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Modal testing

About: Modal testing is a research topic. Over the lifetime, 4047 publications have been published within this topic receiving 64772 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the effect of linear joint characteristics on the vibration of a free-free, three-joint beam model was analyzed, and it was shown that increasing joint damping increases resonant frequencies and modal damping, but only to the point at which the joint gets "locked up" by damping.
Abstract: Analysis of the effect of linear joint characteristics on the vibration of a free-free, three-joint beam model shows that increasing joint damping increases resonant frequencies and modal damping, but only to the point at which the joint gets «locked up» by damping. The maximum amount of passive modal damping obtainable from the joints is greater for low-stiffness joints and for modal vibrations where large numbers of joints are actively participating. A joint participation factor is defined to study this phenomenon. Analysis of the nonlinear three-joint model, with cubic spring at the joints, shows classical single-degree-of-freedom nonlinear response behavior at each resonance of the multiple-degree-of-freedom

46 citations

Journal ArticleDOI
TL;DR: It is suggested that natural frequency is an important parameter for assessing the periodontal condition and that the modal testing technique is a useful supplemental method for assessing the attachment conditions of theperiodontium.
Abstract: Background: When measuring periodontal disease, various types of equipment for making objective measurements of tooth mobility have been proposed. However, these devices and methodology are insufficient in terms of reliability. An innovative method using vibrational theories to assess the periodontal attachment level of natural teeth is presented in this study. Methods: Modal testing technique, a non-destructive and time-saving method, was used for non-invasive and quantitative measurement of the natural frequencies of the upper central incisor in vivo and in vitro. A finite element model was established, and modal testing experiments were simulated to assess the relationship between bone level and teeth. Results: The first dominant natural frequency of healthy human upper central incisors ranges from 710 Hz to 3,360 Hz, with an average of 1,701 ± 679 Hz. Both in vitro experiment and finite element simulation showed that lowering of the attachment level causes a significant decrease in the natural frequen...

46 citations

Journal ArticleDOI
TL;DR: In this paper, the structural-dynamic-modification theory is used to derive a set of equations, from which all the existing formulations can be derived, and two new exact formulations for the scaling factors, one for the nonmodified structure and the other for the modified structure, are provided.

46 citations

Journal ArticleDOI
H. Irretier1
TL;DR: In this paper, the mathematical foundations for experimental modal analysis of rotating structures are presented, characterised by non-symmetric and time-varying matrices and solved by modal transformation to derive impulse and frequency response functions, which form the basis of modal identification algorithms in time and frequency domains, respectively.

46 citations

01 Sep 2000
TL;DR: In this article, two possible methods, namely dynamic FRF compensation and compensation by residual modes, are discussed for vehicle FE data, more specifically to the coupling of a vehicle subframe with a body-in-white.
Abstract: FRF based substructuring (FBS) predicts the dynamic behaviour of a coupled system on the basis of freeinterface FRFs of the uncoupled components. The modal synthesis technique determines the dynamic behaviour of a coupled system on the basis of a normal mode description of the uncoupled components. This paper gives a brief description of the theoretical background of these techniques. When using these techniques it is important to take into account the error due to modal truncation. This error can be significantly reduced by application of compensation methods. This paper discusses two possible methods, namely dynamic FRF compensation and compensation by residual modes. In order to evaluate the FBS and modal synthesis techniques and the compensation methods, they are applied to vehicle FE data, more specifically to the coupling of a vehicle subframe with a body-in-white. In the case of multi-component coupling with high frequency resolution and bandwidth the results are in favour of modal synthesis but in the case of frequency dependent joints and the need for easily obtainable interface forces the results are in favour of FBS.

46 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202367
2022164
202141
202059
201967
201878