CONCERNING DESIGN CALCULATIONS OF BUILDING STRUCTURES

he work is devoted to the analysis of discrepanciesbetween linear and non-linear calculation of buildingstructures that deform under the influence of load. Ithighlights the existence of two fundamentally differentprocedures inherent in design calculations, namely:(i) static or dynamic analysis of the behavior of themechanical system, resulting in the parameters of thesystem's stress-strain state and (ii) assessment of theУДК 624.046:5Doi: https://doi.org/10.33644/2313-6679-3-2024-3ПЕРЕЛЬМУТЕР А.В.Доктор техн. наук, головнийнауковий співробітник, Науково-виробниче товариство «SCADSoft»,Київ, Українаe-mail: [email protected]тел.: +38 (050) 382-16-25ОRCID: 0000-0001-9537-2728ISSN 2313????6669 ????SCIENCE & CONSTRUCTION???? ????НАУКА ТА БУДIВНИЦТВО16 ???? 3(41)’2024possible resistance of the system elements and thestructure as a whole.It is shown that when using linear analysis, theseprocedures set the content of independent calculationstages. In nonlinear analysis, they are combined andmutually influence each other.Attention is drawn to the features unique to thenonlinear analysis, such as:– the impossibility of using rod finite elementswithout breaking the length of the rod intoelementary sections;– the occurrence of tensile-compression stress duringbending, as a result of asymmetric developmentof plastic deformations along the cross-sectionheight;– the possibility of realizing extreme responses ofthe system at intermediate (not extreme) values ofload intensity;– the dependence of physically nonlinear analysisresults on the sequence of load applications;– the possibility of geometric nonlinearity toinfluence the behavior of systems under load insuch a way that the self-reinforcing effect of thestructure occurs.The problem of determining the ultimate state ofthe system, which corresponds to the global assessmentof the load-bearing capacity, is considered. Given thecomputational difficulties of numerical analysis whenthe system approaches a mechanism state, it is proposedto accept the state in which the system's resistancedecreases by several orders of magnitude compared tothe beginning of the loading as the limit state.Attention is also drawn to cases where the ultimatestate is determined by the level of deformation of thesystem.