33407 2304-6295 8 47 2016 1-46

RAR RUS 7-16 Peter the Great St. Petersburg Polytechnic University Miftakhova Dinara dinara.miftakhova@gmail.com

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Dispersion method of heating system flushing 10.18720/CUBS.47.1 УДК 621.643.8; 620.197.2 buildings; energy efficiency; construction; heating; pipeline; internal corrosion; flushing; https://unistroy.spbstu.ru/article/2016.47.1/ 1_miftahova_47.pdf

RAR RUS 17-30 G-1611-2018 56352359500 0000-0002-5156-7352 Volgograd State Technical University Korniyenko Sergey Valeryevich svkorn2009@yandex.ru

Volgograd, Russian Federation

Increase of thermal insulation of external walls in box-shaped modules Results of scientific research of heat-shielding properties of modern designs of external walls in box-shaped modules are given in this article. On the basis of thermovision quality control of thermal insulation of external walls temperature anomalies in the edge zones of enclosing structures are revealed. Using results of thermal monitoring of the object, the most significant heterogeneous fragments of external wall are allocated. Deterioration in the thermal mode of designs is caused by considerable influence of the end-to-end heat-conducting inclusions of big extent accepted in the project. For the purpose of determination of a heat-shielding level mathematical modeling of heat transfer in external walls is executed. The most precisely additional heat-losses caused by influence of edge zones can be determined by temperature fields. The specified resistance to heat transfer (R-value) of the wall is in interval of admissible values according to Russian Norms (SP 50.13330.2012) and is close to economically reasonable resistance to heat transfer. However, extremely low value of heat transfer performance uniformity factor for external walls (0.49) is caused by the inefficient design solution of a heat-shielding. Enhancement of the constructive solution of panels of external walls application instead of edges of connectors reduces additional heatlosses and increases heat-shielding properties of designs. Higher value of heat transfer performance uniformity factor in the offered option (0.64) demonstrates increase of heat-shielding of external walls. Application the connector in a wall levels the temperature field and improves the thermal mode of a wall. 10.18720/CUBS.47.2 УДК 699.86 space block house prefabrication; enclosure structure; thermal insulation; heat monitoring; mathematic simulation; heat transmission; heat-losses; https://unistroy.spbstu.ru/article/2016.47.2/ 2_kornienko_47.pdf

RAR RUS 31-46 Peter the Great St. Petersburg Polytechnic University Ivanov Sergey serzikserzik@gmail.com

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Foschi’s method of strain calculation of the metal plate connectors compared to program complex APM Wood Metal plate connectors (MPC) are used for attaching together different parts of wooden structures, especially truss joints. Plates have rectangular form, they usually are made out of steel and sometimes can be covered by protection layer, for example, by zinc. Teeth of the plate can have different shape, length and mutual position. In order to connect wooden bars, MPC are pressed symmetrically on both sides of the structure, that is why attached elements should have the same cross-sectional width. For better adjustment of the elements, their ends are usually polished. Compression is carried out with special equipment and can take place both at the plants and at the construction site. The simplest algorithm of strain calculation of the joints with MPC can described, as follows: the construction is computed by usual methods of structural mechanics (FEM, flexibility method, force method) assuming all the nodes connected with plates are absolutely rigid. Then, using obtained internal forces and reference data about loads, leading to destruction or pulling MPC out of wood (laboratory tests are made by the manufacturer), appropriate plates are chosen. One of the program complexes using this pattern is APM Wood, the part of computer-aided design software APM Civil Engineering. The disadvantage of this algorithm is that it does not consider uneven distribution of forces on the various teeth of a plate and deformations appearing in the plates themselves, which leads to considerable error in found internal forces and inaccurate selection of plates. The model proposed by Foschi [1] is free of these disadvantages and can be used to estimate deformations and forces in MPS’s teeth. The paper gives an analysis of algorithm of calculation the nodes attached with metal plate connector and comparison to the program complex APM Wood. As an example, the problem of wooden bar fixed on both sides by MPC and under the influence of a force applied along the longitudinal axis is solved. As a result, it is concluded that consideration of plate and teeth flexibility in finite-element scheme is very essential for calculation accuracy, uneven stress distribution between the dowels has big influence on strain computation of the whole construction. 10.18720/CUBS.47.3 УДК 69.04 metal plate connectors; finite element method; Foschi's model; APM Wood; Maple; https://unistroy.spbstu.ru/article/2016.47.3/ 3_ivanov_47.pdf