Torsional-Flexural Critical Force for Various Boundary Conditions

摘要

The system of governing differential equations of stability of members with the rigid open cross-sections was developed by Vlasov [1] in 1940. Gol'denvejzer [2] published in 1941 solution of this system by an approximate method. He proposed formula for torsional-flexural critical force N_(cr).tf calculation which is modified and used in EN 1999-1-1 [3] (1.19). By introducing factor a_(zw) he take into account any combination of boundary conditions (BCs).The purpose of this paper is to verify this formula and explore the possibility to improve the factor a_(zw). In the large parametrical study the authors investigated a lot of different shape of cross-sections, all 100 theoretical possible combinations of BCs and various member lengths. All results are evaluated regarding the reference results by finite element method (FEM).