The word "Eigenstrain" was introduced by T. Mura in 1987 , yes quite recently, on the basis of the German words "Eigenspannungen" and "Eigenspannungsquellen" . Eigenstrain, simply described, is a residual strain produced without an external force. Thermal expansion and phase changes are Eigenstrains. For example when a hot piece of glass is put under cold water or vice versa, it can break because of this Eigenstress.

APW ( Powder Bed Programmer ) , the new role in 2019x with proven apps in it, engages with Eigenstrain method enabling additive engineers to quickly apply a library of constraints to a scanned path and simulate to predict the build up of the part displaying areas of anomalies. These anomalies that can potentially affect the quality of the part can be addressed virtually by adjusting scan path strategies and re-simulating the build up.

APW is designed for additive process engineers who are not really Simulation Analysts !!

Take a look below at the residual stress comparison between the Eigenstrain results with the standard Thermo-mechanical manual set-up results. They are almost coinciding in the graph, thus proving the Eigenstrain method of analyzing a print is as good as doing it the elaborate Thermo-mechanical way. The block experimental test data provided by Renishaw compares these 2 methods.