MANUFACTURABILITY FACTORS OF PREFAB-CONSTRUCTION FROM STEEL THIN-WALLED COLDFORMED ELEMENTS

The article systematizes the factors and their influence on the manufacturability of prefab structures from steel thin-walled cold-formed elements. It is known that LSTS are modern building structures that are efficient in terms of material consumption. Despite this, many of them, due to labor costs during manufacture and installation, are characterized by increased cost, and cannot always be considered technologically advanced. Since the study of manufacturability factors opens up new opportunities for their effective use in the design of objects from LSTS, the author classifies them into two groups: factors determined by the level of development of means of production; factors determined by the properties of objects of labor. As a result of a brief review of the development of manufacturability ideas, a number of provisions have been formulated regarding a clear distinction between factors and indicators of the manufacturability of objects and structures. Based on the performed comparative analysis, two types of equipment for the production of LSTS were identified: type I – for low-rise frame-panel construction; type ІІ – for all options for the use of LSTS in construction, incl. for multistorey and commercial construction. The efficiency of modern LSTS production depends on the following parameters: design time, time for transferring details to equipment, speed of the production process, production changeover time. It is noted that the speed of profiling is not a key parameter for the production of LSTS. More important is the issue of equipment readjustment to other profile sizes, which can cause significantly more time than the rolling process itself, and, accordingly, reduces the manufacturability of LSTS. A significant characteristic of a modern line, which ensures the manufacturability of the production of LSTS, is the presence of a minimum set of presses to perform the necessary operations on the produced profile (bulging, profile bending, cutout in the fabric, holes for screws, crimping of the ends of the profile), which reduce labor intensity and speed up the subsequent assembly of structures from steel thin-walled cold-formed elements. It seems promising to design LSTS only from C-profiles of the same section and thickness due to an increase in their manufacturability by eliminating such factors as changing equipment to a profile of a different type, sorting elements when assembling a bundle of panels, transporting structures from the factory when using compact lines directly on the construction site. It is substantiated that the use of lines of the first type is effective for the implementation of this approach.