Newer generation circular light sources shall radiate at even higher brightness, requiring a reduction of their emittance. Furthermore, high-energy photons are needed for research in materials science, biology, and chemistry. These requirements can be met by using superconducting longitudinal gradient bend magnets, foreseen for the upgrade of the Swiss light source. The design of this kind of magnets is challenging due to the need of a quasi-hyperbolic field profile with a peak around 6 T and providing a warm bore with an antechamber to extract synchrotron radiation. In this paper, we present an overview of the simulations of the electro-thermo-mechanical magnet behavior in operation and during a quench using multiphysics FEM tools.