PSI - Issue 36

Yaroslav Shved et al. / Procedia Structural Integrity 36 (2022) 10–16 Yaroslav Shved; Yaroslav Kovalchuk; Liudmyla Bodrova; et al. / Structural Integrity Procedia 00 (2021) 000 – 000

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1. Introduction The relevance of the study is due to the fact that currently the high cost of metal creates the preconditions for minimizing material costs while maintaining the strength of the truss. Trends in modern construction are characterized by architectural expressiveness, originality, scale, and optimal use of raw materials and structures. This approach can be implemented through the use of welded grid structures, trusses in particular. In this regard, the creation of structures that are competitive to those imported to Ukraine is an urgent task associated with achieving the greatest savings in metal, reducing the complexity of manufacturing, and reducing installation time while maintaining the design performance. Widespread use of metal welded trusses in construction is a consequence of a set of positive characteristics in these structures. To ensure their competitiveness in the construction products market, it is necessary to reduce their cost by optimizing the design at high strength indicators. The most common optimization criterion is the weight of the structure. Since the cost of the material is approximately 70% of the cost of the truss, the application of this criterion is decisive. Modern methods of computer simulation experiments make it possible to perform complex calculations to determine the design parameters of the truss at the optimal ratio of their strength and material consumption. The aim of the paper is to identify the patterns of deformation, damage, and destruction of the welded construction truss with the optimal ratio of strength and material consumption. The objective of the study is to determine the effect of the dimensions of the standard rolled angle profile on the change in the strength of the welded truss. The field of application of the results of the work is the design, manufacture, operation, and restoration of damaged welded trusses. The research methods are the following: standardized approaches to experiment planning, field experiment, computer modeling experiment, semi-natural experiment, and statistical processing of experimental data. The design parameters of the angled rolled profile for the welded rafter truss are optimized in the paper by the criterion of minimum material consumption while maintaining the designed strength by the method of computer simulation experiment using Ansys Workbench 14.5 software package. The practical significance of the obtained results is to develop recommendations for the design, manufacture, operation, inspection, and restoration of welded trusses 2. Methodological aspects of research During operation, welded rafter trusses are exposed to various factors (workload, snow, wind, temperature, seismic effects, emergency situations, etc.). The bearing capacity of welded metal trusses depends on their structural and technological features, as well as their operating conditions. According to the classical designing methods of welded trusses, the construction parameters were determined based on the most significant impact factor, according to the construction engineer’s opinion. The remaining factors were either not considered at all or were taken into account due to a number of empirical coefficients determined by the engineer. As a result of the design, the effect of the subjective factor was noticeable. The consequence of such a subjective approach is 1.3-1.65 times understatement of the calculated indicators of the strength of the truss in comparison with the actual operational results due to the introduction of the appropriate coefficient of strength. This leads to significant material overspend for the manufacture of trusses. Modern computer technology and calculation techniques, which are based on application software packages, make it possible to comprehensively take into account a significant number of damaging factors and thus obtain design results with a significantly higher level of probability than classical methods. In the modern sense, the optimal design is a purposeful choice of construction parameters that provides the best result according to the set criteria. Such criteria can be economic ones: material consumption, cost, the amount of one-time and operating costs reduced to one dimension (reduced costs), etc., as well as physical ones, such as uniform stress, minimum mass or volume, maximum load perception, etc., which indirectly affects the efficiency of the structure as described by Moddox (2002), Haichao (2014), Garg (2015).