Is it allowed to submit accepted and published journal articles in Elsevier, to arXiv? As arXiv allows submitting research articles which helps in increasing its visibility. I was wondering if it is alright to submit accepted and published journal articles in Elsevier (Expert Systems with Applications, International Journal of Medical Informatics) to arXiv?
You can easily find the answer following the author guidelines of Elsevier, starting from the link you provided. On https://www.elsevier.com/about/company-information/policies/sharing they explicitly state:


  Authors can update their preprints on arXiv or RePEc with their accepted manuscript .