PSI - Issue 36

Yaroslav Shved et al. / Procedia Structural Integrity 36 (2022) 10–16 Yaroslav Shved; Yaroslav Kovalchuk; Liudmyla Bodrova; et al. / Structural Integrity Procedia 00 (2021) 000 – 000

12

3

The problem of optimizing the material consumption of metal welded trusses has certain features, which include the need to consider the discrete assortments of rolled metal and the influence of topology on the efficiency of optimal structures. Good example is test on structural performance of light-frame truss by Wolfe (1996). Extensive opportunities for the development of universal calculation methods are given by the finite element method (FEM) based on deterministic approaches to modeling. It is included in the recommendations of the International Welding Institute and the norms of the German Association of Machine-Building Companies. Many papers in determining parameters of the stress-strain state (SSS) in the elements of welded trusses, taken as a basis for the described studies, were performed according to this methodological approach by Xiao (2004), Kovalchuk (2017), Kachka (2015). FEM involves the development of a finite-element mathematical model of the structure and its study by computer simulation experiment using known application software packages. The use of modern computer technology allows an engineer to perform such an experiment. Repeated run of the computer modeling experiment with different input parameters of the model makes it possible to identify the impact of these parameters on the strength and material consumption of welded trusses and optimize them. The study of the welded truss behavior under the effect of static loads was performed by a computer simulation experiment using ANSYS Workbench 14.5 application software package, which is algorithmically based on the finite element method. The static type of analysis of the rafter truss has been performed. Static calculation of the tr uss means the determining of the nodes’ displacements, the reactions of the supports, the forces in the rods, stresses, and deformations of the rods that occur in the loaded structure. The static analysis assumes that all loads and structural responses to loads are constant or change gradually over time. Some specific features of truss load simulation are described by Basara (2017). A solving mathematical model includes: • The geometric CAD model with the given load is a formalized physical model (Fig. 1a). • Finite element grid is a mathematical representation of a geometric CAD model, and it is a calculation of our model (Fig. 1b) • The accuracy of calculations is determined by the assumptions of the physical model and the density of the grid.

Fig. 1. Welded rafter truss with angle elements (a) CAD - geometric model; (b) CAE - finite element grid model.

Solving the problem under SSS includes the following basic steps: • Translate a geometric model from a CAD system. • Set the properties of materials and generating a grid. • Fix the model properties. • Apply a load and selecting solver parameters.