A new method to evaluate the stress concentration factor of a plate with drilled holes

The thesis introduces a new method of estimating the stress concentration factor in a plate with two or three drilled holes. It is known, that stress concentrations are one of the biggest problems to avoid when designing any kind of structure. One drilled hole is decreasing the strength of a whole structure at least three times, which makes the production cost and amount of needed material more, and to avoid stress concentration different methods are used, for example, adding more material (e.g. welding) or other connections (e.g. bolts, rivets, etc.), which creates more stress concentrations. In this work a new approach is checked. It states, that more holes drilled near the main hole will decrease the stress concentration factor of the whole structure, which happens because of the stress interaction. But for now only few global recommendations have been given in previous studies, so this phenomena was studied more in cases with two and three drilled holes. Body force method, which is another numerical method to solve engineering problems, was used to make a Matlab code, which can be easily used by anyone to evaluate the stress concentration factors. Finite element analysis confirmed the code working correctly and at the end it was confirmed that auxiliary holes can reduce stress concentration factor from value 3 up to value 2.3 at least. Few recommendations were given and new questions were set for further studies