Modal testing: Difference between revisions

Revision as of 21:07, 21 March 2011

Revision as of 21:08, 21 March 2011

Line 21:

For large civil engineering structures much larger shakers are used, which can weigh 100[[kg]] and above and apply a force of many hundreds of [[newtons]]. Several types of shakers are common: rotating mass shakers, electro-dynamic shakers, and electrohydraulic shakers. For rotating mass shakers the force can be calculated from knowing the mass and the speed of rotation; for the electro-dynamic shaker the force can be obtained through a load cell, or an accelerometer placed on the moving mass of the shaker. Shakers can have an advantage over the impact hammer as they can supply more energy to a structure over a longer period of time. However, problems can also be introduced; shakers can influence the dynamic properties of the structure and can also increase the complexity of analysis due to [[window function|windowing]] errors.

==External links==

*[http://www.mpihome.com/pdf/soa_structural_dynamics_testing.pdf Structural Dynamics Testing/Modal Analysis]

*[http://www.pcb.com/techsupport/tech_hammers.php Impact Hammer Selection Guide]

*[http://www.lmsintl.com/modal-analysis A Brief Introduction to Modal Analysis]

==See also==

*[[Vibration]]