Abaqus FEA Heat Transfer analysis - Over constrained nodes

[FFarnan1]

Hello,
I am carrying out 1D - heat transfer analysis on 3 pieces of timber glued together exposed to fire, modelled by the interaction of convection and radiation on the exposed surface. After a certain amount of time the first layer of timber falls off (Model change interaction) and the interactions of convection and radiation are redefined on the newly exposed surface. (This works perfectly fine for the first fall off) but when it comes to the fall off of the second piece of timber falling off it doesn't run the step:
"too many increments needed"
A brief overview of the steps:
Initial - predefined temperature field of 20 degrees, conductance interaction between the three pieces of timber
Step 1 - Convection and radiation applied to exposed surface following temp/time curve
Step 2 - Model change (removal of the first layer), redefined convection and radiation on the new surface
Step 3 - Model change (removal of the second layer) and again redefined convection and radiation on the newly exposed surface

I've suppressed the third step it works fine. And the conductance is working ok. Also checked the .msg file and it says the nodes are over-constrained

Can anyone guide me into what might be going wrong?
I am happy to provide .cae file or more information if needed

Many Thanks

 

[FEA way]

Which type of elements are you using ? Maybe you could try with the newly implemented progressive element activation and progressive cooling on evolving surfaces. Those functionalities are meant primarily for additive manufacturing process simulations but they have other uses too. They can often be used in place of old and inefficient model change technique.