In　order　to　accurately　simulate　structural　fatigue　crack　damage,　the　non-linear　contact　model　was　selected　and　verified　to　be　suitable　for　the　fatigue　crack　simulation　in　cantilever　beam.　The　influence　of　damage　severity　and　location　on　harmonic　vibration　responses　were　revealed.　Moreover,　the　damage　identification　indexes　based　on　harmonic　excitation　response　were　constructed,　and　the　effectiveness　used　to　identify　fatigue　crack　damage　was　validated.　The　results　reveal　that　contact　model　is　effective　in　simulating　fatigue　crack　and　sensitive　to　nonlinear　fatigue　crack　through　the　comparative　analysis　of　harmonic　vibration　response　of　intact　structure　and　damaged　one.　For　the　vibration　responses　of　beam　with　different　damage　severities　and　locations,　the　greater　the　damage　severity　is,　and　the　closer　the　damage　location　is　to　the　fixed　end,　the　more　obvious　the　non-linear　vibration　characteristics　presents.　Two　damage　indicators　including　distortion　value　of　phase　spectrum　()　and　proportion　of　super/sub-harmonic　amplitudes　(Dd)　are　applied,　which　can　effectively　characterize　the　change　of　fatigue　crack　with　different　damage　location　and　severity.　Furthermore,　contact　model　presents　stronger　non-linear　information　compared　with　bilinear　model,　which　is　more　suitable　for　fatigue　damage　simulation.　©　2022　Xianqiang　Wang,　et　al.