The research results of the effect of concentration of injected mineral filler on change in adhesion strength of acrylic adhesive composition to the metal substrate are given in the article. The adhesive composition was prepared based on pre-compounded reaction system: the stabilized monomer – methyl methacrylate and polymer modifier – sterol copolymer with methyl methacrylate with followed filling and polymerization in the presence of a redox system. It is shown that the mobilization to resource preservation of the adhesive contact at the allowable amount of the filler and the thickness of the adhesive layer is due to the overall contribution of the dispersed phase in the change of the structure and macrophysical properties. Experimental data confirm the obtained dependencies: the adhesive strength of the adhesive from the contact area to steel wire; density, glass transition temperature and the calculated value of the Simcha-Boyer constant of block samples from the amount of the filler; character of reducing dynamic shear modulus of the filled composition during heating. It is suggested that the decrease in density in a volume of polymer phase of filled system provides a slight decrease in adhesion strength of acrylic adhesive to the substrate.

One of the main tasks, which is solved at the design stage of the reinforced concrete element, is the analysis of the stress-strain state, as well as the determination of the service life. The article is devoted to modeling of nonlinear creep of reinforced concrete structural elements taking into account damages and return of the creep. The high priority of the research topic is substantiated, the purpose and objectives are formulated. A combination of a plastic model with fracture mechanics is proposed to simulate the behavior of concrete in accordance with its characteristics, including not only stress and deformation, but also the degradation of its stiffness. The resulting equations of state correspond to the law reverse deformations. The finite element method is used to solve the boundary value problem. For the sake of numerical modeling of thin-walled structures, the use of special shell elements is proposed. The mathematical formulation of the problem of creep of reinforced concrete structural elements taking into account anisotropy of material properties and creep deformations and return of the creep is presented. Creep problems of thin-walled structural elements were solved with the help of developed software. Analyzed the deformation of reinforced concrete panel of cylinder. The analysis of the results allows us to judge the effectiveness of the proposed model as a whole. The equation of state reflects the anisotropy of the material properties and takes into account the damage, which allows for a reliable assessment of the strength, stiffness and durability of reinforced concrete structures. Conclusions about the adequacy of the analysis of reliability and durability of reinforced concrete structures using the proposed model.

*Кафедра теоретичної та будівельної механіки Харківський національний університет міського господарства ім. О.М.Бекетова вул. Революції,12, м. Харків, Украина, 61002 Наведено результати дослідження залежності інтегральних квадратичних величин абсолютного прискорення й відносного зміщення силосу від конструктивних характеристик корпусу, колон та параметрів сейсмічного впливу. Розв'язана задача мінімізації інтегрального квадратичного відносного зміщення силосу вибором коефіцієнта демпфірування. Отримано вирази для оптимального значення коефіцієнта демпфірування і інтегрального квадратичного критерію як функції граничного значення абсолютного прискорення Ключові слова: коливання, корпус силосу, сейсмічні впливи, зсув, прискорення, демпфірування Приведены результаты исследования зависимости интегральных квадратических величин абсолютного ускорения и относительного смещения корпуса от конструктивных характеристик корпуса, колонн и параметров сейсмического воздействия. Решена задача минимизации интегрального квадратического относительного смещения силоса выбором коэффициента демпфирования. Получены выражения для оптимального значения коэффициента демпфирования и интегрального квадратического критерия как функции предельного значения абсолютного ускорения Ключевые слова: колебания, корпус силоса, сейсмические воздействия, смещение, ускорение, демпфирование

No abstract

One of the main tasks that is solved at the design stage of a reinforced concrete structure and its elements is the analysis of the stress-strain state, as well as the determination of the service life of the structure. The article is devoted to modeling the nonlinear creep of reinforced concrete structural elements taking into account damage and shrinkage of concrete. The high priority of the research topic is substantiated, the goals and objectives of the research are formulated. A combination of a plastic model with fracture mechanics is proposed to simulate the behavior of concrete in accordance with its characteristics, including not only stress and deformation, but also the change in its characteristics over time. The obtained equations of state correspond to the incremental creep law, taking into account the damage and shrinkage. The finite element method is used to solve a boundary value problem. For the purpose of numerical modeling of thin-walled structures, it is proposed to use special shell elements. The mathematical formulation of the problem of creep of reinforced concrete structural elements taking into account creep deformations and volumetric deformations of concrete shrinkage is presented. The problems of creep of thin-walled structural elements were solved using the developed proprietary software. Deformations of a reinforced concrete cylindrical panel are analyzed. Analysis of the results allows us to judge the effectiveness of the proposed model as a whole. The equation of state reflects the properties of the material and takes into account damage, allows you to reliably assess the strength, rigidity and durability of thin-walled reinforced concrete structures. Conclusions are presented regarding the adequacy of the analysis of the reliability and durability of reinforced concrete structures using the proposed model.