Impacts of temperature on the stress-strain state of aerial braces of arch systems

Introduction. In landmark buildings, floorings and roofs are performed as vault and arch systems. For accommodation of horizontal forces in the arches, aerial braces are used. Aerial braces of an arch system are a tie made of wrought iron with a cross-sectional area from 10 to 50 cm2. In the scientific and technical literature, information on aerial braces is extremely poor. Materials and methods. To assess the impacts of temperature deformations on the bearing strength of the aerial braces, a computational analysis was performed. On the basis of data on standard structural schemes of the landmark buildings, the characteristic length of aerial braces was taken into account. Averaged climatic data calculated on the basis of weather observations for the period 1988–2017 for 13 climatic regions of Russia were analysed. Since the data on the temperature of the closure of the distance piece system are irrevocably missing, two variants of the outdoor temperature were considered for the installation of the aerial braces: zero and the maximum summer temperature. Results. Calculations were carried out and the strain arising in the aerial braces at the corresponding temperature elongation values obtained under recognition of the different temperatures of arch system closure was determined. Totally 78 temperature graphs were obtained and analysed for different climate areas, with different closure temperatures of arched systems. Conclusions. It was found out that, for the assessment of the impacts of temperature deformation on the bearing capacity of aerial braces, the actual temperature of the arch system closure is decisive. The safety factor of the bearing strength of aerial braces of arch systems for most climatic zones exceeds 50 % and can reach 92 %. At the same time, for two areas with significant negative temperatures in the winter period, the utilization ratio of aerial braces can reach 0.6–0.63. The maximum temperature elongation of aerial braces with a length of 6 m does not exceed 3 mm in case of mounting at the maximum summer temperature and 2 mm at the zero point.