Bulletin of Prydniprovs'ka State Academy of Civil Engeneering and Architecture

18-26

Authors: Timoshenko E. А., Cand. Sc. (Tech.); Savytskyi M. V., Dr. Sc. (Tech.), Prof.

Purpose. Person is exposed to adverse factors, not only in the workplace, but also being in residential buildings. Modern person spends the main time indoors. Comfortable existence and human health is largely dependent on how internal living environment is environmentally safe and air quality control of dwelling is determinative in environmental safety of human’s dwellings. It is necessary to analyze the range of external and internal factors influencing on the ecological safety of dwelling and evaluate them using the systematization of parameters and criteria proposed by various researchers. Methodology. On solving the problem of ecological safety of the dwelling focused specialists in various fields of science (toxicologists, hygienists, ecologists, architects, engineers, designers, and so on) it’s necessary to join their knowledge and investigation with a purpose of one creation of one concept of the environmental safety of residential buildings. Findings. The analysis and characteristics of the main factorsare carried out influencing the environmental safety of the premises of residential buildings, with an assessment of their impact on human health. Bioclimatic criteria for assessing the environmental factors are proposed affecting the ecological safety of homes. The chemical and physical sources of air pollution in residential buildingsare analyzed. Priority ecological and hygienic parameters are identified determining the environmental safety of the living environment. Practical value. The result of this work to analyze the factors affecting the quality of the living environment inside buildings, can be used in the development of a unified method for integrated assessment of ecological safety of modern residential houses of harmonious construction materials and also in a creation of one concept of the environmental safety of residential buildings.

35-44

Authors: Sakharov V. O., Ass. Prof., PhD.

Problem statement . Modern analysis of the dynamic conduct of constructions and structures relies on numerical modeling. The difficulty and complexity of dynamic problem solving encourages model simplification and the use of more advanced numerical modeling algorithms. Many buildings are characterized by the presence of repetitive structural elements (e.g. typical floors). This feature can be used to improve the efficiency of numerical methods by reducing the size of the equation system while meeting the requirements of direct integration methods. Purpose. The paper presents the theory and practical implementation of an improved technique for solving high-order dynamic problems using explicit methods and the help of spectral super-elements for selected substructures. This approach can reduce the order of the algebraic system and conduct dynamic (and thus - seismic) analysis of buildings and structures while taking into account nonlinear deformations of the soil foundation. Analysis of recent research. Modern methods and computer tools allow analysis of dynamic problems while taking into account nonlinear deformations. Such problems have systems of equations with millions of variables and require significant computational resources and time. To reduce the order of the system, commonly used approaches include dynamic reduction methods (e.g. Guyan reduction) or methods relying on reduced-order substructural models. In particular, a paper by Ray W. Clough suggests that the dynamic properties of FE have a higher level of approximation than mechanical properties. For buildings and structures, it is usually most convenient to use substructural models relying on eigenform-based motion representation, as proposed by Craig Jr. R.R., Bampton M. and other authors. However, the proposed options lead to a non-diagonal mass matrix and limit the effective use of explicit integration schemes. Results. The paper describes a method of use of superelement technology of solving tasks of dynamic for investigation of the interaction of buildings with the soil base. On the base Craig-Bempton approach, variant of getting reduction matrix for developed superelement of spectral is offered for taken subconstruction which is providing preservation diagonal mass matrix and allows the use of efficient explicit integration methods. The results of the study of a building interaction with a non-linear soil base under active seismic load are shown. Use an actual construction as an example, it is shown that the use of spectral superelements reduced of the order of the equation system by a factor of more than 2.8 while maintaining the required accuracy of the calculation. Conclusion. The described method of solving dynamic problems, using the proposed spectral superelements, significantly reduces the order of the equation system while still allowing the use of explicit numerical integration schemes. This allows the more efficient dynamic analysis of the behavior of the “soil base - foundation - building” system.

51-59

Authors: Makarov A. V.

Raising of problem. In the Ukrainian mining and metallurgical complex, chemical and energy industries exploit the wide span gantry for loading and unloading of bulk materials. All the wide span gantry are installed outdoors and, in addition to the atmospheric precipitation, perceive more aggressive technological impact on primary production (water vapor cooling towers, towers quenching coking plant, lime, a pair of air from swelling slag et al.). Working amplitude of oscillations bearing structures of the wide span gantry loader when driving trucks with weighing hundreds of tons lead to fatigue damage - hence the high cost of time and money to remove them. In the literature by calculations and operation of wide span gantry it isn’t consider the questions of research of dynamic loads with technological operations, the accurate definition of dynamic calculations of bearing metal and the possibility of the theoretical prediction their condition, the amplitude decay of oscillations and accelerate production of works with implementation of full-scale study. It’s doing the expert survey with the frequency at least once every 2 years after the end of their service life time of the wide span gantry to determine further technical condition of the crane [9]. The problems in the assessment of aging equipment residual bind with the lack of efficacy of traditional methods of indestructible control. Purpose. On the basis of theoretical research, it will connect the frequency and the shape of the natural oscillations of the spatial model of steel structures wide span gantry with basic versions for possible damage. Conclusion. On the basis of creating a set of emergency wide span gantry you can make the atlas of damage of steel structures. It will allow to do the rapid analysis with changing of the oscillation frequency one of the form, following indication site and possible cause of damage to the main load-bearing steel structures.