Axial Bars Research Articles

Analysis of a Steel-Concrete Composite Plate resting on Axial Bars using the Finite Element Method

This study applied finite element analysis to a steel-concrete composite plate resting on the axial bar, using a four-node quadrilateral finite element for a steel-concrete composite plate combined with a truss element. Plate displacements and deformations were used to formulate the finite element method based on the first-order plate theory, also known as the Mindlin plate theory. The finite element analysis to combine steel-concrete composite plates and axial bars was implemented in MATLAB. Numerical examples were used in detail, showing a very small difference between the current study and the SAP2000 results.

Free longitudinal vibrations of functionally graded tapered axial bars by pseudospectral method

In this work, the problem of free longitudinal vibration of rods with variable cross-sectional area and material properties is investigated using the pseudospectral method. With the gradation of material properties like modulus of elasticity and mass density in the axial direction, the results corresponding to a functionally graded axial bar are obtained using the proposed pseudospectral formulation. The pseudospectral formulation used is relatively easy to implement and powerful in analyzing vibration problems. With the help of several numerical examples, the non-dimensional natural frequencies of rods obtained using the pseudospectral method are compared with those obtained by the analytical solution, generalized finite element method, the discrete singular convolution method and differential transformation method. The numerical results obtained show that the proposed technique allows boundary conditions to be incorporated easily and yields results with good accuracy and faster convergence rates than other methods.

An approximate spectral element model for the dynamic analysis of an FGM bar in axial vibration

As FGM (functionally graded material) bars which vibrate in axial or longitudinal direction have great potential for applications in diverse engineering fields, developing a reliable mathematical model that provides very reliable vibration and wave characteristics of a FGM axial bar, especially at high frequencies, has been an important research issue during last decades. Thus, as an extension of the previous works (Hong et al. 2014, Hong and Lee 2015) on three-layered FGM axial bars (hereafter called FGM bars), an enhanced spectral element model is proposed for a FGM bar model in which axial and radial displacements in the radial direction are treated more realistic by representing the inner FGM layer by multiple sub-layers. The accuracy and performance of the proposed enhanced spectral element model is evaluated by comparison with the solutions obtained by using the commercial finite element package ANSYS. The proposed enhanced spectral element model is also evaluated by comparison with the author

Dynamics of a functionally graded material axial bar: Spectral element modeling and analysis

Functionally graded material (FGM) bars in axial motion (hereafter called “FGM axial bars”) have great potential for applications in many engineering fields. Therefore, it is important to develop a reliable mathematical model that can provide very accurate dynamic and wave propagation characteristics in FGM axial bars, especially at high frequencies. As an extension of our previous work, we present a spectral element model for a modified FGM axial bar model wherein nonuniform lateral contraction in the thickness direction is taken into account. We assume that material properties of the modified FGM axial bar model vary in the radial direction according to the power law. The performance of the proposed spectral element model is validated through comparison with solutions from a conventional finite element model, and with the results from the previous FGM axial bar model. In addition, the effects of lateral contraction on the dynamic and wave propagation characteristics in example FGM axial bars are numerically investigated.

Dynamics and waves characteristics of the FGM axial bars by using spectral element method

The functionally graded material bars in axial or longitudinal motions (simply FGM axial bars) have a great potential for the applications in many engineering fields. Thus it is essential to develop a reliable computational model which has the capability to accurately predict the dynamics and waves in the FGM axial bars, especially at the high frequency regime. Thus this paper presents a spectral element model for the FGM axial bars whose material properties vary in the radial direction according to the power law. The spectral element model is formulated from the governing equations of motion in the frequency domain by using the variational method. The radial contraction is taken into account in the spectral element model by adopting the Mindlin–Herrmann rod theory. The accuracy of the present spectral element model is verified first in due course by comparing with the solutions obtained by the conventional finite element model. The dynamics and wave characteristics of the FGM axial bars are then numerically investigated.

Deflection of Structures using Principle of Quasi Work

A new methodology for obtaining deflections of structures is presented in this paper. It is based on Principle of Quasi Work, which connects two topologically similar systems thereby leading to a unique concept of standard elements for every category of structural problems. Using a priory known equation of deformation/deflection of elastic axis of these elements, solution for equation of deformed/ deflected elastic line of other structural members of similar category having different loading and boundary conditions is presented here. Th is methodology is easy to use as deflection of a given structure is obtained mostly by simple mu ltiplications and it also eliminates the use of internal force/bending mo ment expressions unlike conventional methods. Even though this methodology can be applied to any structure, its use is illustrated for one dimensional structural elements (viz. axial bars, torsion rods and beams) for the sake of conciseness and clarity. The concept of topologically similar system is exp lored for each category of elements as it lies at the heart of the principle of quasi work.

フーチングからの軸方向主鉄筋の抜け出し量評価法に関する研究

フーチングからの軸方向主鉄筋の抜け出し量評価法に関する研究

EXPERIMENTAL STUDY ON INFLUENCE OF TENSION FORCE ON DOWEL EFFECT OF AXIAL BARS

The object of this paper is to investigate experimentally the influence of tension force and cover on the dowel effect of axial bars. Failure mode, dowel force-displacement relationship, dowel capacity and deformation of bars were investigated in detail under dowel load and tension force simultaneously. As a result, we found that dowel capacity increases as the thickness of cover increases, but its capacity decreases exponentially with increasing tension force. Furthermore, it is pointed out that the dowel effect of axial bar depends on the characteristics of concrete rather than those of bar. Finally, the posibilities of introducing the dowel effect into shear strength of RC members in design were discussed.

A SEGMENTAL METHOD FOR THE DISCRETE OPTIMUM DESIGN OF STRUCTURES

A simple method based upon linear programming is described for the design of minimum weight structures under the restrictions that member sizes and/or material properties may be chosen only from discrete sets. The types of structures considered are those composed of axial force bars, membrane plates and shear panels. The method avoids the combinatorial nature of discrete optimization by introducing the concept of segmental members. The segmental optimum design is found by linear programming. Its weight is a lower bound to the weight of the discrete optimum design. A simple method for achieving a discrete optimum design from a segmental optimum design is described. Several examples of discrete optimum truss designs are presented.