I am using AM-modeler in Abauqs to model powder bed fusion process. In AM-modeler, a concetrated heat source (CHS) can be selected as laser heat source. There does not exist much details on defining this CHS in simulia's documentation. In Simulia's documentation, it is described as "You can approximate the laser spot as a concentrated moving heat flux if the size of the finite elements used in a thermal analysis is significantly larger than the size of the laser spot". 
I have noticed selection of fixed time-increment has significant influence on temperature output result. It seems that decreasing time-increment keep on increasing temperature and keep on increasing until it become insanely large like 10k Celcius. But what is the ultimate limit for this time-increment? I am attaching a graph here. By any chance, time-increment is representing here laser exposure time and that probably describe temperature dependence on time-increment? or something else. Please write if you know this. 

Thanks. Rizwan. 

Abaqus ​​​​​​​