Vibration frequency of a clamped beam with a central
length of beam in µm
wid width of
beam in µm
thickness of beam in µm
mlen length of the mass in
mwid width of the mass in
mthc thickness of the
mass in µm
den density of
the material in kg/m3
ymod Young's modulus of the
material in GPa
denoting the selected result.
Use 1 for normal vibration frequency, 2 for lateral vibration
frequency and 3 for angular vibration frequency
An inertial mass suspended from two clamped beams is a structure
often used in MEMS accelerometers and other motion sensitive
devices. A typical structure is as shown above. It could be
considered as a typical spring mass system. Three different
vibration modes are discussed here. Vibration perpendicular to the
plane of the mass, lateral vibration of the mass and a torsional or
angular vibration of the mass about the beam axis are discussed.
Use this form to estimate the vibration frequencies of normal,
lateral and angular modes. The influence of the beam and mass
dimensions on these modal frequencies could be understood.
The plot shows the amplitude frequency
relationship for the given beam-mass. It shows the first resonance
frequency as a sharp rise in amplitude. Using the cross hair tool,
the resonant frequency and the corresponding relative amplitude can
-The default material is Silicon with a Poisson's ratio of
-The beam has uniform cross section.
-The weight of the beam and mass is uniformly distributed.
-There is no other load acting on the beam other than the weight of
the mass and its own weight.
-The bending of the mass is negligible
-Damping is not involved.
Mechanics > Vibration > Free vibration > Clamped beam >