Pots vibrants

Modal Shakers

Modal testing can be performed with modal hammers or shakers. If high-frequency excitation content or signal controlled testing is desired, then modal shakers are the only excitation solution. Dewesoft modal shakers are lightweight and powerful modal shakers which can go up to 15,000 Hz and provide force levels up to 440N with a maximum 25mm stroke.

Advantages:

• Modal stinger can be easily adjusted by the through-hole armature
• Lightweight, durable, portable and easy to use
• Adjustable trunnion base provides high flexibility
• Up to 25mm stroke and broad frequency range

Applications for Modal Shakers

Modal shakers can be used for Modal testing and Structural Dynamics. 

The series of Dewesoft modal shakers covers a wide range of structures for dynamic characterization from electronic boards and sub-components to machinery, vehicles and aircraft, even constructions.

• Components, Machinery, Vehicles, Aircraft, and constructions
• Aerospace and
• Automotive

Modal Testing is a prerequisite for design and product validation in aerospace and automotive industries as well as many others.

Modal Test

In real life applications, machine parts and mechanical systems are rarely under static loading. Most of the time they are excited by dynamic loads. The structure responds to these dynamic loads according to its dynamic parameters such as natural frequencies and mode shapes. Therefore, an engineer has to have a solid insight into the dynamic behaviour of the structure which has been designed. The process of finding the dynamic behaviour of a structure is called structural system identification.

Structural system identification consists of finding the transfer function of the system which is established by finding the modal parameters of the structure such as, natural frequencies, damping, modal vectors, and residues.

The transfer functions of a structure can be obtained by mathematical modelling or by experimental methods. The experimental way to obtain the transfer function of a structure is achieved by measuring the response of the structure to a measured input. The responses are generally acceleration and the inputs or excitations are generally impulses or random/sine signals.

More information on the Modal Analysis application page.

Modal Test

The impulse signal is easily generated by a modal hammer with a force transducer attached at its tip. The random or sine signal excitation requires modal shakers. Moreover, if high-frequency excitation content or signal controlled testing is desired, then modal shakers are the only excitation solution. Dewesoft modal shakers are lightweight and powerful modal shakers which can go up to 15,000 Hz and provide force levels up to 440N with a maximum 25mm stroke.

The modal shaker is attached to the structure and the desired excitation signal is applied to the structure via a signal generator. In the meantime, the responses of the structure are
measured and Frequency Response Functions are calculated which are used in the Modal Analysis calculations.

More information on the Modal Analysis application page.