Dynamic Analysis of a Delaminated Composite Beam due to a Moving Oscillatory Mass

Author(s):  
Mohammad-Taghi Ahmadian ◽  
Mohammad-Hosein Kargarnovin ◽  
Ramazan-Ali Jafari-Talookolaei

This paper deals with the dynamic analysis of a delaminated composite beam under the action of moving oscillatory mass. The beam is analyzed as four interconnected sub-beams using the delamination limits as their boundaries. The constrained model is used to model the delamination region. The continuity and equilibrium conditions are satisfied between the adjoining beams. The beam response variation due to the delamination with respect to the intact beam has been investigated. Furthermore, the possible separation of the moving oscillator from the beam during the course of the motion is investigated by monitoring the contact force between the oscillator and the beam. The effect of the parameters such as the oscillator axial velocity and the size, depth and spanwise location of the delamination on the dynamic response of the beam and on the oscillator separation from the delaminated beam has been studied. It is shown that the delamination has significant influence on the dynamic response of the beam and on the oscillator separation from the beam.

2012 ◽  
Vol 19 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Mohammad H. Kargarnovin ◽  
Mohammad T. Ahmadian ◽  
Ramazan Ali Jafari-Talookolaeia

AbstractA composite beam with single delamination under the action of moving load has been modeled accounting for the Poisson’s effect, shear deformation, and rotary inertia. The existence of the delamination changes the stiffness of the structure, and this affects the dynamic response of the structure. We have used a constrained mode to simulate the behavior between the delaminated surfaces. Based on this mode, eigensolution technique is used to obtain the natural frequencies and their corresponding mode shapes for the delaminated beam. Then, the Ritz method is adopted to derive the dynamic response of the beam subjected to a moving load. The obtained results for the free and forced vibrations of beams are verified against reported similar results in the literature. Moreover, the maximum dynamic response of such beam is compared with an intact beam. The effects of different parameters such as the size, depth, and spanwise location of the delamination, the load velocity, the different ply configurations, and the Poisson’s effect on the dynamic response of the beam are studied.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Nguyen Thai Chung ◽  
Nguyen Thi Hong ◽  
Le Xuan Thuy

This paper presents the finite element algorithm and results of dynamical analysis of cracked plate subjected to moving oscillator with a constant velocity and any motion orbit. There are many surveys considering the dynamic response of the plate when there is a change in number of cracks and the stiffness of the spring k. The numerical survey results show that the effect of cracks on the plate's vibration is significant. The results of this article can be used as a reference for calculating and designing traffic structures such as road surface and bridge surface panels.


2013 ◽  
Vol 13 (01) ◽  
pp. 1350010 ◽  
Author(s):  
IOANNIS G. RAFTOYIANNIS ◽  
GEORGE T. MICHALTSOS

Telescopic cranes are usually steel beam systems carrying a load at the tip while comprising at least one constant and one moving part. In this work, an analytical model suitable for the dynamic analysis of telescopic cranes boom is presented. The system considered herein is composed — without losing generality — of two beams. The first one is a jut-out beam on which a variable in time force is moving with constant velocity and the second one is a cantilever with length varying in time that is subjected to its self-weight and a force at the tip also changing with time. As a result, the eigenfrequencies and modal shapes of the second beam are also varying in time. The theoretical formulation is based on a continuum approach employing the modal superposition technique. Various cases of telescopic cranes boom are studied and the analytical results obtained in this work are tabulated in the form of dynamic response diagrams.


1969 ◽  
Vol 59 (4) ◽  
pp. 1591-1598
Author(s):  
G. A. McLennan

Abstract An exact method is developed to eliminate the accelerometer error in dynamic response calculations for damped multi-degree of freedom systems. It is shown that the exact responses of a system can be obtained from the approximate responses which are conventionally calculated from an accelerogram. Response calculations were performed for two typical systems with three degrees of freedom for an assumed pseudo-earthquake. The results showed that the approximate responses may contain large errors, and that the correction developed effectively eliminates these errors.


2013 ◽  
Vol 49 (2) ◽  
pp. 141-162 ◽  
Author(s):  
Ramazan-Ali Jafari-Talookolaei ◽  
Maryam Abedi ◽  
Mohammad H Kargarnovin ◽  
Mohammad T Ahmadian

1997 ◽  
Vol 119 (4) ◽  
pp. 831-833 ◽  
Author(s):  
Fan Zijie ◽  
Lu Bingheng ◽  
C. H. Ku

The main objective of this work is to predict the effect of distributed viscoelastic damping on the dynamic response of multilink flexible robot manipulators. A general approach, based on the principle of virtual work, is presented for the modeling of flexible robot arms with distributed viscoelastic damping. The finite element equations are developed, and a recurrence formulation for numerical integration of these equations is obtained. It is demonstrated, by a numerical example, that the viscoelastic damping treatments have a significant effect on the dynamic response of flexible robot manipulators.


Author(s):  
Kensuke Shiomi

Through the 2011 Tohoku Earthquake or the 2016 Kumamoto Earthquake, much larger earthquakes are considered recently in the seismic designs of large steel-frame structures. When structures are exposed by these severe ground motions, partial destructions in the structures, such as damage or fracture of members could happen. Especially, the low cycle fatigue of steel structures because of the repeated load from these long-term ground motions is a serious problem. However, current seismic performance evaluation method based on nonlinear dynamic analysis considers only elastic and plastic deformation of each member, excluding the fracture of members. If this member fracture happens during earthquakes, there is considered to be many effects on the seismic performance, like the changes of the vibration property, the dynamic response and the energy absorbance capacity of structures. Therefore, the fracture of members is preferably taken into account in the seismic performance evaluation for these large earthquakes. This paper proposes the dynamic analysis method for steel-frame structures which can express the member fracture. Dynamic analyses considering and not considering member fracture under the repeated loads supposing the long-term earthquake are conducted to the FEM model of full-scale structure. By comparing each result, the effects of considering member fracture to the seismic performance such as the dynamic response and the energy absorbance capacity are discussed.


2014 ◽  
Vol 580-583 ◽  
pp. 1212-1217
Author(s):  
Qi Song ◽  
Jia Qi Guo ◽  
Wen Hua Chen ◽  
Ping Guo

Zhengyangmen gate tower is a national emphasis cultural relic unit along the north-south axis of Beijing, which is above the Beijing metro line 2. Based on dynamic analysis model of gate tower and the position of gate tower and subway, the dynamic response characteristics of gate tower induced by Beijing metro line 2 are calculated, and compared with the in-site vibration test data.


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