The behaviour of timber-steel hybrid beams for buildings is very complex because of the combination of the two very different materials that are wood and steel. Numerical simulation of such behaviour requires an accurate description of orthotropic material’s behaviour with damage. This paper describes 3D-Finite Element (FE) simulation results obtained using an elasto-plastic model coupled with an isotropic ductile damage, and implemented into ABAQUS/Explicit FE software. After a short presentation of the constitutive equations and their related numerical aspects, the validation of the model was carried out by simulating timber-steel hybrid beams. Good agreement was found between FE and experimental results, showing the good capability of the model to predict the ductile damage evolution in bending test of timber-steel hybrid structures.