Search

Energy-efficient, adaptive, affordable and durable curtain wall systems have always attracted great interest among the scientific and technical communities. In this regard, the purpose of this work was to conduct a comprehensive review of the issues related to energy-efficient adaptive dynamic facades, taking into account their operating loads, revealing the diversity of the studies conducted in this area. The review of the literature was carried out in three stages. For all stages, the review period was 2001–2024. In the first stage, a review of traditional curtain facade systems was conducted, which emphasized the relevance of this area, identifying a total of 4338 sources. In the second stage, a review of specific issues, such as adaptive dynamic facade systems, yielded 2838 sources, from which the 87 most suitable sources were selected. In the third stage, a review focusing on the issue of operating loads yielded 741 works, from which 43 suitable sources were selected. At the same time, pie charts reflecting the most active international scientific journals were compiled for each area. The conducted review of energy-efficient adaptive dynamic building facades, taking into account their operating loads, could provide significant assistance in further research on the specified issues. As researchers mainly focus on environmental friendliness and cost-effectiveness, they often neglect issues such as the systems' resistance to operating loads, which represents a serious deficiency. In this regard, this review identified a gap in the research on the development of energy-efficient facades with an air layer; on this basis, the further development of adaptive facade systems is required. The review of the selected studies also showed that issues related to energy efficiency and sustainability, taking into account operational loads, have not been addressed in combination; rather, they have only been addressed individually. At the same time, this review shows that the proposed development of an adaptive system of external fencing could be relevant, both nationally and internationally, depending on the natural and climatic conditions of the territory for which the buildings are designed. [ABSTRACT FROM AUTHOR]

This article presents the results of thermophysical studies conducted in the cold period by non-destructive testing of translucent exterior building envelopes for heat protection and illumination of the room with natural light. As an object of study was chosen 3-room apartment on the fifth floor of the 17-storey residential complex “Sport Towers”, located in Astana, where the survey was conducted in the daytime. The window openings of the respective rooms were selected as translucent exterior envelope. As a result of the survey it was found that the internal temperature of the living rooms has a deviation of 3.5% from the optimal norm on the parameters of microclimate of the premises, which leads to a violation of the norm and overconsumption of heat energy for heating due to inadequate thermal protection of translucent exterior envelopes. At humidity 48.1% and internal temperature of the room 19.3 °C that the dew point was 8.1 °C. The value of the surface temperature including in the zone of adjoining to opaque elements of the considered structures showed deviation from -16.3°C to 8.0°C, which exceeds the dew point temperature in some cases in 3 times. The total area that does not meet the norm of the examined fragments of translucent exterior envelopes was from 5.9% to 100%. It is noted that the above deviations in heat protection of buildings can lead to the appearance of mold on the inner surface of the envelopes. The qualitative and quantitative indicators obtained as a result of thermophysical studies are the basis for the design of translucent parts of the exterior envelope when they work together with the blind wall part of the façade systems and in the future will be taken into account by designers in the development of new energy-saving exterior envelope structures, which are planned to be implemented throughout the Republic of Kazakhstan, taking into account climatic features.

In the study a full-scale thermovisional survey was carried out in the cold period of time of a multi-apartment residential building located in the Northern part of the Republic of Kazakhstan. The result of the survey showed the presence of significant problems on heat protection, where according to the analysis of thermograms of external wall envelopes it was revealed that almost all living rooms have envelopes with a negative value of heat protection, which does not meet existing standards. The analysis of thermograms of all rooms showed the existing problems on thermal stability of external wall envelopes, as the temperature difference between the inner surface of the external envelope and the internal air temperature ranged from 5.5 °C to 19.7 °C, where the difference reached 49 times in some places, depending on the living room. Analysis of thermograms of window openings also showed a lot of deviations. Thus, thermograms of window apertures showed deviations from sanitary-hygienic norms on dew point value from 12°C to 26.2°C depending on the living room. The revealed deviations on thermal protection of external envelopes are the main sources of heat energy loss and indicate the presence of problems on thermal stability of external envelopes in the cold period, which require special attention. In this regard, the obtained results of this study will be further taken into account in the development of new and optimization of existing wall envelope structures, taking into account the climatic features of the Republic of Kazakhstan.

This paper reports an analysis of the frequencies and shapes of oscillations of the tank with a volume of 3000 m³ with a winding of highstrength steel wire with a diameter of 3 mm, 4 mm, and 5 mm, applied in increments of 1:3. In addition, for the tension force of the turn in the range from 0.2 to 0.8 of the yield strength of the wire material. The study was carried out on the basis of a finite-element method in the ANSYS software package for a three-dimensional geometric model of the structure. At the same time, the software took into consideration the height-uneven width of the cylindrical wall taking into account the height of the filling to the maximum height and the tension forces of the winding. It has been established that a change in the diameter of the winding wire does not lead to a significant change in the spectrum for the first ten significant frequencies. And an increase in the tension force of the wire in the winding leads to a decrease in the magnitude of oscillation frequencies. The exception is the sixth frequency. Its values are equal to one-tenth of a Hz for all estimated cases of the force of tension of the turn in the range from 0.2 to 0.8 of the yield strength of the wire material. The oscillation shapes of the tank reinforced by the winding have been determined. The change in the tension force of the wire in the winding does not change the number of waves at the circumferential coordinate at the free edge of the structure. We studied the loss of stability of the tank wall under distributed internal pressure. A comparative analysis of the sixth oscillation shape and the shape of stability loss reveals that they have the same number of waves at the circumferential coordinate. The results reported here could make it possible to effectively use the pre-stress in order to detune the tank from the resonant frequency when operating in seismically hazardous areas [ABSTRACT FROM AUTHOR]

This paper conducted an experimental study of reduced models of a main gas pipeline for avalanche damage considering operational conditions. Two options were considered as a method of avalanche damage prevention: single steel rings at the crack edges and steel winding with a winding pitch of 0.25 m. For the tension force, 5% of the steel wire breaking force was taken, which was equal to 1 mm. The ambient environment was simulated by a climatic chamber, where two options of temperature loads were considered: +20 °C and -10 °C. It was found that reinforcement with single rings of pipeline models under conditions of positive (+20 °C) and negative (-10 °C) temperatures showed that the crack opening width in the ring direction decreased 1.63 times and 1.9 times, accordingly. The crack length (longitudinal direction) decreased 2.18 times and 2.45 times, accordingly. The reinforcement of the pipeline models with prestressed wire winding on the crack propagation under conditions of positive (+20 °C) and negative (-10 °C) temperatures showed that the width of the crack opening in the ring direction decreased 1.5 times and 1.46 times, accordingly. The crack length (longitudinal direction) decreased 1.4 times and 1.44 times accordingly, which is a positive moment in addressing the issue of the localisation and stoppage of a crack fracture in main gas pipelines. Simultaneously, the analysis of the prestressed pipelines model test results on crack fracture propagation showed that single rings are more effective, which decreased the crack opening width by 1.1 times and the crack length up to 1.5. Therefore, the experimental results obtained positively complement the available methods of crack localisation in main gas pipelines, which can be used by engineers and research communities when designing or reinforcing existing operating main steel gas pipelines.