Shaker Selection

In general, Newton’s second Law is applied when choosing a vibration system. Sinus vibration and shock tests depend on the following formula.

F= ma 

F= (m0 +m1+m2+…)a

F = Force (N)

m = mass (kg) 

a= acceleration (m/s2).  The peak (value) of the acceleration.

The maximum acceleration depens on the applied force and the weight of the sample. The mass value (m) should include all moving masses involved in the actual test setup such as:

m= shaker armature (m0)+ test specimen (m1) + test fixture (m2) + special adapters (head expander or slip table) (m3) .

• It may differ to obtain a correct mass (m) value for vertical axis testing and for horizontal axis testing. In horizontal axis case, counter force will be applied to the shaker. Therefore, it is necessary to ensure proper fixation of the shaker or use a horizontal slip table. In both cases it is very important to to include all various components required for the test.

• Two important factors regarding the level (g) given in the test condition include the maximum velocity and maximum displacement (stroke) required for the test.

Permanent Magnet  Shaker can be used for functionality tests, endurance tests and sensor calibration tests.

The structure is mounted on the shaker.

Modal Shaker and Inertial Shaker can be used for excitation of structure for dynamic behaviour detection.

Modal shakers are attached to the structure whereas inertial shakers are attached on the structure.

Small shakers are preferred for small structures, big shakers are preferred for big structures.

It should be known how much force is needed for the application. If the force is insufficient, more shakers could be used for modal testing. For endurance tests bigger shakers should be preferred.