Analysis of the stress-strain state of the spanning trihedral truss under linear loads

Abstract

Introduction. The structures of trihedral trusses for roofs and overlaps of industrial and public buildings, various combined systems and as trestle structures of linear objects in different building regions are considered. The work presents a patented design of the spatial three-sided truss with the continuous chords of the closed compound cross-section made of rolled sections with the seamless joints. The pentagonal composite cross-section of the girders is composed of rolled channels and angles. The purpose of numerical studied is the estimation of the stress-strain state (SSS) of a span trihedral truss with placement of a profiled deck covering directly along its upper continuous chords, systematization of the received information for substantiation of element composition of structures as well as the formation of a verification base of numerical experiments for further development of complex scientific studies. Materials and methods. Numerical research is based on a special-rod model of a spanning trihedral truss. The adopted method takes into account the application of linear static loads with zero variability of values, which simulates the location of the enclosing structure of the corrugated sheeting along the upper chords. The adaptation of the single loads method is oriented to the evaluation of the reaction of the rod system in order to analyze and compare data with the results of the following tasks within the framework of the complex research. Results. The results characterizing the deflected mode of the trihedral truss model as a distribution of efforts in the rods and vertical displacements of the joints have been obtained. They have been analyzed, their dependencies have been found and the regularities have been revealed. Conclusions. The analysis of the obtained results shows that the accepted computational model of a trihedral truss adequately reflects its SSS. Practical application of numerical results consists in the possibility of their use for substantiation of element structure at designing a construction of a three-sided truss. The results obtained are included in the verification data base for further numerical studies of actual operation of span trihedral trusses.