Plastic Analysis of Steel Frame Structures using Computer Modeling

Plastic analysis is used in design of steel structures composed of various elements such as beams, frames, girders, arches etc. Here it is applied for determining the load-carrying capacity or limiting load at which the structure collapses. In this paper is presented a C# program, which computes the value of the load factor and determines whether the static distribution of the bending moment is safe, using methods of plastic analysis. The program has the capability of generating the possible mechanisms of collapse visually. Basic and combined mechanisms, generated by the program, could be viewed on screen. This is particularly important when choosing the optimal solution, because different mechanisms with the same load factors can be compared. Several examples, presented here, show how easy it is to create the model and perform the analysis. This is not only a simple analysis program, but also a program to enable the designer to create his models and to explore as many alternatives as he wishes.