Effects Of Initial Tension Research Articles

A spatial stability theory of thin-walled steel beams pre-stressed by spatially inclined un-bonded cables and its FE formulation

A spatial stability theory of mono-symmetric thin-walled steel beams pre-stressed (PS) by spatially inclined cables is firstly derived using an energy method where it is assumed that deviators are rigid. Its FE formulation is then presented under bonded/un-bonded multi-deviator conditions. After that, validity and accuracy of the present formulation is demonstrated through numerical examples. Finally, effects of initial tension, deviator numbers, inclined cable profiles, and un-bonded/bonded conditions on lateral-torsional buckling (LTB) of the PS bi-/mono-symmetric beams are investigated under external loadings. Particularly, new findings on LTB characteristics of the PS beams are presented with a specific emphasis on the effects of increasing initial tension.

Characterization of Hardening Duffing Oscillator based on a Tensioned Wire System

In this paper, the characterization of mechanical system that behaves as a hardening Duffing oscillator is presented. This mechanical system comprises a mass attached to a tensioned wire which exhibits a hardening stiffness behavior when the displacement of the mass is large. Firstly, the equation of motion of the system is derived to provide the relationship between the applied static force and the resulting displacement. Then, the effect of initial tension, and number of the wires on the force-displacement relationship are analyzed. It has been found that a higher tension will produce higher linear stiffness, whilst having a negligible effect on cubic stiffness. Moreover, the nonlinearity is less sensitive for small inequality between the length of wire on the left and right side of the mass. The results presented herein provide an insight of the system behavior for its application as a vibration isolator.

Effect of initial tension on mechanics of adhered graphene blisters

The effect of initial tension on mechanics of adhered graphene blisters is investigated by extending Hencky’s solution to cases with an initial tension. The system parameters including maximum blister deflection, pressure difference across the membrane, and critical delamination pressure under various initial tensions are modeled and calculated. The dependences of critical pressure on the radius and depth of etched microcavity are also demonstrated and compared with the previous work which does not consider the initial tension. The results show that the added adhesion energy between monolayer graphene membrane and SiO2 substrate can reach 0.0954 J/m2 with a reported maximum initial tension of 2.4 N/m taken into account, which accounts for 21.2 % of the measured average value 0.45 J/m2. Thus, the initial tension should be considered in further adhesion energy measurements of graphene/substrate interfaces.

Linear Analytical Study of Large Deflection of Piezoelectric Layered Plate Under Initial Tension

AbstractThe linear problem of large deflection of a clamped and layered piezoelectric circular plate under initial tension due to lateral pressure is solved. Von Karman plate theory for large deflection is extended to a symmetrically laminated case including a piezoelectric layer. The thus derived nonlinear governing equations are simplified by neglecting the arising nonlinear terms, yielding a modified Bessel equation or a standard Bessel equation for the lateral slope. These equations are solved analytically by imposing boundary conditions for the clamped edge. For a 3-layered nearly monolithic plate with a low applied voltage upon the piezoelectric layer, the results are in a good agreement with those available in literature for a single-layered plate under pure mechanical loading, thus validates the present approach. Typical 3-layered piezoelectric plates are then implemented and the results show that, piezoelectric effect seems to be apparent only up to a moderate initial tension. For a relatively high pretension, the effect of initial tension appears to be dominant, yielding nearly the same results for the structural responses, regardless of the piezoelectric effect, i.e., the magnitude of voltage applied upon the piezo-electric layer.

Flexural transient response of elastically supported elliptical plates under in-plane loads using Mathieu functions

The elaborated method of eigenfunction expansion in elliptic coordinates is employed to obtain an exact time-domain series solution, involving products of angular and radial Mathieu functions, for the forced flexural vibrations of a thin elastic plate of elliptical planform. The plate is supported by a constant moduli two-parameter foundation, while elastically restrained against translation and rotation at its edge, and subjected to the combined action of uniform in-plane static edge forces and general arbitrary time-dependent transverse loads with arbitrary initial conditions. Numerical calculations are carried out for the displacement response of clamped or simply supported elliptical plates of selected aspect ratios in various practical loading configurations (i.e., an impulsive point load, a point force in circular motion, a uniformly distributed harmonic load, and a blast load), with or without an elastic foundation, while taking the effects of initial tension or compression below the buckling load into consideration. Limiting cases are considered and good agreements with available results as well as with the computations made by using a commercial finite element package are obtained.

Nonlinear study of large deflection of simply supported piezoelectric layered-plate under initial tension

The nonlinear problem of large deflection of a simply supported piezoelectric layered plate under initial tension is studied. The approach follows von Karman’s plate theory for large deflection for a symmetrically layered isotropic case including a piezoelectric layer. The nonlinear governing equations are solved using a finite difference method, by taking the associated linear analytical solution as an initial guess in the numerical iteration procedure. The results for a nearly monolithic plate under a very low applied voltage are found to correlate well with available solutions for a single-layered case under pure mechanical loading and thus the present approach is validated. For three-layered plates made of typical silicon based materials, various initial tension and lateral pressure are considered, and different applied voltages up to a moderate magnitude are implemented. No edge effect was observed, in contrast to the cases of clamped plates in literature. In additions, varying the layer moduli seems to have an insignificant effect upon the structural responses of the layered plate. On the other hand, the piezoelectric effect tends to be apparent only in a low pretension condition. For a relatively large pretension, the effect of initial tension becomes dominant, yielding nearly unique solutions for the structural responses, regardless of the magnitudes of the applied voltage and the lateral pressure.

750 アクチンフィラメントの初期張力が細胞の全体的な引張特性に及ぼす影響 : 細胞力学シミュレーションによる考察(OS21.細胞・生体分子の計算バイオメカニクス(3),オーガナイズドセッション)

750 アクチンフィラメントの初期張力が細胞の全体的な引張特性に及ぼす影響 : 細胞力学シミュレーションによる考察(OS21.細胞・生体分子の計算バイオメカニクス(3),オーガナイズドセッション)

An In Vivo Biomechanical Study on the Tension–Versus–Knee Flexion Angle Curves of 2 Grafts in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction: Effects of Initial Tension and Internal Tibial Rotation

The purposes of this study were to determine the relation between the graft tension and the knee flexion angle in the anteromedial (AM) and posterolateral (PL) bundles of a clinically simulated anatomic double-bundle anterior cruciate ligament (ACL) reconstruction procedure and to clarify the effect of initial tension on the tension-versus-flexion curve of each graft, as well as the effect of internal rotation of the tibia on the tension of the 2 grafts. During ACL reconstruction in 30 patients, 2 suture anchors with a No. 1 polyester suture were firmly screwed into the center of the anatomic attachment of the AM and PL bundles on the femur, respectively, and each graft tension was measured with a strain gauge-type tensiometer attached at the end of the suture under 2 conditions of initial tension. The averaged tension-versus-flexion curves were significantly different between the AM and PL grafts under each initial tension condition (P < .0001). The initial tension applied at 30 degrees of knee flexion significantly affected the absolute values of each graft tension at each knee flexion angle (P < .0001) but did not significantly affect the tension-versus-flexion curve pattern of each graft. The maximal internal rotation of the tibia significantly increased the tension on both the AM and PL grafts at knee flexion angles of less than 60 degrees under each initial tension condition (P < .0001). The tension-versus-flexion curves of the 2 sutures, which mimicked the AM and PL grafts reconstructed clinically with the anatomic double-bundle ACL reconstruction procedure, were significantly different in the tension values. Differences in initial tension applied to the 2 grafts significantly affected the absolute values of each graft tension at each knee flexion angle but did not significantly affect the tension-versus-flexion curve pattern. The maximal internal rotation of the tibia significantly increased the tension on both the AM and PL suture grafts at knee flexion angles of less than 60 degrees . Level I, testing of previously developed diagnostic criteria in series of consecutive patients with universally applied gold standard.

テニスボールとストリングス(弦)の衝突解析(テニス(1))

Phenomena of tennis ball impact on a string are formulated through the application of Duhamel's integral. The equations formulated are solved numerically. The effects of initial tension and Young's modulus of the string are investigated.

Vibrations of belts and belt drives

During its operation, a power transmission belt can undergo axial, transverse and torsional motion. Models available for analyzing the free and forced vibrations of the belt are discussed. The effects of initial tension, transport velocity, bending rigidity, support flexibility, large displacements and belt and pulley imperfections are discussed. Vibrations of belt drives are also considered, and the influence of several complicating factors are mentioned. This article reviews the state-of-the-art in vibration analysis of power transmission belts. Many contributions found in the literature are brought together, and some new results are also included.

A Study on Transmission Characteristics of Toothed Belt Drives : 1st report, Effect of Initial Tension on Tight side and Slack Side Tensions

In this report, the meshing states of belt and pulley teeth at the initial tension and in the process when the transmission force occurs from the condition of the initial tension are theoretically discussed. From this study the following conclusions have been obtained, (1) the direction of belt slip at the time of starting varies with initial belt tension, and the meshing state of belt and pulley teeth converges to a certain condition, (2) the stiffness of the belt system and the coefficient of change of tension are affected by the meshing state of belt and pulley, and (3) the relation between tight and slack side tensions and the relation between the angle of rotation of the pulley and the belt tension are analyzed, the calculated results agreeing approximetely with the experimental values.