**Author details**

Seung-Bok Choi\* , Sung Hoon Ha and Juncheol Jeon

\*Address all correspondence to: seungbok@inha.ac.kr

Smart Structures and Systems Laboratory, Department of Mechanical Engineering, Inha University, Incheon 402-751,, Korea

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[14] Machejowski, J. M. (1989). Multivariable feedback design. Addison-Wesley Publish‐

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**Author details**

Seung-Bok Choi\*

**References**

, Sung Hoon Ha and Juncheol Jeon

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*tive Structures and Technologies*, 182-194, (Seoul, Korea).

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**Chapter 6**

**Recent Advances on Force**

http://dx.doi.org/10.5772/51650

**1. Introduction**

recently [1].

freedom (MDOF) systems.

**Identification in Structural Dynamics**

N. M. M. Maia, Y. E. Lage and M. M. Neves

Additional information is available at the end of the chapter

This chapter presents recent advances on force identification for structural dynamics that have been developed by the authors using the concept of transmissibility for multiple degree-of-

Being applied for many years only to the single degree-of-freedom (SDOF) system or to MDOF systems in a very limited way, the transmissibility concept has been developed along the last decade or so in a consistent manner, to be applicable in a general and complete way to MDOF systems. Various applications for MDOF systems may now be found, such as evaluation of unmeasured frequency response functions (FRFs), force identification, detection of damage, etc. A review of the multiple applications of the transmissibility concept has been published

It is the application of this generalized transmissibility concept to both the direct and inverse force identification that is described along this chapter. The direct problem is understood as the one where one knows the applied forces and wishes to estimate the reactions at the supports; the inverse force identification problem is when one wishes to determine how many

To determine the location and magnitude of the dynamic forces that excite the system is an important issue in structural dynamics [2, 3], especially when operational forces cannot be directly measured, as it happens at inaccessible locations [4, 5]; it is often the case that transducers cannot be introduced in the structure to allow the experimental measurement of the external loads and only a limited number of sensors and positions are available. The identification of forces from vibration measurements at a few accessible locations is a

> © 2012 Maia et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2012 Maia et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

distribution, and reproduction in any medium, provided the original work is properly cited.

forces are applied, where they are applied and which are their magnitudes.
