In this thesis a FE-simulation model of a cylindric laboratory furnace lined with refractory materials was developed using a 3D-unit-cell approach. With this model thermomechanical simulations of a temperature cycle similar to that of a steel ladle in secondary metallurgy were carried out using the software Abaqus [1]. Under the assumption of elastic material behaviour in the working lining (alumina-spinel bricks) and plastic behaviour in the steel shell the element size was varied to determine an optimum element size under consideration of the numerical costs. Furthermore, the initial expansion allowance of the vertical side joint was varied to investigate its influence on the maximum occurring stresses and the opening of the joint. To identify the influences of creep, tensile and shear failure in the working lining simulations were performed using the material constitutive models power-law-creep, concrete damaged plasticity and Drucker-Prager which are available in Abaqus [1]. The results were compared regarding the stress-strain behaviour and the opening of the joints during the heating cycle. Thereby it could be shown among other things that the creep failure had the biggest influence on the opening of the joints between the alumina-spinel bricks. The investigations with the material constitutive models included in Abaqus [1] provide the opportunity to predict and compare the phenomena of creep, tensile and shear failure in the refractory lining with efficient numerical costs. However, a drawback of this method is that the influence of the different failure mechanisms on each other cannot be depicted. Nevertheless, the simulation results give an overview of the different loads that can be expected in the lining of the laboratory furnace and provide a basis for comparison with measurement results which are generated after the completion of the laboratory furnace.