：　The　U-shaped　steel　plate　damper　has　the　advantages　of　good　energy　dissipation　capacity，energy　dissipation　by　its　own　deformation，stable　performance，convenient　fabrication，and　low　price.　However，it　also　has　problems　such　as　low　initial　stiffness　and　low　bearing　capacity.　Therefore，a　U-shaped　metal　yield　damper　with　T-shaped　section　（hereinafter　referred　to　as　the　damper）　was　proposed　in　this　study.　Based　on　the　virtual　work　principle　and　Castigliano＇s　Second　Theorem，the　theoretical　formulas　of　the　yield　strength　and　initial　stiffness　of　the　damper　were　established.　Based　on　the　nonlinear　mixed　hardening　constitutive　model　and　the　three-dimensional　ductile　fracture　criterion，a　finite　element　model　of　the　damper　considering　material　ductile　fracture　was　established.　This　study　focused　on　the　stiffness，strength，energy　dissipation　capacity　and　failure　mode　of　the　damper.　Parametric　analysis　quantified　the　influence　of　geometric　dimensions　and　other　parameters　on　the　mechanical　properties　of　the　damper.　The　research　shows　that　the　stiffness，strength　and　energy　dissipation　capacity　of　the　damper　are　significantly　improved　as　compared　with　those　of　the　U-shaped　damper.　The　web　width，height，flange　width　and　thickness　of　the　T-shaped　section　of　the　damper　have　significant　impact　on　the　mechanical　properties　of　the　damper.　©　2024　Tongji　University.　All　rights　reserved.