Optimal structures design: accounting of costs and relative accidents risk

Introduction: the article considers the formulation and solution of the problem of optimizing structures. It takes into account the ratio of the cost of manufacturing the object and the risks of material losses in emergencies related to the rapid removal of supports. The choice of the local damage scenario is justified. The assessment of risks arising from emergencies is a significant problem. The solution to it can primarily increase the safety of load-bearing building structures. Materials and methods: the two-step computational procedure is used, which includes an evolutionary search on discrete sets of design parameters and the calculation of the emergencies risks at different periods of the carrier system life cycle. At the first stage, a variant of the object is synthesized using a genetic algorithm. In this case, the evaluation of its stress-strain state is carried out taking into account the dynamic effects arising from possible local damage to the supports. The second stage consists of the calculation of the integral value of the relative risk of material losses in an emergency. It includes the failures related to both the statistical nature of the loads and the mechanical characteristics of materials, as well as the onset of various scenarios of local damage. Results: the technique for selecting a cost-effective rational design-based solution for beam structures with a higher level of responsibility has been developed. The considered example of the optimal design of a steel beam construction has illustrated the efficiency of the proposed approach. Conclusions: the research results showed that it is unacceptable to carry out the optimization of the design solution, considering only the minimum cost of structures in buildings of a higher level of responsibility. The most rational design decision on the criterion of minimizing costs and risks is the object that ensures the persistence of the structure during the emergency removal of only one support. The considered technique is recommended to using in computer-aided design of load-bearing structures.