A New Method for Calculating Bending Moment and Shear Force in Moving Load Problems

2000 ◽  
Vol 68 (2) ◽  
pp. 252-259 ◽  
Author(s):  
A. V. Pesterev ◽  
C. A. Tan ◽  
L. A. Bergman
Keyword(s):  
Series Expansion ◽  
Shear Force ◽  
Moving Load ◽  
A Priori ◽  
Series Representation ◽  
Bending Moment ◽  
Continuous System ◽  
Distributed Parameter ◽  
Moving Loads ◽  
Moving Oscillator

In this paper, a new series expansion for calculating the bending moment and the shear force in a proportionally damped, one-dimensional distributed parameter system due to moving loads is suggested. The number of moving forces, which may be functions of time and spatial coordinate, and their velocities are arbitrary. The derivation of the series expansion is not limited to moving forces that are a priori known, making this method also applicable to problems in which the moving forces depend on the interactions between the continuous system and the subsystems it carries, e.g., the moving oscillator problem. A main advantage of the proposed method is in the accurate and efficient evaluation of the bending moment and shear force, and in particular, the shear jumps at the locations where the moving forces are applied. Numerical results are presented to demonstrate the rapid convergence of the new series representation.

Application of the Mode-Acceleration Technique to the Solution of the Moving Oscillator Problem

1999 ◽  
Author(s):  
Alexander V. Pesterev ◽  
Lawrence A. Bergman
Keyword(s):  
Shear Force ◽  
Series Representation ◽  
Bending Moment ◽  
Static Solution ◽  
Distributed Parameter ◽  
Distributed Parameter System ◽  
Parameter System ◽  
One Dimensional ◽  
Acceleration Technique ◽  
Moving Oscillator

Abstract The problem of calculating the dynamic response of a one-dimensional distributed parameter system excited by an oscillator traversing the system with an arbitrarily varying speed is investigated. An improved series representation for the solution is derived that takes into account the jump in the shear force at the point of the attachment of the oscillator, which makes it possible to efficiently calculate the distributed shear force and, where applicable, bending moment. The improvement is achieved through the introduction of the “quasi-static” solution, an approximation to the desired one, which makes it possible to apply to the moving oscillator problem the “mode-acceleration” technique conventionally used for acceleration of series in problems related to the steady-state vibration of distributed systems. Numerical results illustrating the efficiency of the method are presented.

An Improved Series Expansion of the Solution to the Moving Oscillator Problem

1999 ◽  
Vol 122 (1) ◽  
pp. 54-61 ◽  
Author(s):  
A. V. Pesterev ◽  
L. A. Bergman
Keyword(s):  
Shear Force ◽  
Series Representation ◽  
Bending Moment ◽  
Static Solution ◽  
Distributed Parameter ◽  
One Dimensional ◽  
Moving Force ◽  
Coupling Force ◽  
Force Problem ◽  
Moving Oscillator

The problem of calculating the dynamic response of a one-dimensional distributed parameter system excited by an oscillator traversing the system with an arbitrarily varying speed is investigated. An improved series representation for the solution is derived that takes into account the jump in the shear force at the point of the attachment of the oscillator, which makes it possible to efficiently calculate the distributed shear force and, where applicable, bending moment. The improvement is achieved through the introduction of the “quasi-static” solution, which is an approximation to the desired solution, and is also based on the explicit representation of the solution of the moving oscillator problem as the sum of the solution of the corresponding moving force problem and that of the problem of vibration of the distributed system subject to the elastic coupling force. Numerical results illustrating the efficiency of the method are presented. [S0739-3717(00)01001-1]

Methods for Calculating Bending Moment and Shear Force in the Moving Mass Problem

2004 ◽  
Vol 126 (4) ◽  
pp. 542-552 ◽  
Author(s):  
Bruno Biondi ◽  
Giuseppe Muscolino ◽  
Anna Sidoti
Keyword(s):  
Dynamic Analysis ◽  
Series Expansion ◽  
Shear Force ◽  
Bending Moment ◽  
Continuous System ◽  
Correction Method ◽  
System Response ◽  
Moving Mass ◽  
Dynamic Correction ◽  
Different Levels

Two methods able to capture with different levels of accuracy the discontinuities in the bending moment and shear force laws in the dynamic analysis of continuous structures subject to a moving system modeled as a series of unsprung masses are presented. The two methods are based on the dynamic-correction method, which improves the conventional series expansion by means of a pseudostatic term, and on an eigenfunction series expansion of the continuous system response, which takes into account the effect of the moving masses on the structure, respectively.

Sensitivity Analysis of Continuous Curved Bridge under Different Curvature Radius

2014 ◽  
Vol 587-589 ◽  
pp. 1650-1654
Author(s):  
Mu Xin Luo ◽  
Jing Hong Gao
Keyword(s):  
Moving Load ◽  
Bending Moment ◽  
Element Model ◽  
Internal Force ◽  
Curvature Radius ◽  
Moving Loads ◽  
Dead Load ◽  
Actual Structure ◽  
Curved Bridge ◽  
The Dead

In the condition of the same span, to change the continuous curved bridge's curvature radius and under the dead load and moving load to compare how the internal force changes in different curvature radius. The finite element model is established to simulate the actual structure by Midas Civil. Results in a continuous curved bridge which main span of less than 60m, under the dead load, bending moment (-y) is unlikely to change, reinforced by a straight bridge can meet the requirements; under the moving loads, the curvature radius of the bending moment (-y) has little influence, should focus on increase in torque and bending moment (-z).

Vibration of a Beam Excited by a Moving Flexible Body

2006 ◽  
Vol 5-6 ◽  
pp. 457-464
Author(s):  
Hua Jiang Ouyang ◽  
John E. Mottershead
Keyword(s):  
A Priori ◽  
Flexible Body ◽  
Static Deflection ◽  
Combined Approach ◽  
Moving Loads ◽  
Contact Interface ◽  
Moving Body ◽  
The Subject ◽  
Moving Oscillator ◽  
Very High

The vibration of a beam excited by a moving simple oscillator is an extensively studied problem. However, the vibration of a beam excited by an elastic body with conformal contact has attracted much less attention. This is the subject of the present paper. The established model is a big improvement to the moving oscillator model and has many engineering applications. Because the moving body is flexible, the moving loads at the contact interface are not known a priori and must be determined together with the dynamics of the whole system. Considerable mathematical complication arises as a result, compared with the moving-oscillator problem, even if the contact is assumed to be complete. In this paper, the equation of motion of the beam and the moving body are established separately using an analytical-numerical combined approach. The equation for the moving loads is established through the displacement continuity at the contact interface. It is found from the simulated numerical results that the deflection of the beam displays several cycles of oscillation during the passage of the moving body and can exceed the maximum static deflection at moderate speeds, but is close to the static deflection when the speed is either very low or very high.

Imperialist Competitive Algorithm for Multiobjective Optimization of Ellipsoidal Head of Pressure Vessel

2011 ◽  
Vol 110-116 ◽  
pp. 3422-3428 ◽  
Author(s):  
Behzad Abdi ◽  
Hamid Mozafari ◽  
Ayob Amran ◽  
Roya Kohandel
Keyword(s):  
Genetic Algorithm ◽  
Pressure Vessel ◽  
Shear Force ◽  
Minimum Weight ◽  
Bending Moment ◽  
Imperialist Competitive Algorithm ◽  
Optimum Shape ◽  
Working Pressure ◽  
Competitive Algorithm ◽  
Bending Stresses

This work devoted to an ellipsoidal head of pressure vessel under internal pressure load. The analysis is aimed at finding an optimum weight of ellipsoidal head of pressure vessel due to maximum working pressure that ensures its full charge with stresses by using imperialist competitive algorithm and genetic algorithm. In head of pressure vessel the region of its joint with the cylindrical shell is loaded with shear force and bending moments. The load causes high bending stresses in the region of the joint. Therefore, imperialist competitive algorithm was used here to find the optimum shape of a head with minimum weight and maximum working pressure which the shear force and the bending moment moved toward zero. Two different size ellipsoidal head examples are selected and studied. The imperialist competitive algorithm results are compared with the genetic algorithm results.

scholarly journals Dynamic Behavior of Tied-Arch Bridges under the Action of Moving Loads

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Paolo Lonetti ◽  
Arturo Pascuzzo ◽  
Alessandro Davanzo
Keyword(s):  
Dynamic Behavior ◽  
Structural Characteristics ◽  
Moving Load ◽  
Sensitivity Analyses ◽  
Impact Factors ◽  
Moving Loads ◽  
Centripetal Acceleration ◽  
Design Variables ◽  
Dynamic Amplification ◽  
Arch Bridges

The dynamic behavior of tied-arch bridges under the action of moving load is investigated. The main aim of the paper is to quantify, numerically, dynamic amplification factors of typical kinematic and stress design variables by means of a parametric study developed in terms of the structural characteristics of the bridge and moving loads. The basic formulation is developed by using a finite element approach, in which refined schematization is adopted to analyze the interaction between the bridge structure and moving loads. Moreover, in order to evaluate, numerically, the influence of coupling effects between bridge deformations and moving loads, the analysis focuses attention on usually neglected nonstandard terms in the inertial forces concerning both centripetal acceleration and Coriolis acceleration. Sensitivity analyses are proposed in terms of dynamic impact factors, in which the effects produced by the external mass of the moving system on the dynamic bridge behavior are evaluated.

The Influence of Rotatory Inertia and Transverse Shear on the Dynamic Plastic Behavior of Beams

1979 ◽  
Vol 46 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Norman Jones ◽  
J. Gomes de Oliveira
Keyword(s):  
Transverse Shear ◽  
Shear Force ◽  
Yield Criterion ◽  
Yield Condition ◽  
Bending Moment ◽  
Plastic Behavior ◽  
Plastic Response ◽  
Rotatory Inertia ◽  
Perfectly Plastic ◽  
Theoretical Procedure

The theoretical procedure presented herein examines the influence of retaining the transverse shear force in the yield criterion and rotatory inertia on the dynamic plastic response of beams. Exact theoretical rigid perfectly plastic solutions are presented for a long beam impacted by a mass and a simply supported beam loaded impulsively. It transpires that rotatory inertia might play a small, but not negligible, role on the response of these beams. The results in the various figures indicate that the greatest departure from an analysis which neglects rotatory inertia but retains the influence of the bending moment and transverse shear force in the yield condition is approximately 11 percent for the particular range of parameters considered.

Sign in / Sign up

Export Citation Format

Share Document