scholarly journals Controlling Laminate Plate Elastic Behavior

10.14311/566 ◽  
2004 ◽  
Vol 44 (3) ◽  
Author(s):  
T. Mareš
Keyword(s):  
Fiber Orientation ◽  
Scalar Product ◽  
Lateral Displacement ◽  
Laminate Plate ◽  
Lateral Loading ◽  
Elastic Behavior ◽  
Central Plane ◽  
Simply Supported ◽  
Rectangular Laminate

This paper aims to express the relation of a measure of laminate plate stiffness with respect to the fiber orientation of its plies. The inverse of the scalar product of the lateral displacement of the central plane and lateral loading of the plate is the measure of laminate plate stiffness. In the case of a simply supported rectangular laminate plate this measure of stiffness is maximized, and the optimum orientation of its plies is searched.

Column Moment Demands from Orthogonal Beam Twisting

2018 ◽  
Vol 763 ◽  
pp. 259-269
Author(s):  
George Webb ◽  
Kanyakon Kosinanonth ◽  
Tushar Chaudhari ◽  
Saeid Alizadeh ◽  
Gregory A. MacRae
Keyword(s):  
Lateral Displacement ◽  
Frame Structure ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Element Analysis ◽  
Soft Storey ◽  
Simply Supported ◽  
Composite Frame ◽  
Explicit Consideration ◽  
Column Joint

Beam column joint subassemblies in steel moment frames often have simply-supported gravity beams framing into the joint in the perpendicular direction. When these subassemblies undergo lateral displacement, moments enter the column from the beams. Some of these moments are directly applied from the in-plane beam and slab stresses as they contact the column, and additional moments occur as the slab causes the perpendicular simply supported beams to twist. In most design codes around the world, no explicit consideration of these moments is performed even though they may increase the likelihood of column yielding and a soft-storey mechanism. This paper quantifies the magnitude of these perpendicular beam twisting moments in typical subassemblies using inelastic finite element analysis. It is shown that for beam-column-joint-slab subassemblies where the primary and secondary beams are fully welded to the column, the addition of slab effects significantly increases the total stiffness and strength of the composite frame structure. In addition to this, it is also shown the twisting moment demand of the secondary beams increased the frames strength by approximately 2% for an imposed drift of 5% for the subassembly investigated when no gap was provided between slab and the column. It was also shown the twisting moment demand of the secondary beams increased the frames strength by approximately 10% for a maximum imposed drift of 5% for the subassembly investigated when a gap was provided between the slab and the column.

scholarly journals Lateral Response of a Single Pile under Combined Axial and Lateral Cyclic Loading in Sandy Soil

2018 ◽  
Vol 4 (9) ◽  
pp. 1996 ◽  
Author(s):  
Muqdad Abdallah Kahribt ◽  
Jasim M. Abbas
Keyword(s):  
Lateral Displacement ◽  
Slenderness Ratio ◽  
Offshore Structures ◽  
Lateral Loading ◽  
Loading Conditions ◽  
Lateral Loads ◽  
Dense Sand ◽  
Lateral Response ◽  
Loading System ◽  
Vertical Displacements

According to practical situation, there have been limited investigations on the response of piles subjected to combined loadings especially when subjected to cyclic lateral loads. Those few studies led to contradictory results with regard to the effects of vertical loads on the lateral response of piles. Therefore, a series of experimental investigation into piles in dense sand subjected to combination of static vertical and cyclic lateral loading were conducted with instrumented model piles. The effect of the slenderness ratio (L/D) was also considered in this study (i.e. L/D= 25 and 40). In addition, a variety of two-way cyclic lateral loading conditions were applied to model piles using a mechanical loading system. One hundred cycles were used in each test to represent environmental loading such as offshore structures. It was found that under combined vertical and cyclic lateral loads the lateral displacement of piles decreased with an increase in vertical load whereas it causes large vertical displacements at all slenderness ratios. In addition, for all loading conditions the lateral, vertical (settlement and upward) displacements and bending moments increased as either the magnitude of cyclic load or the number of cycles increases. 

Three-Dimensional Numerical Analyses of Pile Response due to Braceded Excavation-Induced Lateral Soil Movement

2014 ◽  
Vol 580-583 ◽  
pp. 524-531 ◽  
Author(s):  
Lin Li ◽  
Xiao Xin Hu ◽  
Guang Hui Dong ◽  
Ju Liu
Keyword(s):  
Lateral Displacement ◽  
Three Dimensional ◽  
Bending Moment ◽  
Elastic Behavior ◽  
Pile Head ◽  
Soil Pressure ◽  
Soil Movement ◽  
Standard Problem ◽  
Modified Cam Clay ◽  
Pile Response

Using the explicit finite difference code FLAC3D, the behavior of pile adjacent to braced excavation is investigated. The Modified-cam clay constitutive model was employed to model the non-linear stress-strain soil behavior, and the pile was assumed to have linear elastic behavior. The interface model incorporated in FLAC3D code was used to simulate the soil/pile contact, The built-in 'fish' language was used to calculate the data demanded. The pile response such as pile deflection, bending moment and lateral soil pressure were studied, and it is shown that the pile response is different from that caused by the excavations which are unstructted. In "standard" problem, the effect of different pile head constraints on the pile response was investigated, the effect of lateral displacement of the wall, distance from the excavation face, pile stiffness, pile length and axial load on the pile response are also investigated when the pile head is constrained from deflection. The research finding was compared with other published case history and reasonably good agreement was found between them.

Effects of Initial Geometric Imperfections on Parametric Instability of Rectangular Plates

2001 ◽  
Author(s):  
Lyne St-Georges ◽  
G. L. Ostiguy
Keyword(s):  
Lateral Displacement ◽  
Plate Thickness ◽  
Parametric Instability ◽  
Experimental Tests ◽  
Rectangular Plates ◽  
Rational Analysis ◽  
Geometric Imperfections ◽  
Simply Supported ◽  
Geometrical Imperfections ◽  
Initial Geometric Imperfections

Abstract The authors present a rational analysis of the effect of initial geometric imperfections on the dynamic behaviour of rectangular plates activated by a parametric excitation. This subject has been extensively investigated theoretically in the past, but no experimental data seems to be complete enough to validate the theory. The main objective of this investigation is to fill this void by performing experimental tests on geometrically imperfect plates, and to highlight the geometric imperfection’s influence on resonance’s curves. The study is carried out for an isotropic, elastic, homogeneous, and thin rectangular plate. The plate under investigation is subjected to the action of an in-plane force uniformly distributed along two opposite edges, is initially stress free and simply supported. Theoretical calculation and experimental tests are performed. In the theoretical approach, a dynamic version of the Von Kármán non-linear theory is used to evaluate the lateral displacement of the plate. The test rig used in the experimentation simulates simply supported edges and can accept plates with different aspect ratio. The test plates are pre-formed with lateral deflection or geometrical imperfections, in a shape corresponding to various vibration modes. Comparison between experimental and theoretical results reveals good agreement and allows the determination of the theory’s limitations. The theory used correctly describes the behaviour of the plate when imperfection amplitude is inferior to the plate thickness.

Free vibration analysis of symmetrically laminated composite circular plates with curvilinear fibers

2017 ◽  
Vol 24 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Ahmed Guenanou ◽  
Abderrahim Houmat
Keyword(s):  
Free Vibration ◽  
Fiber Orientation ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Free Vibration Analysis ◽  
Published Data ◽  
Circular Plates ◽  
Simply Supported ◽  
Curvilinear Fibers

AbstractThe free vibration analysis of symmetrically laminated composite circular plates with curvilinear fibers is performed using the first-order shear deformation theory along with a curved hierarchical square finite element. The blending function method is used to describe accurately the geometry of the circular plate. The hierarchical shape functions are constructed from Legendre orthogonal polynomials. The element stiffness and mass matrices are integrated numerically by means of the Gauss-Legendre quadrature. The equations of motion are derived using Lagrange’s method. Results for the fundamental frequency are obtained for clamped and soft simply supported laminated composite circular plates with E-glass, graphite, and boron curvilinear fibers in epoxy matrices. The element is validated by means of the convergence test and comparison with published data for isotropic and laminated composite circular plates with rectilinear fibers. Contour plots of frequency as a function of fiber orientation angles for laminated composite circular plates with curvilinear fibers are presented. The fiber material and boundary conditions are shown to influence the distribution of frequency throughout the design space. Frequency curves as a function of fiber orientation angles for the first five modes of laminated composite circular plates with curvilinear fibers are also presented. They reveal that none of the first five modes of clamped and soft simply supported laminates is affected by crossing but modes 3 and 4 of clamped graphite/epoxy and boron/epoxy laminates are affected by veering.

scholarly journals A Finite Difference Solution of a Simply Supported Beam of Orthotropic Composite Materials Using Displacement Potential Formulation

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
S. K. Deb Nath
Keyword(s):  
Composite Materials ◽  
Finite Difference ◽  
Elastic Field ◽  
Elastic Behavior ◽  
Plane Stress Condition ◽  
Simply Supported Beam ◽  
Orthotropic Composite ◽  
Displacement Potential ◽  
Simply Supported ◽  
Potential Formulation

Here an efficient displacement potential formulation based finite difference technique is used to solve the elastic field of a simply supported beam of orthotropic composite materials. A simply supported beam made of orthotropic composite material under uniformly distributed loading is considered and its elastic behaviors under such loading conditions are analyzed considering plane stress condition. The solutions of the problem satisfy the force equilibrium conditions as well as boundary conditions. For understanding the elastic behavior of a simply supported beam, the displacement and stress components of some important sections of the beam are shown graphically. Effects of different orthotropic composite materials on the solutions are also analyzed. Besides, at a particular section of the beam, the comparative analysis of the elastic field is carried out by using the FDM and FEM methods.

On the Effects of Multiple Railway Track Alignment Defects on the CWR Thermal Buckling

2018 ◽  
Author(s):  
Giovanni Pio Pucillo
Keyword(s):  
Stress Field ◽  
Lateral Displacement ◽  
Thermal Buckling ◽  
Railway Track ◽  
Elastic Behavior ◽  
Internal Stresses ◽  
Hysteresis Cycle ◽  
Initial Alignment ◽  
The Real ◽  
Continuous Welded Rail

The lateral stability of the continuous welded rail (CWR) depends on a number of parameters which contribute to the progressive loss of the initial alignment of the track and its consequent predisposition to deform sideways, gradually or sharply, with serious risks for the safety both of passengers and operators. Different types of initial lateral defect, in terms of shape and size, are introduced by many authors in their own numerical and analytical model, but essentially all of them can be traced back — except for small “personalizations” — to the model proposed by Andrew Kish, who hypothesized the existence of a misalignment defect having the shape of a sine curve extended for half-wavelength, characterized by amplitude and wavelength values typical of the USA railroads. Moreover, all previous studies focused their attention on the introduction, in a geometrically perfect railway track, of a single defect confined in a zone of finite dimensions and having a rather simple geometry which qualitatively approximates the real defect, with the aim of simplifying the calculation of the buckling temperatures of the track associated with such geometry. In this paper, it was preliminarily analyzed the way the defect introduced in the track affects the critical temperature values. It started with a defect created artificially, applying to a geometrically perfect track and in the absence of thermal loads, a lateral displacement in the central transversal section of the track, and calculating, with the hypothesis of linear elastic behavior, the resulting deformed shape, which was assumed, after zeroing the corresponding stress field, as the input geometry for the subsequent buckling calculation. The deformed shape so obtained, being a Zimmermann deformed shape type, has no geometrical discontinuities near the defect and interprets in a natural way the defected geometry of the track, due to the dependence of its configuration on the flexural stiffness of the entire track in the lateral plane. Afterwards, modeling was carried out taking into account the real behavior of the track after the loss of its rectilinear configuration: the defect was created simulating the response of the track to a momentary lateral load — resulting, e.g., from train passages — which succeeded to cause a permanent displacement resulting from the elastic-plastic response of the track. The deformed shape of the track obtained in this way was used as the input geometry for the calculation of the buckling temperatures, once without resetting the stress field induced in the structure by the loading–unloading hysteresis cycle, and then considering the track free from internal stresses. The results show that both the numerical model that contemplate the defect introduced “plastically”, and that where the track is free from internal stresses, lead to more conservative results against the risk of thermal buckling in railway tracks made with CWR. A better approximation of the realistic representation of a generic defected railway track was pursued considering an indefinite number of defects distributed along the track, where each defect was characterized by different amplitude and wavelength values. The obtained results show that the presence of multiple defects further reduces the safety factor against the thermal track buckling phenomenon. The paper ends with the proposal of an evaluation criterion that takes into account the effects of multiple alignment defects on the critical buckling temperatures in continuous welded rail tracks.

Buckling of Drill Pipe in an Inclined Hole

1964 ◽  
Vol 86 (2) ◽  
pp. 214-218 ◽  
Author(s):  
D. B. Bogy ◽  
P. R. Paslay
Keyword(s):  
Stability Analysis ◽  
Gravity Field ◽  
Lateral Displacement ◽  
Drill Pipe ◽  
Vertical Plane ◽  
Approximate Analysis ◽  
Simple Experiment ◽  
Inclined Plane ◽  
Stability Equation ◽  
Simply Supported

The buckling of drill pipe in the vertical plane for the case of an inclined hole is studied. This is accomplished by performing a stability analysis of a simply supported column lying in compression on a rigid inclined plane in the presence of a gravity field. The lateral displacement of the column is restricted to be perpendicular to the plane. According to the results of an approximate analysis it is found that the system becomes unstable under the above conditions only if the lateral variational displacements are finite. The derived stability equation is verified for a particular case by a simple experiment. The results of this analysis can be used to determine the “crookedness” of a hole which, under specified conditions, will induce instability.

The Nonlinear Behaviour of Thin, Orthotropic, Curved Panels under Lateral Loading

1977 ◽  
Vol 19 (1) ◽  
pp. 30-37 ◽  
Author(s):  
I. H. Marshall ◽  
J. Rhodes ◽  
W. M. Banks
Keyword(s):  
Theoretical Analysis ◽  
Experimental Studies ◽  
Central Point ◽  
Lateral Loading ◽  
Nonlinear Behaviour ◽  
Uniform Pressure ◽  
Pressure Loading ◽  
Simply Supported ◽  
Aspect Ratios ◽  
Curved Panels

A theoretical analysis is presented for the snap-buckling behaviour of thin, orthotropic, spherically curved panels subject to central point and uniform pressure loading on the convex face. Clamped and simply supported edges are considered. The results are presented graphically for a range of panel aspect ratios and comparison is made with experimental studies.

Non-Circular Cylindrical Shells of Mid-Plane Asymmetric Construction Subjected to an Internal Pressure

1999 ◽  
Author(s):  
Zhaohui Chen ◽  
Jack R. Vinson
Keyword(s):  
Internal Pressure ◽  
Cross Section ◽  
Circular Cylindrical Shell ◽  
Lateral Displacement ◽  
The United States ◽  
Elastic Behavior ◽  
Material System ◽  
Lateral Deflection ◽  
Sandwich Construction ◽  
Bending Stresses

Abstract In future large cargo transport aircraft, such as the Global Range Transport proposed in the New World Vistas program of the United States Air Force, it is likely that the fuselage cross-section will be non-circular. For efficient cargo space, the fuselage cross-section being investigated is that of a rectangle with rounded corners. In order to minimize the resulting bending stresses, sandwich construction is being investigated, and in particular a mid-plane asymmetric construction is being studied to utilize bending-stretching coupling to minimize these bending stresses still further in the sandwich construction. The bending-stretching coupling can be introduced by using sandwich faces of different thickness and/or different materials and/or different fiber orientation of the composite material. The Theorem of Minimum Potential Energy is employed to investigate the subject problem. In this study, the lateral deflection that is assumed, a separable solution, employs the results of previous investigations: for the axial function, the lateral deflection of the analytical solution for a circular cylindrical shell with various boundary conditions subjected to an internal pressure is used; for the circumferential component of the lateral displacement, the series solution used previously by the authors for a ring solution of the same circumferential shape and loading is used. The magnitude and location of the maximum stresses in each face for each material system is then determined, and the maximum deflection is also found. Thus, the mechanics of the elastic behavior of this elastic thin walled shell subjected to this loading is adequately described. Some example problems are discussed, and various material systems and geometries are compared.

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