Uniform Axial Tension Research Articles

Mixed Finite Element for Crack Analysis in Functionally Graded Material

This study presents a mixed finite element formulated using isoparametric techniques and extended to analyze quasi-static crack propagation in functionally graded materials. The mixed mode is analyzed for homogeneous and functionally graded beamssubjected to three-point bending and for homogeneous and functionally graded plates under uniform axial tension. The mixed finite element results are compared with previous experimental and numerical results published in the literature.

Free vibration analysis of axially moving laminated beams with axial tension based on 1D refined theories using Carrera unified formulation

In this paper, free vibration finite element analysis of axially moving laminated composite beams subjected to axial tension is studied. It is assumed that the beam has a constant axial velocity and is subject to uniform axial tension. The analysis is based on higher-order theories that have been presented by Carrera Unified Formulation (CUF). In the CUF technique, the three dimensional (3D) displacement fields are expressed as the approximation of the arbitrary order of the displacement unknowns over the cross-section. This higher-order expansion is considered in equivalent single layer (ESL) model. The governing equations of motion are obtained via Hamilton\' s principle. Finally, several numerical examples are presented and the effect of the ply-angle, travelling speed and axial tension on the natural frequencies and beam stability are demonstrated.

化学镀Ni-P光纤布拉格光栅的均匀轴向拉力响应

To research the uniform axial tension effect of an Electroless plating Ni-P coated Fiber Bragg Grating(ENFBG),the stress and strain properties of the ENFBG were analyzed based on its axial symmetry.The finite element method was used for theoretical calculations,then it was verified by following experiments.Theoretical calculation shows that under uniform axial tension,the core of the ENFBG is drawn uniformly,the shearing strain is far less than normal strain and can be omitted.The normal strain is proportional to the axial tension,and the change of center wavelength of ENFBG is proportional to that of the tension too.However,because of the difference of mechanic parameters between electroless plating Ni-P coating and optical fiber,the metal coating reduces the uniform axial tension sensitivity of the FBG.In sensor experiment,when the thickness of the coating is 7.25 μm,the sensitivity is 12.45 pm/MPa,R-square is 0.999 6,and the theoretical calculation value is 12.744 pm/MPa.Moreover,the sensitivity is decreased with the increase of the thickness of metal coating.The ENFBG is an excellent uniform axial tension sensor,because its center wavelength shows high linearity to uniform axial tension and its metal coating can provide good protection.

Axisymmetric finite cylinder with one end clamped and the other under uniform tension containing a penny-shaped crack

This study considers the axisymmetric analysis of a finite cylinder containing a penny-shaped transverse crack. Material of the cylinder is assumed to be linearly elastic and isotropic. One end of the cylinder is bonded to a fixed support while the other end is subjected to uniform axial tension. Solution is obtained by superposing the solutions for an infinite cylinder loaded at infinity and an infinite cylinder containing four cracks and a rigid inclusion loaded along the cracks and the inclusion. When the radius of the inclusion approaches the radius of the cylinder, its mid-plane becomes fixed and when the radius of the distant cracks approach the radius of the cylinder, the ends become cut and subject to uniform tensile loads. General expressions for the perturbation problem are obtained by solving Navier equations with Fourier and Hankel transforms. Formulation of the problem is reduced to a system of five singular integral equations. By using Gauss–Lobatto and Gauss–Jacobi integration formulas, these five singular integral equations are converted to a system of linear algebraic equations which is solved numerically. Stress distributions along the rigid support, stress intensity factors at the edges of the rigid support and the crack are calculated.

Corrected Formulas for Natural Frequencies of Cantilever Beams Under Uniform Axial Tension

N ATURAL frequencies of beams under axial tensile force are of interest in many applications such as rotating fan blades, turbine blades, etc. There have been extensive studies on beam dynamics considering the effects of rotation. Rosales and Filipich [1], for example, studied the dynamic stability of a spinning beam with an axial dead load.Naguleswaran [2] presented a study of lateral vibration of a centrifugally tensioned uniform Euler–Bernoulli beam. He developed the database of nondimensional parameters of speed and natural frequencies for various offset ratios of a beam. Lee [3] studied the dynamic response of a rotating Timoshenko beam subjected to axial forces and a moving load. Closed-form solutions for the natural frequencies of rotating pinned–pinned beams are available (for example, Timoshenko et al. [4]).However, other boundary conditions are not readily amenable to such a treatment. Gorman [5] presented the variation of the frequency parameter with axial tension parameter for the six modes of clamped–pinned and clamped–clamped beams. Bokaian [6] presented a comprehensive study of the effect of a constant axial tensile force on the natural frequencies andmode shapes of a uniform single-span beam, with different combinations of the end conditions. Although simple relations could capture the behavior of beams with various boundary conditions, clamped–free beams showed deviant behavior. Thus, the present study focuses on the natural frequencies of a clamped–free beam under uniform axial tension. The relations available for finding the fundamental frequency of a cantilever beam under uniform axial tension are summarized next: The Bokaian [6] characteristic equation is

축방향으로 이동하는 티모센코보의 동특성에 관한 스펙트럴요소 해석

The use of frequency-dependent spectral element matrix (or exact dynamic stiffness matrix) in structural dynamics is known to provide very accurate solutions, while reducing the number of degrees-of-freedom to resolve the computational and cost problems. Thus, in the present paper, the spectral element model is formufor the axially moving Timoshenko beam under a uniform axial tension. The high accuracy of the pre-spectral element is then verified by comparing its solutions with the conventional finite element solutions and exact analytical solutions. The effects of the moving speed and axial tension on the vibration characteris-tics, the dispersion relation, and the stability of a moving Timoshenko beam are investigated, analytically and numerically.<br/>

Spectral analysis for the transverse vibration of an axially moving Timoshenko beam

The use of frequency-dependent spectral element matrix (or exact dynamic stiffness matrix) in structural dynamics is known to provide very accurate solutions, while reducing the number of degrees of freedom to resolve the computational and cost problems. Thus, in the present paper, the spectral element model is formulated for the axially moving Timoshenko beam under a uniform axial tension. The high accuracy of the present spectral element is then verified by comparing its solutions with the conventional finite element solutions and exact analytical solutions. The effects of the axial velocity and axial tension on the vibration characteristics, the dispersion relation, and the stability of a moving Timoshenko beam are analytically and numerically investigated.

Thermal stability of intrinsic stress birefringence in optical fibers

Through Duhamel's analogy in thermoelasticity, the condition of zero temperature fluctuation of intrinsic stress birefringence is derived. The condition requires the regions bordering the nonaxisymmetric interfaces in the fiber cross-section to have identical thermoelastic properties but different fictive temperatures. It is found that thermal instability of birefringence is predominantly caused by the mismatch in expansion coefficients between these regions. The condition may be incorporated into most fibers during performance preparation, whether silica based or not. Birefringent fibers satisfying this condition will also have intrinsic stress birefringence stabilized against hydrostatic-pressure perturbation on the surface as well as uniform axial tension at the ends, regardless of coating properties.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Non-linear beam-type vibrations of long cylindrical shells

This paper presents a closed-form solution of the problem of free beam-type vibration of a long cylindrical shell subject to uniform axial tension, uniform internal pressure, and elastic axial restraint. The shell is assumed to be clamped at the ends. The bending moment-curvature relationship employed in this paper is non-linear due to the effect of ovalization (flattening) of initially circular cross sections. Another non-linear effect taken into account is the stretching of the shell axis which is caused by the axial restraint. The analysis results in a cubic differential equation; the frequency of the solution of this equation is found exactly using elliptic integrals.

Strain-based finite elements for the analysis of cylinders with holes and normally intersecting cylinders

A finite element solution to the problems of stress distribution for cylindrical shells with circular and elliptical holes and also for normally intersecting thin elastic cylindrical shells is given in the present paper. Quadrilateral and triangular curved finite elements are used in the analysis. The elements are of a new class, based on simple independent generalised strain functions insofar as this is allowed by the compatibility equations. The elements also satisfy exactly the requirements of strain-free-rigid body displacements and uses only the external “geometrical” nodal degrees of freedom to avoid the difficulties associated with unnecessary internal degrees of freedom. A rectangular curved element was first developed and applied to the analysis of the familiar pinched cylinder and barrel vault problems (Ashwell and Sabir [1]). The results converge rapidly for displacements as well as for stresses. Further tests were carried out to investigate the ability of this element in predicting the high stresses in the neighbourhood of applied concentrated loads, (Sabir and Ashwell [2]). The loads considered were either radial or axial forces as well as moments about tangents to the circular cross section. The results obtained were not only in agreement with those of Forsberg and Flügge [3] but when plotted for the complex parameters defining proportions of the shell and flexibility as suggested by Calladine [4], their general forms corresponded closely with theoretical predictions. In the present paper we first develop strain based quadrilateral and triangular elements and apply them to the solution of the problem of stress concentrations in the neighbourhood of small and large circular and elliptical holes when the cylinders are subjected to a uniform axial tension. These results are compared with analytical solutions based on shallow shell approximations and show that the use of these strain based elements obviates the need for using an inordinately large number of elements. Normally intersecting cylinders are common configurations in structural components for nuclear reactor systems and design information for such configurations are generally lacking. The opportunity is taken in the present paper to provide a finite element solution to this problem. A method of substructing will be introduced to enable a solution to the large number of non banded set of simultaneous equations encountered. The solutions show good agreement when compared with experimental results of Corum, Bolt, Greenstreet and Gwaltney [5].

Stresses around a circular hole in a shallow conical shell

Analytical solutions are presented for the stresses in a shallow conical shell having a circular hole on its lateral surface. The shell which is closed at both ends, is subjected to a uniform axial tension and internal pressure balanced only by distributed transverse shear forces at the boundary of the hole. The method of analysis involves perturbations in parameters defining curvature and the cone angle of the shell (β and ϵ respectively). For small values of these parameters, significant membrane and bending stresses are obtained retaining terms of order of β2 and ϵ2.

Stress Concentration Around a Heterogeneous Insertion of Ellipsoid in an Infinite Elastic Body I.

Problems of stress concentration in three dimensions weve treated by H. Neuber in his Kerbspannungslehre. The late Prof. K. Sezawa and also Prof. G. Nishimura studied the stress concentration around a heterogeneous insertion of sphere in an infinite elastic body when it is under uniform tension, simple shear, etc. In this paper. I studied the stress concentration around a heterogeneous insertion of ellipsoid in an infinite elastic body when it is under uniform axial tension and plane hydrostatic state of pressure in the plane perpendicular to the axis of revolution.