Investigation of the Relation Between Tube Spacing and Tube Sheet Deformation in Heat Exchangers Due to the Mechanical Rolling Process: A Numerical Study

The focus of this paper is the validation and comparison of simplified numerical models of the mechanical rolling process used in tube to tubesheet joints. The investigated models is an axisymmetric model and planar models with plane strain and stress. There are different pros and cons for the different simplified models and therefore they are compared to an experiment where all geometries are measured before and after expansion. This comparison gives an insight into when the different models are valid. The models investigated is an axisymmetric model, a simple 2D expansion model with both plane strain and stress assumptions. Therefore, it is desirable to investigate how close these simplified models can predict the geometry changes after expansion measured in the experiment. The conclusion of the paper is that a planer model with plane strain is the best model at predicting the actual deformation after expansion.