Abstract:Occurrence of extreme man-made impacts on buildings and structures has become frequent lately as a consequence of condensed explosives or explosive combustion of gas-vapor or air-fuel mixtures. Such accidents involve large human and economic losses, and their prevention methods are not always effective and reasonable. The given research aims at studying the way of enhancing explosion safety of building structures by means of yielding supports. The paper presents results of numerical studies (finite element, 3D nonlinear) of strength and deformability of yielding supports in the shape of annular tubes under static and short-term dynamic loading. The degree of influence of yielding supports was assessed taking into account three peculiar stages of deformation: elastic; elasto-plastic; elasto-plastic with hardening. The methodology for numerical studies performance was described. It was established that rigidity of yielding supports influences significantly their stress-strain state. The research determined that with increase of deformable elements rigidity dependency between load and deformation of yielding supports in elastic and plastic stages have linear character. Significant reduction of dynamic response and increase of deformation time of yielding supports was observed by increasing the plastic component. Therefore it allows assuming on possibility of their application as supporting units in reinforced concrete constructions.Keywords: yielding supports, strength, deformability, numerical simulation, finite element method, explicit dynamic, nonlinear effects ЧИСЛЕННОЕ МОДЕЛИРОВАНИЕ ПОДАТЛИВЫХ ОПОР В ВИДЕ ТРУБ КОЛЬЦЕВОГО СЕЧЕНИЯ ПРИ СТАТИЧЕСКОМ И КРАТКОВРЕМЕННОМ ДИНАМИЧЕСКОМ НАГРУЖЕНИИ О.Г. Кумпяк, Н.В. МещеуловТомский государственный архитектурно-строительный университет, г. Томск, РОССИЯ АННОТАЦИЯ: В последнее время участились случаи экстремальных техногенных воздействий на здания и сооружения, например, вследствие взрыва конденсированных взрывчатых веществ либо взрывного горения газо-, паро-или пылевоздушных смесей. Такие события могут повлечь большие человеческие и экономические потери, а методы их предотвращения или снижения последствий не всегда эффективны и рациональны. Целью данной работы является изучение способа повышения взрывобезопасности строительных конструкций за счет применения податливых опор. Представлены результаты численных (конечноэлементных, в трехмерной нелинейной постановках) исследований прочности и деформативности податливых опор в виде труб кольцевого сечения при статическом и кратковременном динамическом нагружении. Произведена оценка степени влияния податливых опор, имеющих три характерные стадии деформирования: упругая; упруго-пластическая; упруго-пластическая с отвердением. Приведено описание методики численных исследований и ее программной реализации. Установлено, что при увеличении жесткости сминаемых вставок зависимость между нагрузкой и деформированием опоры в упругой и пластической стадиях имеет линейных характер. Выявлено также значительное снижение динамической ре...

Abstract. Extreme events, both natural and man-made, have become more frequent. Explosions, falling or impact of bodies influence buildings and structures causing occurrence of high intensity inertia forces. Due to dynamic nature of the mentioned impacts they are to be considered in design calculations. The paper studies behavior of oblique sections of reinforced concrete (RC) beams under transverse dynamic loading; it describes the potential of using yielding supports, presented as inserted elements with ring cross-section. Experimental study included tests of 24 RC beams under shortterm dynamic impact of falling weight (265 kg). The behavior of RC beams was analyzed by measuring deformation of reinforcement and concrete, the value of supports reaction and impulse acting on a structure. The paper considers separate and joint effect of yielding supports and longitudinal compression on strength and deformability of RC beams. Longitudinal compressive force and yielding supports are proved to influence significantly the stress-strain state of oblique sections of RC beams under dynamic loading. Time of deformation is significantly prolonged in case of extended plastic component in yielding supports.

Dynamic impacts that became frequent lately cause large human and economic losses, and their prevention methods are not always effective and reasonable. The given research aims at studying the way of enhancing explosion safety of building structures by means of yielding supports. The paper presents results of numerical studies of strength and deformation property of yielding supports in the shape of annular tubes under static and short-term dynamic loading. The degree of influence of yielding supports was assessed taking into account three peculiar stages of deformation: elastic; elasto-plastic; and elasto-plastic with hardening. The methodology for numerical studies performance was described using finite element analysis with program software Ansys Mechanical v17.2. It was established that rigidity of yielding supports influences significantly their stress-strain state. The research determined that with the increase in deformable elements rigidity dependence between load and deformation of the support in elastic and plastic stages have linear character. Significant reduction of the dynamic response and increase in deformation time of yielding supports were observed due to increasing the plastic component. Therefore, it allows assuming on possibility of their application as supporting units in RC beams.

This research is aimed at studying the method for improving blast resistance of buildings and structures by using yielding supports. The paper reports the data on dynamic analysis of reinforced concrete elements subjected to compression and bending on yielding supports under the condition of elasto-plastic stress-strain state performed in ANSYS software package. Algorithms and techniques for dynamic amplification factor calculation for reinforced concrete elements subjected to compression and bending are presented. The paper provides load diagrams of dynamic amplification factors with the account of yielding capacity of supports for subsequent dynamic analysis of structures for equivalent static load.

Increasing energy efficiency and reducing heat loss in buildings are the main challenges of the modern construction sector. For this reason, it is recommended to design buildings using modern energy-saving materials and technologies. When using multilayer walls in housing construction, the problem of thermal bridges arises. Therefore, you need to understand how the thermal behavior of the enclosing structure changes when thermal engineering inhomogeneities are included in it. The aim of this work is to study the effect of heat-conducting inclusions located in external enclosing structures on the change in the values of temperature and heat flux density. The paper considers the importance of increasing the energy efficiency of outdoor fences. A numerical study of the heat transfer process for corner fragments of enclosing structures used in housing construction using the VELOX technology has been carried out. The influence of the design features of the considered corner fragments on the characteristics of temperature fields is shown. Mathematical modeling of spatial heat transfer in the corner fragment of the outer enclosure is carried out using a nonlinear system of differential equations of heat conduction with specified boundary conditions using the finite element method. The problem was solved using the ANSYS software package. The influence of metal and fiberglass connectors on the change in the fields of temperature and heat flux density in the enclosing structure has been investigated. The change in the thermal state is considered both in the thickness of the outer wall and along the inner surface of the fence from the corner area and along the smooth surface of the wall. Analysis of the calculations showed that the maximum disturbance is introduced by the connector made of metal, and the minimum — from fiberglass. The presence of highly heat-conducting inclusions in the thickness of the structure leads to a distortion of the density field of the heat flux of the fence.