In　order　to　ensure　that　aircraft　performance　satisfies　the　damage　tolerance　design　requirements,　it　is　necessary　to　assess　its　residual　strength.　This　paper　deals　with　the　R-curve　and　residual　strength　analysis　of　welded　thin-walled　structures　for　aircraft　fuselage　applications　made　of　Al　6156-T4　alloy.　The　experimental　results　have　been　used　to　verify　the　proposed　analysis　route　for　the　residual　strength　prediction.　In　addition,　the　crack　propagation　paths　are　detected　when　the　crack　through　the　stringer　and　the　crack　growth　rates　are　measured　in　two　directions.　The　residual　strength　is　predicted　for　one-bay　and　two-bay　thin-walled　structure　with　variety　initial　crack　length　using　different　criteria.　The　results　show　that　crack　branching　(into　skin　and　stringer)　when　crack　growing　approached　to　the　stringer　in　a　perpendicular　form.　It　is　found　that　the　residual　strength　is　underestimated　using　the　net　section　yield　criteria　for　the　residual　strength　prediction.　In　particular,　the　prediction　based　on　SINTAP-FITNET　evaluation　system　using　parameters　CTOD-δ5　is　more　accurate　than　using　K　curve　method.　©,　2015,　AAAS　Press　of　Chinese　Society　of　Aeronautics　and　Astronautics.　All　right　reserved.