The　closure　behavior　of　fractured　rock,　which　is　a　crucial　characteristic,　is　challenging　to　simulate　accurately　using　commonly　employed　numerical　models.　To　address　this　issue　and　accurately　replicate　the　nonlinear　mechanical　behavior　of　rock,　we　propose　a　modified　joint　element　constitutive　model　for　the　finite-discrete　element　method　(FDEM).　The　modified　model　resolves　the　stress　on　both　sides　of　the　crack　by　considering　the　aperture　of　the　broken　joint　element　instead　of　contact.　Additionally,　Joint　elements　with　virtual　opening,　which　are　referred　to　as　preprocessed　joint　elements　(Pre-JEs),　are　implemented　in　this　model.　We　extensively　discuss　two　parameters　associated　with　Pre-JEs　to　elucidate　their　impact　on　the　nonlinear　mechanical　behavior　of　rock.　Our　findings　demonstrate　that　the　incorporation　of　Pre-JEs　leads　to　a　reduction　in　the　compressive　strength　of　rock.　Furthermore,　increasing　the　thickness　of　Pre-JEs　results　in　the　softening　of　the　elastic　modulus.　Moreover,　we　have　made　improvements　to　the　conventional　calibration　procedure　for　input　parameters　in　FDEM.　By　employing　our　enhanced　methodology,　we　successfully　reproduce　the　crack　closure　behavior　and　peak　strength　of　Lac　du　Bonnet　granite　using　the　proposed　model.　©　2023　Elsevier　Ltd