Numerical simulation of accumulated steam generator tube sheet damage and loose part impact distributions

An experimental research program into the loose part damage process identif ied important mechanisms that govern accumulated lease part damage to steam generator tube sheets, Relationships were developed to quantify damage due to single and multiple impacts, including such effects as tube end open di ameter reduction and tube end contour deformation. These experimental inves tigations have led to the development of a computational model for estimati ng loose parr impact damage on steam generator tube ends. Comparisons to ex perimental data shaw the loose part damage model to be a good approximation of actual loose part impact damage and provide a convenient and quantitati ve linkage between loose part impact properties and damage. Impact damage e ffects are local effects that depend only on the single impacts and impact overlaps in a small region of interest. The damage can be directly related to local impact density. Since in general the local impact density on a ste am generator tube sheet is unknown, a model developed to simulate lease par t impact distributions as a function of operating conditions is described.