Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium
Key mechanical properties used in low-cycle strength and durability calculations are the strength (proportional limit stress, <i>σ<sub>pr</sub></i>; relative yield strength, <i>σ</i><sub>0.2</sub>; and ultimate tensile stress, <i>σ<sub>u<...
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MDPI AG
2021-06-01
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author | Žilvinas Bazaras Vaidas Lukoševičius Andrius Vilkauskas Ramūnas Česnavičius |
author_facet | Žilvinas Bazaras Vaidas Lukoševičius Andrius Vilkauskas Ramūnas Česnavičius |
author_sort | Žilvinas Bazaras |
collection | DOAJ |
description | Key mechanical properties used in low-cycle strength and durability calculations are the strength (proportional limit stress, <i>σ<sub>pr</sub></i>; relative yield strength, <i>σ</i><sub>0.2</sub>; and ultimate tensile stress, <i>σ<sub>u</sub></i>) and strain properties (proportional limit strain, <i>e<sub>pr</sub></i>; percent area reduction, <i>ψ</i>; and percent area reduction at failure, <i>ψ<sub>u</sub></i>). When selecting the key mechanical properties provided in the specifications, an error may be made due to the failure to account for a series of random factors that determine the distribution of properties. The majority of research papers dealing with statistical descriptions of the low-cycle strain properties do not look deeper into the distribution of mechanical properties and the diagram parameters of strain characteristics. This paper provides a description of the distribution patterns of mechanical properties, statistical parameters, and low-cycle fatigue curves. Log-normal distribution generated the lowest values for the coefficient of variation of one of the key statistical indicators, suggesting that log-normal distribution is superior to normal or Weibull distribution in this respect. The distribution of low-cycle strain parameters exceeded the distribution of mechanical properties considerably. Minimum coefficients of variation of the parameters were generated at normal distribution. The statistical analysis showed the lower distribution of the durability parameters compared to the distribution of parameters of the strain diagrams. The findings of the paper enable a revision of the durability and life of the structural elements of in-service facilities subject to elastoplastic loading by assessing the distribution of mechanical characteristics and low-cycle strain parameters as well as the permissible distribution limits. |
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spelling | doaj.art-aefcbed8ca98412dab9a373b0dd629e32023-11-21T22:51:22ZengMDPI AGMetals2075-47012021-06-0111691810.3390/met11060918Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and AluminiumŽilvinas Bazaras0Vaidas Lukoševičius1Andrius Vilkauskas2Ramūnas Česnavičius3Faculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentų Str. 56, 51424 Kaunas, LithuaniaFaculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentų Str. 56, 51424 Kaunas, LithuaniaFaculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentų Str. 56, 51424 Kaunas, LithuaniaFaculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentų Str. 56, 51424 Kaunas, LithuaniaKey mechanical properties used in low-cycle strength and durability calculations are the strength (proportional limit stress, <i>σ<sub>pr</sub></i>; relative yield strength, <i>σ</i><sub>0.2</sub>; and ultimate tensile stress, <i>σ<sub>u</sub></i>) and strain properties (proportional limit strain, <i>e<sub>pr</sub></i>; percent area reduction, <i>ψ</i>; and percent area reduction at failure, <i>ψ<sub>u</sub></i>). When selecting the key mechanical properties provided in the specifications, an error may be made due to the failure to account for a series of random factors that determine the distribution of properties. The majority of research papers dealing with statistical descriptions of the low-cycle strain properties do not look deeper into the distribution of mechanical properties and the diagram parameters of strain characteristics. This paper provides a description of the distribution patterns of mechanical properties, statistical parameters, and low-cycle fatigue curves. Log-normal distribution generated the lowest values for the coefficient of variation of one of the key statistical indicators, suggesting that log-normal distribution is superior to normal or Weibull distribution in this respect. The distribution of low-cycle strain parameters exceeded the distribution of mechanical properties considerably. Minimum coefficients of variation of the parameters were generated at normal distribution. The statistical analysis showed the lower distribution of the durability parameters compared to the distribution of parameters of the strain diagrams. The findings of the paper enable a revision of the durability and life of the structural elements of in-service facilities subject to elastoplastic loading by assessing the distribution of mechanical characteristics and low-cycle strain parameters as well as the permissible distribution limits.https://www.mdpi.com/2075-4701/11/6/918probabilitydurabilitylow-cycle fatiguenormal distributionslog-normal distributionWeibull distribution |
spellingShingle | Žilvinas Bazaras Vaidas Lukoševičius Andrius Vilkauskas Ramūnas Česnavičius Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium Metals probability durability low-cycle fatigue normal distributions log-normal distribution Weibull distribution |
title | Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium |
title_full | Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium |
title_fullStr | Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium |
title_full_unstemmed | Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium |
title_short | Probability Assessment of the Mechanical and Low-Cycle Properties of Structural Steels and Aluminium |
title_sort | probability assessment of the mechanical and low cycle properties of structural steels and aluminium |
topic | probability durability low-cycle fatigue normal distributions log-normal distribution Weibull distribution |
url | https://www.mdpi.com/2075-4701/11/6/918 |
work_keys_str_mv | AT zilvinasbazaras probabilityassessmentofthemechanicalandlowcyclepropertiesofstructuralsteelsandaluminium AT vaidaslukosevicius probabilityassessmentofthemechanicalandlowcyclepropertiesofstructuralsteelsandaluminium AT andriusvilkauskas probabilityassessmentofthemechanicalandlowcyclepropertiesofstructuralsteelsandaluminium AT ramunascesnavicius probabilityassessmentofthemechanicalandlowcyclepropertiesofstructuralsteelsandaluminium |