by a stress increasing factor of for example 2 6 optionally evaluation stresses which may be present can be rescaled accordingly detailed simulations were not carried out using the model described in fig5 but the geometry of the heat exchange profiles 2 was modeled as in fig4 according to reality the resulting computation cost is so high that only small sections from plate type heat exchangers can be computed thus the thermally induced stresses are known the three dimensional distribution of the total stress is determined by application of the operating pressure and stress boundary conditions see below 2 example for sequence of a simulation according to the invention a representation of the plate type heat exchanger geometry according to the simulation software marc used later is prepared by a preprocessor program mentat for configuration data files both marc and also mentat are software products from macneal schwendler corp msc alternatively finite element systems can also be used for carrying out simulation within the framework of the invention a plate type heat exchanger can have several different passage types which can differ for example in the heat exchange profile fins a first configuration data file contains the stacking sequence of the passages other configuration data files each contain geometry information about the separating plates 1 covers 5 beams 4 and other geometrical properties of the plate type heat exchanger passages can also be divided into zones in which for example a medium flows and heat is exchanged with adjacent passages active zones or in which a medium does not flow passive zones these zones can also be described in the configuration data file the passages are each divided into two sections lying on top of one another the division corresponds to the.