| Abstract [eng] |
In this master thesis alloy structural steels and their weld joint materials cyclic stress–stain curves parameters A1, α, sT dependences on mechanical characteristic in the typical range at room and elevated temperatures are determined. Consistent statistical analysis of experimental results shown, that data is accidental, independence and normal distributed, also correlation - regression analysis shown, that almost for all groups of the materials exists a significant linear correlation between cyclic stress–stain curves parameters and modified plasticity criterion. In this final work, for parameters A1, α, sT from mechanical properties to determine, was calculated analytical dependence coefficients, also regression equations adequacy was verified. Determining value of deformation parameters from modified plasticity criterion in typical range, is better way, because the results is more accurate this is because for almost all computed and experimental characteristics results dispersion in ranges are lower comparing with total groups of alloy steels and their weld joint materials results dispersion. In this master thesis are suggested linear regression coefficients from modified plasticity criterion, which can be used for preliminary evaluation of lifetime for engineering industries machines considering of their operational environment, working temperature and what materials are used for machine‘s construction. Master's thesis has been read and discussed in May 15, 2013 at Siauliai University Faculty of Technology of the 8th International Scientific Conference of “Young Scientists\". Cyclic stress–stain curves dependences on mechanical characteristic in the typical range. |
