Расчет Малоцикловой Усталости По Национальному Стандарту И Нормам Прочности

Конторович, Т. С.; Радин, Ю. А.

doi:10.1134/s0040363617080045

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Возможностям развития существующих нормативных процедур посвящен ряд публикаций. Круг рассматриваемых в этих работах вопросов включает более подробный анализ поведения материалов за пределами упругости [5,8,9,[12][13][14][15], разработку методов расчетного определения моментов достижения предельных состояний [16][17][18], вопросы соотношения результатов расчетов с экспериментами и практикой [7,10,19], вопросы описания накопления повреждений при длительном повторно-переменном неупругом деформировании [4,20], вопросы соотношения норм и стандартов в разных отраслях [21] или даже в пределах одной отрасли [22]. Отмечается, что для элементов атомных энергетических установок при нарушении нормальных условий эксплуатации риск-анализ должен опираться на реалистичную расчетную оценку механизмов разрушения, которая должна учитывать множество возможных типов разрушения (локальное разрушение из-за исчерпания ресурса пластичности или накопления деформации ползучести, прогрессирующее формоизменение, потерю устойчивости при ползучести и т.д.)…”

Section: недостатки и проблемы существующих методовunclassified

Limit states and safety factors under repeated loading

Chernyavsky

Ф²,

Cherniavsky

et al. 2020

PNRPU Mechanics Bulletin

View full text Add to dashboard Cite

Verification of the structures operating possibility using numerical modeling beyond the elastic limit requires standardization of safety factors and calculation methods used to get them. In the framework of the discussion on the improvement of the strength standards of the aviation and nuclear industries for structures operating under low-cycle mechanical and reversible dilatation (temperature, hydrogen) external influences, the article discusses the limiting states; the deformation properties of materials necessary for their calculation; safety factors for loads and durability; calculation methods. The article divides limit states of structures under low-cycle actions into two groups: typical, corresponding to a qualitative change in the deformation type, and individual, determined by allowable displacements and cracks for a particular structure. The following types of deformation are considered: inelastic deformation only at the running-in stage (that changes to elastic after the auspicious residual stresses develop and cyclic hardening of the material); alternating flow (that continues with the number of cycles); progressive accumulation of strains and displacements; combined deformation (when both strain span and strain increment are non-zero in a stable cycle). The types of deformation differ in possible consequences for the structure and the initial data for the calculation: mechanical properties of the material required for modeling different types of deformation should be determined by fundamentally different tests. An analysis of individual limit states without taking into account differences in the types of deformation - and thus typical limit states - may be incorrect. The main focus of the article is on typical limit states. The limit states vary depending on the stage of operation at which inelastic cyclic deformation is allowed. Inelastic deformation expands allowable load range, the expansion due to the inelastic deformation at the running-in stage only is usually more significant than additional expansion due to the continuous inelastic deformation; besides, the inelastic deformation only at the running-in stage does not demand analysis of low-cycle fatigue and accumulated strains. Further expansion of the permissible load range, as well as solution of safety problems based on risk assessments, requires a more complete study of the deformation properties of materials at the pre-fracture stage, where cyclic softening predominates.

show abstract

Section: недостатки и проблемы существующих методовunclassified

Limit states and safety factors under repeated loading

Chernyavsky

Ф²,

Cherniavsky

et al. 2020

PNRPU Mechanics Bulletin

View full text Add to dashboard Cite

show abstract

“…1). Строение этой серии детально обосновано при изучении десятков скважин, пробуренных в последние десятилетия [1][2][3][4], и закреплено в региональной стратиграфической схеме [5]. Однако отложения этой серии до сих пор не имеют изотопно-геохронологической характеристики.…”

unclassified

Rb-Sr age of the riphean glauconites of the Kamov group (Baikit anteklise, Siberian platform)

Zaitseva

Кузнецов

Ivanova

et al. 2019

Доклады Академии наук

View full text Add to dashboard Cite

A mineralogical and geochemical study was conducted and the Rb-Sr age of globular layered silicates (GPS) of the glauconite-illite series of the Dolgokta Formation from a parametric Chunkinskaya-282 drillcore was determined. The assessment of suitability of the mineral for geochronological purposes took into account the data of Mössbauer spectroscopy and modeling of the cation distribution in the GPS octahedral net. Mineralogical and crystalochemical characteristics indicate an epigenetic alteration of glauconite structure; therefore, its Rb-Sr isochronous age (1300 ± 7 Ma) is “rejuvenated” and reflects the stage of partial recrystallization. The 87Sr/86Sr ratio in dolomites of the Dolgokta and Kuyumba formations varies from 0.70602 to 0.72230, which confirms the epigenetic recrystallization. The model Rb-Sr age of glauconite, calculated taking into account the enrichment of radiogenic 87Sr, is within 1340-1400 Ma. The age estimate determines the upper limit of distribution of the Mesoproterozoic fossil Tappania, found in the Yurubchen and Dolgokta formations of the Baikit anteclise.

show abstract

Расчет Малоцикловой Усталости По Национальному Стандарту И Нормам Прочности

Cited by 2 publications

References 0 publications

Limit states and safety factors under repeated loading

Limit states and safety factors under repeated loading

Rb-Sr age of the riphean glauconites of the Kamov group (Baikit anteklise, Siberian platform)

Contact Info

Product

Resources

About