pronunciation US-UK in words like "semi"

I am trying to find a document that explains pronunciation differences in /E/ and /I/ sounds between UK and US styles. I think US pronunciation has /'sɛmay/ a lot more often than UK /'sɛmi/. Where can I find a document explaining this difference?

Maybe my 3-year residence in England 35 years ago influenced my American accent, but I use both forms of pronouncing "semi". When using it as a spoken abbreviation for "semi-trailer" I say "sem eye". For "semicircle" I say "sem ee". And some other times I say "sem eye circle".

I don't think there is a fixed rule. I think it is highly individualized.

Keep in mind that there is not one US accent, just like there isn't just one UK accent. They're both collections of dialects and accents. So within the US you could have regional accents where some words, like semi, are pronounced similarly to the UK, and vice versa.

If by US accent you mean the New York accent, and by UK you mean BBC English, then the US version - as per wikitionary, at least - is /sɛmaɪ/, and the UK being /'sɛmi/, as you posted

The reason why US English differs from UK English in the ways that it does is constantly disputed. There are theories that US English is actually more similar to the English used at the time of its colonisation, others argue that it adapted due to so many other languages interacting, at the beginning.

I haven't studied it in detail, but the American-British British-American Dictionary does have sections on pronunciation & dialects.