Discussion Forum

hi....
I am new to comsol and i am facing the problem in generating lamb wave in comsol.my problem is very simple in which i generate a lamb wave in aluminum plate using PZT actuator at one point and i sense voltage at other point using PZT sensor. I have done 2D plain strain modelling.the dimesions of plate are sufficiently large to avoid sensing of the reflections. i have followed following steps....
1. Created a 2D geometry.
a) Rectangle 1 - Aluminum plate
b) Rectangle 2- Piezo actuator.
c) Rect. 3- Piezo sensor.
2. Assigning material
a) Al plate (defined it as a linear elastic material)- (E,mu,density)
b) Actuator and sensor- PZT 5A
3. In piezoelectric devices.
a) Coordinate system selected for PZT material as XZ.
b)Linear elastic material - Rect.1(Aluminum)
c)Ground - edge of sensor and actuator which is in contact with plate.
d)Electric potential - Hanned voltage applied over the top edge of actuator.
4. Meshing- Used a mapped mesh of size 0.2 mm and divided the actuator and sensor in 3 layers.
5.Study-
a) step1 time dependent - range(0,1.0e-7,1.5e-4)
b) Time stepping - Strict
and i have solved it. when i sense the output at the center point of the sensor i found out that the maximum voltage is closed to 5 volts. and ase per the paper which i am validating it should be close to 3 volts. I have also modeled it in abaqus and i got rigth results inn abaqus.
I am having an answer for a simple cantilver beam wich is like two layer beam with one layer of piezoelectric material and other of that of aluminum with this model also i found out the anaswer in abaqus and available answers are matching but the answer in COMSOL and abaqus are not matching..

Pls go thru the attached model and tell me where i am going wrong ......

thanks in advance.
pramod