PSI - Issue 13

V. Moskvichev / Procedia Structural Integrity 13 (2018) 2114–2119 V. Moskvichev / Structural Integrity Procedia 00 (2018) 000 – 000

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defect size K c , J c , K ec characteristics of the static fracture toughness of materials C, n characteristics of the cyclic fracture toughness of materials Ф intensity of occurrence of a given limit state T safe life of a structure (average time) R(P, τ) reliability function R(DM) reliability at the beginning of service R( τ, σ) reliability during operation

1. Introduction The current stage of development of the technosphere has a number of particularities. There is a trend to build up complex technical systems (CTS). Scientific and technical progress causes a dilemma: - a tremendous pace of development of the technosphere in the 20th century and outstanding achievements in different areas (electronic, nuclear, space, aviation, energy and chemical engineering, genetic engineering, etc.); - the emergence and growth of previously unknown potential and real threats to man, society and natural environment from the technosphere objects. Conventional methods of securing CTS do not prevent disasters due to excessive strength and redundancy. To minimize modern technogenic threats, research is required in the field of monitoring systems, diagnostics, reliability analysis, residual life, security and safety of CTS. The development of CTS causes the growth of structural elements number, controlled parameters, unit capacity of objects, number of damaging factors and loses in the event of disasters. In such conditions, the balance of the CTS security requirements and the necessary material, scientific, technical and financial resources must be struck. A crisis situation occurs when this balance is violated (Figure 1), when the necessary or expended resources are not able to meet the safety requirements.

Fig. 1. Trends of technical systems development To ensure the safety of CTS, it is necessary to solve the tasks of risk assessment R (t), robustness L (t), security Z (t), reliability P (t), durability T (t) and strength ensuring F (t). The overall level of security will be determined by the parameters and quantitative estimates of the corresponding functions. ( ) = { ( ), ( ), ( ), ( ), ( )} (1)