Is this grammatically correct?

The aim of the first part of this work/thesis is studying several kinds of weaknesses/fragilities that often affect elderly people/persons. The research investigates biopsycological aspects and shows the evaluation weaknesses models/schemes.

Hi, if you write the text in an active voice it is easier to read, but this is also a matter of taste.

The aim of the first part of this thesis is to study [here it depends on what you are actually looking at] which weaknesses often affect elderly people. I/we will examine the biopsychological aspects and demonstrate the weaknesses associated with the evaluation model [if I understand correctly, I think you should mention the specific model you are using]