Experimental and numerical investigation of impacting cantilever beams: Second mode response

Krishna, I. R. Praveen; Padmanabhan, Chandramouli

doi:10.1016/j.ijmecsci.2014.12.013

Cited by 13 publications

(9 citation statements)

References 25 publications

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“…A number of papers are available in the literature dealing with elastic or elasto-plastic contact-impact problems; most of these works recognize that the Hertzian theory can be applied for an elastic impact. 33,34 Marghitu et al. 35 studied the impact of a rigid and flexible body against a half-space and analyzed the motion after the impact with the consideration of transverse elastic displacement.…”

Section: Introductionmentioning

confidence: 99%

Comprehensive analyses of the elasto-plastic oblique contact-impact with vibration response

Meng

Wang

2018

Proceedings of the Institution of Mechanical Engineers, Part K:

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Contact-impact between different surfaces is a ubiquitous phenomenon especially in the mechanical systems. Previous work of authors indicated that the effect of longitudinal and/or transverse vibration response during the motion and dynamic modeling cannot be neglected for the elasto-plastic contact-impact events. In this study, further analyses were performed to characterize the contribution of longitudinal and transverse vibration responses during the elasto-plastic oblique contact-impact, and the formula to calculate the influence factor of vibration, ξ, was proposed based on the contact force with different vibrations during the impact. The momentum theorem and assumed mode method were used to develop the equations of motion of a flexible bar with a solid flat surface. Simulation results were compared with experimental results reported in the literature to verify the accuracy of the established model. The tangential and normal velocities of the contact point after the impact were compared with the simulations for different vibration cases, and the comparison between the simulations and the experimental results had yield encourage results. For different elasto-plastic materials, three critical initial impact angles had been found from the simulation to determine whether the flexible bar slides or sticks the flat surface. Although considering the effect of vibration response during the motion and dynamic modeling is very significant, increasing the number of shape functions did not effect the result significantly. The longitudinal and transverse vibration responses were found to effect the normal and tangential velocities of the contact point after the impact, respectively. Moreover, it had been shown that for the oblique contact-impact with sliding, considering the response of longitudinal and transverse vibration at the same time is more reasonable than other cases, which also reveals that, in this case, there is a good agreement between the simulation and experimental results. Besides, the mathematical expression on the influence factor of vibration depending on the initial velocity also had been obtained by a numerical analysis. This work can provide useful insights for dynamic modeling of complex multi-body systems during the contact-impact.

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Section: Introductionmentioning

confidence: 99%

Comprehensive analyses of the elasto-plastic oblique contact-impact with vibration response

Meng

Wang

2018

Proceedings of the Institution of Mechanical Engineers, Part K:

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“…The impact with clearance is a very common dynamic phenomenon in mechanical system, such as shrouded blades 1,2 and gear systems, 3 which can cause the complicated nonlinear vibration characteristics, and many researchers 1,2,4–6 have discussed the dynamic characteristics of vibro-impact system with clearance theoretically and experimentally. Many mathematical models were proposed to describe the dynamic phenomena of vibro-impact systems, such as lumped mass models, 7–15 beam-stop impact models, 2,4,6,16–22 and beam–beam impact models, 1,5,23,24,28 which enriched the research results of vibro-impact system with clearance.…”

Section: Introductionmentioning

confidence: 99%

“…Besides the vibro-impact analysis of simple impact dynamic model, the vibro-impact responses of beam–beam impact model also attracted a lot of interests. 1,5,26,27 On the basis of Euler–Bernoulli beam theory, the nonlinear dynamic characteristics of shrouded blade with clearance impact were analyzed, 1 and the authors extended their researches to analyze the similarities and differences of the two impact models, beam-stop impact model, and beam–beam impact model, in shrouded blade impact systems. 26 Andreaus et al.…”

Section: Introductionmentioning

confidence: 99%

“…Except for these models, finite element method is also used to establish the dynamic models of beam-type structures or other more complicated blade structures. 5,27–36 Knudsen and Massih 33 established a finite element model (FEM) of a Bernoulli-type beam with springs, and analyzed the vibro-impact response of the system with loose supports under a harmonic load. Krishna and Padmanabhan 5,34 established the FEMs of blades, and studied the vibration responses of the flexible beam undergoing vibro-impact with two other flexible beams at its free end, and discussed the steady state characteristics of the beams near the first and second modes, and verified the numerical simulation results by experiment.…”

Section: Introductionmentioning

confidence: 99%

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Numerical and experimental investigation on the vibro-impact responses analysis of shrouded blade

Cui

Jin

et al. 2018

Journal of Low Frequency Noise, Vibration and Active Control

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A finite element model of shrouded blades is established to analyze the vibration responses due to the impact between adjacent blades. In the finite element model, the blade and the shroud are simulated using beam element and lumped mass, respectively. On the basis of the finite element model, a beam-beam impact model is developed to study the vibroimpact responses of shrouded blades. By comparing the natural frequencies and vibration responses, the finite element model is verified by an analytical model. In addition, a test rig is also set up to compare the results obtained from simulation and experiment, and the influences of different parameters such as shroud gap, excitation amplitude, and excitation frequency on the vibro-impact response are analyzed by finite element model and experiment. The results obtained from finite element model and experimental model indicate that the impacts between adjacent shrouded blades weaken with the increase of the shroud gaps and excitation frequency, and the vibro-impact responses between shrouded blades become strong with the increasing excitation amplitude. The results also show that the secondorder flexural vibration of blade is easier to be excited and the super-harmonic resonance phenomenon closed to the second-order flexural natural frequency is more significant than that at other flexural natural frequencies.The reason is that the position of the external force applied on shrouded blade accords with its second-order flexural vibration mode.

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“…Prasad and Seshu [16] studied experimentally modal characteristics of beam made of different materials such as Steel, Brass, Copper and Aluminum. Krishna and Padmanabhan [17] observed second mode response of flexible cantilever beam under vibro-impact at free end. Lasowicz and Jancowski [18] studied modal characteristics of a composite aluminum cantilever beam with a polymer adhesive and reported observations on effect of polymer adhesive on damping properties.…”

Section: Introductionmentioning

confidence: 99%

Effect of Clamping Torque on Large Deflection Static and Dynamic Response of a Cantilever Beam: An Experimental Study

Konagai

Noorzad

Eskandari‐Ghadi

2018

IJET

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The present paper reports an experimental study on the effect of finite clamping on static and dynamic characteristics of cantilever beam. The experiment is carried out with two different beams, each of which is clamped at two different locations resulting in two different geometry settings. Under each of these four settings, specimen is clamped under two different torque ratings giving rise to different finite clamping effect. Under the eight settings, coordinates of tip point under static loading are measured directly using scales and plumb at each load step; whereas, complete deflection profiles of loaded beam under each static load step are obtained through post-processing of images captured during experimentation. Such image processing is carried out manually using AutoCAD®and in-built AutoLISP®software. Strain measurements at each static load step are carried out by using strain gauge, a universal data acquisition system and the associated Catman Easy®software. To obtain loaded free vibration characteristics, loaded beam under each setting is disturbed by a rubber hammer and its dynamic response is recorded from strain gauge signal through Catman Easy®software. These dynamic strain readings of loaded beam are post-processed and FFT plots are generated in MATLAB®software and first two loaded natural frequencies of beam under each setting are obtained. Finally, effects of clamping torques on the static strain and deflection results and loaded natural frequencies for beam settings with the four different thickness to length ratios are reported in a suitable manner. The result reported may be useful as ready reference to develop a theoretical model of clamped beam like structures incorporating the effect of finite clamping.

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Experimental and numerical investigation of impacting cantilever beams: Second mode response

Cited by 13 publications

References 25 publications

Comprehensive analyses of the elasto-plastic oblique contact-impact with vibration response

Comprehensive analyses of the elasto-plastic oblique contact-impact with vibration response

Numerical and experimental investigation on the vibro-impact responses analysis of shrouded blade

Effect of Clamping Torque on Large Deflection Static and Dynamic Response of a Cantilever Beam: An Experimental Study

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