[Dynamics] Ultrasonic Welding of thermoplastics

I am going to simulate the well-known welding process i.e.
ultrasonic welding process for thermoplastics using ANSYS. I am using ABS first
of all. My sample dimensions are 30*40*1 and one of these two parts will be
having an energy director of triangular shape at its centre with an overall
thickness of 1.5 being equally distributed from the centre.

The parts to be welded are placed on the anvil and after
proper fixturing, ultrasonic vibrations are applied at the upper part under a
pressure of 2.0775E6.

With reference to FEA, I am using three approaches to
simulate this process,

1.      
I have performed a simplified thermoviscoelastic
analysis to get the heat flux then now I am able to find out the temperature
due to viscoelastic heating. I am little bit satisfied with it.

2.      
Couple-Field Analysis (Themo-Mechanical) by
Direct Method

In this case, I used both 2D and 3D
geometries with Plane223 and Solide227 as Coupled-Field Elements and Plane 182 and
Solid92 as Solid Elements. My approach here was to output temperatures at the
frictional contact between the two parts to be welded under ultrasonic
vibrations and by applying directly these temperature on elements Plane182 or
Solid92 to have mechanical analysis.  As
the chances for these elements used in this approach, are huge to mix themselves
with electrostatic analysis giving volt ouput, I have left this approach.

3.      
Couple-Field Analysis (Themo-Mechanical) by Load
Transfer Method.

Now a days, I am also using this method
instead of direct method, and I have selected the elements and material
properties.

In short, I am relying on 1st and
3rd approach for my simulation.

I want to ask you two things:

·        
Can Prony series give me the heat developed at
the interface of parts to be welded, due to viscoelastic heating and by giving coefficient
of friction.

·        
I have also selected another viscoelastic model
for simulation but in this case, I am also wondering whether I may be able to
get temperature or heat at the end of welding process? For this what I can
output is Stress relaxation, creep or I can find out failure of material based
on some failure criteria.