AbstractFatigue damage to existing steel bridges occurred due to the large increases in traffic loads and the notch sharpness in the details of orthotropic steel roadway slabs. The development of the orthotropic‐composite‐slab (OC‐slab) provides an alternative durable and lightweight composite construction. As part of the AIF‐FOSTA research project P1265 [1], the orthotropic‐composite‐slab for road bridges is currently being investigated at the Technische Universität Dresden. The project aims to develop fundamentals for the design of OC‐slabs with dowel strips. The investigations create important foundations for the establishment of the innovative construction method as an economical and durable alternative. The papers [2] and [3] give an overview of the construction and the load bearing behavior of the OC‐Slab, the paper [4] details about the experimental test program. This paper describes the numerical investigations carried out. They complement the experimental tests and provide additional knowledge about the load‐bearing and fatigue behavior of the OC‐slabs with dowel strips. The focus is on the presentation of the numerical simulation of the beam test and the determination of the ultimate and fatigue strength of the structure.