 1975
TL;DR: In this paper, a transfer matrix approach was used for the stability analysis of rotating shafts, where the Lagrange equations of motion were applied to the bearing nonlinearity and the deformation energy and application of Lagrange's equations yielded the equation of motion.
Abstract: A general method is presented for the stability analysis of rotating shafts. A continuous rotor with any number of discontinuities and linear and nonlinear external forces has been modeled by way of a number of finite elements and degrees of freedom, and a number of comparison functions which have been chosen as the static deflection between nodes. A transfer matrix approach was used for this purpose. Kinetic and elastic deformation energy and application of Lagrange's equations yielded the equations of motion. Due to the bearing nonlinearity, these equations are nonlinear.

Patent
Larry G Lankford1, Whittle William R1
14 Jan 1975
TL;DR: A tool is inserted in the chuck of the automatic machine tool and the tool is driven over a deflection testing pad on the work support so that upon contact a first tool deflection force is measured as mentioned in this paper.
Abstract: A computer-controlled machine tool includes force deflection and tool-part contact sensors A tool is inserted in the chuck of the automatic machine tool and the tool is driven over a deflection testing pad on the work support so that upon contact a first tool deflection force is measured Then the tool is driven a small increment in the same direction to provide a second but greater tool deflection force in the same direction Then the computer calculates the differential value of the tool deflection force over the distance moved Also the error between estimated and actual tool diameter is calculated from the difference between the tool offset value used and the distance required for adjustment of the tool from a spaced starting position to contact with the pad

Journal ArticleDOI
TL;DR: In this paper, a laser beam is passed through the mixing zone of two liquids with different refractive indices, and the spatial variation of the refractive index, at different times during the mixing, can be determined from the observed deflection of the beam.
Abstract: In this simple experiment for an undergraduate laboratory a laser beam is passed through the mixing zone of two liquids with different refractive indices. The spatial variation of the refractive index, at different times during the mixing, can be determined from the observed deflection of the beam.

Patent
Delmar H. Ellis1
23 Oct 1975
TL;DR: In this article, a method and apparatus for measuring deflection of rotating members, such as the blades of a turbomachinery stage, is provided, where the rotating member is illuminated with a high intensity light beam such as a laser, at least one location upon the member where deflection is to be determined.
Abstract: A method and apparatus for measuring deflection of rotating members, such as the blades of a turbomachinery stage, are provided. The rotating member is illuminated with a high intensity light beam, such as a laser, at least one location upon the member where deflection is to be determined. Another location which serves as a reference is also illuminated in a similar manner. As the rotating member passes through the light beams, the light beams are reflected from reflective patches, thereby producing light impulses which are received by a light measuring device. The light pulses are converted to electrical impulses, the time increment between pulses being a function of the distance between the two locations and, thus, a measure of deflection. The dynamic component of blade-to-blade vibration is determined by comparing the time increments for a plurality of blades in the stage.

Patent
09 Jun 1975
TL;DR: In this paper, an optical scanner is disclosed for reading of optical bar codes of the type used for point-of-sale data acquisition, which provides a 3-line scan pattern adapted for omnidirectional reading of a bar code symbol.
Abstract: An optical scanner is disclosed for reading of optical bar codes of the type used for point-of-sale data acquisition. The optical scanner provides a 3-line scan pattern adapted for omnidirectional reading of a bar code symbol. Beam deflection means in the path of a single light beam is operative to deflect the beam about a deflection axis and to tilt the deflection axis from one deflection plane to another after each beam deflection thereby producing three trace segments in separate deflection planes. Trace orienting means in each of the deflection planes redirect the beams so that the trace segments are projected into the scanning field to produce 3-line pattern of trace segments.

Patent
15 Sep 1975
TL;DR: In this article, a movable frame with a female die on the top of a lower fixed frame and a male die at the bottom of a higher fixed frame is used to form an L-shaped beam.
Abstract: In a press for forming a long and narrow plate or strip of metal or synthetic resin into an elongated beam having an L-shaped section, of the type having a lower fixed frame provided with a female die on the top thereof and a hydraulically operated upper movable frame provided with a male die on the bottom thereof, a long space adjacent and parallel to the lower surface of the movable frame is provided in the movable frame. In the space are provided a plurality of small hydraulic deflection cylinders with pressure-fluid paths connected to the pressure-fluid paths of the main hydraulic cylinders to drive the movable frame. The space provided with a plurality of the small hydraulic deflection cylinders is so located that the center portion of the lower part of the movable frame is deflected counter to the deflection of the movable frame under press-forming load. When hydraulic pressure fluid is supplied to the main hydraulic cylinders to drive the movable frame for forming the plate by means of the dies fitted on the frames, the pressure fluid is also supplied to the plurality of the small hydraulic deflection cylinders in the space of the movable frame and the primary deflection of the frames under load is compensated for, so that a beam of L-shaped section free from convex or concave warp at its center portion is produced.

Journal ArticleDOI
TL;DR: In this paper, the structural properties of thin-walled cold-rolled stainless steel beams are investigated and the postbuckling behavior of thin compression elements stiffened along one or both unloaded edges by thin webs has been found to agree with Koiter's theory, with von Karman's relationship on effective width, as modified by Winter for carbon steel, as the lower bound.
Abstract: Results obtained from a research project dealing with the structural behavior of cold-formed members of cold-rolled stainless steel are presented. The distinctive mechanical properties include anisotropy, nonlinear and unsymmetrical stress-strain relationships in tension and compression, and the pronounced effect of cold working. The post-buckling behavior of thin compression elements stiffened along one or both unloaded edges by thin webs has been found to agree with Koiter’s theory, with von Karman’s relationship on effective width, as modified by Winter for carbon steel, as the lower bound. Using an iterative numerical procedure, the flexural strength and deflection of thin-walled cold-rolled stainless steel beams can be predicted accurately. A brief analysis on column behavior is also presented. Design methods taking into account the material characteristics and the post-buckling strength of the thin compression elements of these structural members are recommended.

Journal ArticleDOI
TL;DR: In this paper, a load-deflection analysis for a single pile with an elastic analysis of pile groups is presented, where the parameters most influencing the prediction are the soil modulus and the ultimate load of a pile in the group.
Abstract: A simple method of predicting the load-deflection behavior of a laterally loaded pile group is developed by combining a non linear load-deflection analysis for a single pile with an elastic analysis of pile groups. The parameters most influencing the prediction are the soil modulus and the ultimate lateral load of a pile in the group, H sub u. The soil modulus may be backfigured from a lateral load test on a single pile and a method of interpretation of the test is described. The lateral load capacity of an isolated single pile also may be estimated and by multiplying this value by a lateral group efficiency factor, H sub ur may be determined. A number of comparisons between the observed and predicted load-deflection behavior of model pile groups, show good agreement and suggest that the proposed method is capable of providing satisfactory load-deflection predictions for laterally loaded pile groups, provided appropriate values of soil modulus and H sub ur can be input into the analysis. /ASCE/


Journal ArticleDOI
TL;DR: In this paper, a general analytical and numerical procedure based on the linear theory is outlined for the elastic stress and deflection analysis of an arbitrary plane curved beam subjected to arbitrary static and dynamic loads.


Patent
19 Nov 1975
TL;DR: In this article, an electro-magnetically controllable beam deflection device for use in an optical system for deflecting a radiation beam obtained from a radiation source, in particular for using in video players is presented.
Abstract: An electro-magnetically controllable beam deflection device for use in an optical system for deflecting a radiation beam obtained from a radiation source, in particular for use in video players. The deflection means may for example comprise a pivoting mirror, or an assembly of a plano-concave and a plano-convex lens which with their concave and convex surfaces face each other, and can perform pivoting movements at a small distance from each other. The deflection means is connected to frame by means of an integrated plastic bearing component. The bearing component has a local portion of small cross-section which under the influence of the control forces exerted on the deflection means, is relatively readily deformable. This portion may for example take the form of an integral hinge or of a thin cylindrical portion.

Journal ArticleDOI
TL;DR: In this article, a finite element procedure was developed for the displacement and stress analysis of a homogeneous and isotropic inner tube mounted on a rim and in contact with a flat surface.
Abstract: A finite element procedure has been developed for the displacement and stress analysis of a homogeneous and isotropic inner tube mounted on a rim and in contact with a flat surface. The geometric nonlinear effect is accounted for by including the quadratic terms in the strain‐displacement equations. The nonlinear load‐displacement path is predicted by a linear incremental procedure. The procedure is first demonstrated by a large deflection analysis of a strip of a tire (a cable). The results are in good agreement with a known alternative solution. A homogeneous and isotropic inner tube is then pressurized and the displacements and stresses are found. The displacements are also found experimentally. Both results are in good agreement. Finally, the inner tube is mounted on a rim and pressed against a rigid flat surface. The resulting displacements and footprints are also measured experimentally. The computer results are shown to be in reasonable agreement with the experiment.

Patent
21 Aug 1975
TL;DR: In this paper, a joint in an arm of the person is subjected to a predetermined stress in a direction in which the joint moves, and the resulting deflection is measured, based on the position of the arm.
Abstract: Method and apparatus for testing the aptitude of a person for an activity requiring manual dexterity according to which a joint in an arm of the person is subjected to a predetermined stress in a direction in which the joint moves, and the resulting deflection is measured.

Patent
14 Oct 1975
TL;DR: In this paper, a color cathode ray tube including an electron gun means for projecting three electron beams in an in-line arrangement, there is provided deflection defocus correcting means which are disposed adjacent the side electron beams for neutralizing the deflectiondefocus of the side beam caused by the non-uniformity of deflection fields.
Abstract: In a color cathode ray tube including an electron gun means for projecting three electron beams in an in-line arrangement, there is provided deflection defocus correcting means which are disposed adjacent the side electron beams for neutralizing the deflection defocus of the side beam caused by the non-uniformity of the deflection fields.