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High-field REBCO magnets contain several coils with many turns. {For these magnets,} electro-thermal quench is an issue that magnet designers need to take into account. Thus, there is a need for fast and accurate software to numerically model the overall performance of full-scale magnets. High temperature superconductors can be modeled using different techniques for electro-magnetic (such as $H$-formulation and $A-V$ formulation) and thermal (finite element method) analysis. However, it takes a lot of time to model the electro-magnetic and electro-thermal behavior of superconductors simultaneously in a commercial software, especially for non-insulated or metal-insulated coils. We have developed a novel software programmed in C++, which performs coupled electro-magnetic and electro-thermal analysis using variational methods based on Minimum Electro-Magnetic Entropy Production (MEMEP) and Finite Difference, respectively. The developed software is applied to axi-symmetric fullscale magnets of more than 30 T field strength for transient design (thermal quench reliability), taking screening currents into account. We show that the magnets incorporating non-insulated coils {are more reiable against quench} than the metal insulated coils. Also, {realistic} cooling conditions at boundaries is essential for such simulations. The model developed can be used for a quick and complete electro-magnetic and electro-thermal analysis of superconducting high field magnets., Comment: Improved figures. Corrected text

High temperature REBCO superconducting tapes are very promising for high-field magnets. Under high magnetic fields there are high electro-mechanical forces, and thus concern for mechanical damage. Due to large screening currents and composite structure of the tape, the mechanical design of these magnets is not straightforward. In addition, many contemporary designs use insulated winding. In this work we develop a novel two-dimensional axisymmetric finite element tool programmed in MATLAB that assumes the displacement field within linear elastic range. The stack of pancakes and a large number of REBCO tape turns are approximated as an an-isotropic bulk hollow cylinder. Our results agree with uni-axial stress experiments in literature, validating the bulk approximation. Here, we study the following configuration. The current is first ramp up to below the critical current and we calculate the screening currents and the forces that they cause using the MEMEP model. As a case study, 32 T REBCO superconductor magnet, is taken and simulated numerically. We have done complete mechanical analysis of the magnet by including the axial and shear mechanical quantities for each pancake unlike previous work where only radial and circumferential quantities are focused. Effect on mechanical quantities without screening current is also calculated and compared. It is shown that including screening current induced field strongly affect the mechanical quantities, specially the shear stress. The latter might be the critical quantity for certain magnet configurations. Additionally, in order to overcome high stresses, a stiff over banding of different material is considered and numerically modelled which significantly reduces the mechanical stresses. The FE based model developed is efficient to calculate the mechanical behaviour of any general superconductor magnet and its devices.