Discussion Forum

Hello all,
I have searched everywhere within Comsol discussion forum but have not found a satisfactory solution to simulate nonlinear spring effects in vibrating MEMS structures. On and off a few people have asked questions but have not been able to a) get any help, and/or b) simulate it.
I will define a simple scenario without any need for a complicated model.
Suppose I have a fixed-guided or fixed-fixed beam or a fixed-free beam. One obvious way to observe the hard-spring effect is to look at frequency response curves as is commonly done in experiments. In comsol it is possible to apply force at some boundary and generate frequency response curves. Now if you apply a very high value of force amplitude, the beam may start exhibiting nonlinear frequency response as you sweep the force frequency. This behavior has been observed exderimentally in many MEMS devices from simple beams to complicated gyro structures etc. Obviously those who are interested in knowing what conditions (e.g. force amplitude, damping etc) causes nonlinear response would want to model it in Comsol. So far, there are no tutorials or well-defined methods to do so.
Hard-spring effect can appear in many other structures (not just the example above) and it would be extremely valuable to know how to do this in Comsol. Any advise from anyone either Comsol gurus or Comsol designers would be beneficial. Please help. There must be someone out there who has explored and found a way to simulate hard-spring effect.

(1) Do we turn on Large deformations?
(2) Do we run Solid, stress-strain analysis with weak constraints on?
(3) Do we define a specific material type?