AlfaBuild

REV RUS 3501-3501 ABE-1858-2021 57208300172 0000-0003-0031-7270 Peter the Great St. Petersburg Polytechnic University Kotliarskaia Irina Leonidovna iravassilek@mail.ru

St. Petersburg, Russian Federation

Ulanov Aleksandr Vadimovich O-6995-2019 6508103761 0000-0002-1196-8004 Peter the Great St. Petersburg Polytechnic University Vatin Nikolai Ivanovich vatin@mail.ru

Saint-Petersburg, Russian Federation

Assembly joints: A review of scientific literature, standards and terminology This review article evaluates the existing scientific literature, regulations, and terminology on assembly joints, their sealing, and material characteristics. The main objective is to systematize the fundamentals terms and definitions related to assembly joints and, based on the analysis, formulate arguments for classifying construction joints as "building products" or "building structures. Method. The review utilized a general scientific method of synthesizing, analyzing, and classifying information. Scopus and eLibrary scientific databases were used to identify and collect the most relevant studies. Results. An analysis of scientific research and regulatory documentation revealed a lack of empirical and theoretical data in the design of assembly joints for window unit junctions to wall structures. The reviewed publications emphasize the importance of the assembly joint for the performance of enclosing structures. Inconsistencies and contradictions in regulatory requirements (Russian State Standard GOST 30971-2012) for the design and selection of materials for assembly connections were noted. The standard's concept fails to take into account the characteristics of enclosing structures and climatic operating conditions, which contradicts scientific data. The required vapor permeability resistance values for the layers of the assembly joint lack sufficient justification. Conclusion. Based on the analysis conducted, an interpretation of the assembly unit as a set of functionally complementary layers (vapor barrier, thermal insulation and waterproofing) for insulating and sealing the gap between structures is proposed. The identified lack of scientific data and the lack of validity of regulatory documents indicate the need for further research to develop a methodology for selecting materials for assembly joint, taking into account the humidity regime and climate. 10.57728/ALF.35.1 60 Assembly Joint Airtightness Vapor Permeability Air Permeability Vapour Barrier Sealant Sealing Tape Moisture Adhesion Energy saving Terminology https://alfabuild.spbstu.ru/article/2025.35.1/ 3501.pdf

REV RUS 3502-3502 ABE-1858-2021 57208300172 0000-0003-0031-7270 Peter the Great St. Petersburg Polytechnic University Kotliarskaia Irina Leonidovna iravassilek@mail.ru

St. Petersburg, Russian Federation

Nosova Anastasiia Olegovna Uspenskaya Mayya Valerievna O-6995-2019 6508103761 0000-0002-1196-8004 Peter the Great St. Petersburg Polytechnic University Vatin Nikolai Ivanovich vatin@mail.ru

Saint-Petersburg, Russian Federation

Thermosensitive Coatings: A Review The object of the research is thermosensitive materials. Such materials are used in many sectors of the national economy to determine the temperature and measure the temperature fields of the surfaces of objects. Method. The Scopus and Elibrary databases, as well as the Technical Conditions (TC) of some thermosensitive products, were used to search and analyze literature on heat-sensitive materials. Results. The study of thermochromism and the development of thermochromic materials are of great interest due to the ability of these materials to measure the temperature of moving objects and objects located in hard-to-reach places, as well as submicron-sized elements. The article discusses the classification of thermochromic materials, their operating principle, chemical composition and types of temperature indicators, summarizes the experience and prospects for the use of temperature-sensitive materials based on a review of scientific literature. The trend and prospects for the development of temperature-indicating materials is to develop materials with certain established properties for each specific case. Targeted synthesis of temperature-sensitive pigments with the required set of technical characteristics is an urgent task. 10.57728/ALF.35.2 69 Thermosensitive materials Thermochromic materials Thermoindicating materials Smart materials Color reaction Colorimetric reaction Thermochromism Thermal pigments Luminophores Thermometry https://alfabuild.spbstu.ru/article/2025.35.2/ 3502.pdf

RAR RUS 3503-3503 Sliva Andrey Petrovich Saypulaev Gasan Ruslanovich saypulaevgr@mail.ru Saypulaev Musa Ruslanovich saypulaevmr@mail.ru 0000-0001-6122-8752 Moscow Power Engineering Institute Maslov Anton Nikolaevich maslovanton@list.ru

Moscow, Russian Federation

Potapov Maksim Andreevich Mathematical model of kinematics and requirements for drives of a precision positioning system The object of research is a four-axis precision positioning system used in a complex for electron beam welding of metal parts. The purpose of this work is to develop a mathematical model of the motion of the four-axis precision positioning system, find solutions to the direct and inverse problems of the positioning system kinematics, and estimate positioning errors due to the discreteness of the link drive movements. Method. A mathematical model of the positioning system motion is developed based on mechanics methods using direction cosine matrices linking the coordinate systems located on each moving link. The solution to the inverse problem is found analytically. Estimates for positioning errors are constructed based on the linearization of the kinematic equations. Results. A mathematical model of the kinematics of the four-axis precision positioning system is constructed. An analytical solution to the inverse problem of the positioning system kinematics is found, which can be used to transmit control signals to the drive drivers of the system links. Based on the obtained solution of the direct problem of the kinematics of the positioning system, upper estimates were made for the maximum errors in the positioning of welded parts for given dimensions of the parts and the errors of angular and linear drives due to the discreteness of their movements and backlash. ***ARTICLE IN PRESS*** 10.57728/ALF.35.3 69 CNC positioning system Four-axis manipulator Kinematics of the end-effector Positioning errors Motion geometry https://alfabuild.spbstu.ru/article/2025.35.3/ 3503.pdf

REV RUS 3504-3504 ABD-9922-2021 0000-0002-9330-2221 Peter the Great St.Petersburg Polytechnic University Iakovlev Nikita Artemovich nik_yakovlev@list.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

O-6995-2019 6508103761 0000-0002-1196-8004 Peter the Great St. Petersburg Polytechnic University Vatin Nikolai Ivanovich vatin@mail.ru

Saint-Petersburg, Russian Federation

Inter-module connections in modular construction: A review of terminology in literature and standards The object of research is inter-module connections in modular construction, which serve as critical elements ensuring load transfer, spatial rigidity, and structural integrity of modular buildings. The growing application of modular technologies has increased the importance of these connections, yet their classification and regulatory status remain inconsistent. There is an ambiguity between treating inter-module connections as construction products or as parts of building structures, which complicates design, certification, and quality control. Method. The research employed a systematic review of scientific publications, regulations and standards. The analysis was based on content examination of definitions, terminology, and requirements, followed by comparative analysis across the three groups of sources. Results. The study shows that scientific literature treats inter-module connections both as reproducible industrial products and as structural parts. Terminology in Russian standards is fragmented and inconsistent, allowing for multiple interpretations. In contrast, international standards more consistently define connections within the framework of construction products, with specific requirements for strength, stiffness, durability, fire safety, and documentation. It is proposed to consider inter-module connections as construction products, enabling quality control, traceability, and life-cycle management, while still acknowledging their structural role within modular buildings. 10.57728/ALF.35.4 69 Inter-module connections Modular construction Construction product Building structure Terminology Standards and regulations Off-site construction https://alfabuild.spbstu.ru/article/2025.35.4/ 3504.pdf