This　paper　presents　a　numerical　study　on　the　plastic　hinge　behavior　and　rotation　capacity　of　concrete　columns　reinforced　with　a　combination　of　steel　bars　and　fiber-reinforced　polymer　(FRP)　bars.　A　meso-scale　numerical　model,　which　considers　the　internal　heterogeneity　of　concrete　and　bond　behavior　between　concrete　and　longitudinal　reinforcements,　was　developed　and　validated.　The　failure　modes,　lateral　load-displacement　responses,　and　the　physical　plastic　hinge　lengths　of　hybrid　steel-FRP　reinforced　concrete　(SFRC)　columns　were　investigated　and　compared　with　those　of　conventional　steel-reinforced　concrete　columns.　The　results　indicated　that　the　steel　yielding　zone　and　curvature　localization　zone　of　SFRC　columns　with　FRP　longitudinal　bars　were　enlarged,　due　to　the　relatively　low　modulus　of　FRP　bars.　After　that,　a　parametric　analysis　was　performed　to　study　the　plastic　hinge　length　of　SFRC　columns　with　respect　to　the　nominal　area　ratio　of　FRP　longitudinal　bars,　shear　span-to-depth　ratio,　axial　load　ratio,　and　longitudinal　reinforcement　ratio.　A　new　empirical　model　was　proposed　to　predict　the　equivalent　plastic　hinge　length,　which　was　subsequently　integrated　into　an　analytical　method　for　predicting　the　ultimate　rotation.　The　comparison　of　predictions　with　simulation　and　test　results　demonstrated　the　accuracy　of　both　the　proposed　empirical　model　and　analytical　method.　©　2024　Elsevier　Ltd