PT Journal AU Ondris, L TI Fast Three-phase Mass Minimization of Truss and Shell Structures with Stress and Stiffness Constraints SO Acta Mechanica Slovaca PY 2023 BP 16 EP 25 VL 27 IS 1 DI 10.21496/ams.2023.013 DE steel structures; mass minimization; FE analysis; truss elements; shell elements; fully stressed design; stress constraint; stiffness constraint AB The paper describes a new iterative optimization procedure and its simple to use computer implementation, allowing to minimize the mass of truss and shell structures under static load while satisfying the stress and stiffness constraints and keeping the mesh topology of the structure. The procedure first fulfils the stress constraint, then the stiffness constraint. Finally, the continuously found design variables can be replaced by discrete values from user's catalogue. Seven optimized structures are described, and results are discussed in detail. Compared to other optimization procedures, the described technique is an order of magnitude faster and suitable for everyday use in design practice of even large structures. ER