scholarly journals Life-Time Calculation of Spiroid Gearbox in the Drive of Cable-Assembly Mechanism of the Electric Loader

2017 ◽  
Vol 20 (2) ◽  
pp. 24
Author(s):  
V N Anferov ◽  
A P Tkachuk ◽  
A V Zaitsev
Keyword(s):  
Life Time ◽  
Assembly Mechanism ◽  
Time Calculation ◽  
Electric Loader ◽  
Cable Assembly

Рассмотрен метод определения ресурса спироидного редуктора в приводе кабелесборочного механизма электропогрузчика. Метод основан на учете конкретных условий эксплуатации электропогрузчикав процессе выполнения погрузочно-разгрузочных работ и, как следствие, режимов нагружения кабелесборочного механизма. Электропогрузчики широко применяются в промышленности, на транспорте, в строительстве и горном производстве при проведении погрузочно-разгрузочных работ. Одним из самых распространенных видов являются универсальные электропогрузчикис приводом от аккумуляторных батарей. Наиболее часто их используют для погрузочных и разгрузочных работ в крытых складских помещениях. В результате расчетов получен прогнозируемый ресурс спироидного мотор-редуктора кабелесборочного механизма при постоянном и переменном режимах нагружения, с учетом предельного износа зубьев спироидного колеса и продолжительности цикла работы кабелесборочного механизма. Метод учитывает основные характеристики процесса выполнения рабочего цикла электропогрузчиком при транспортировании, погрузке и выгрузке грузов. Данные характеристики учитываются соответствующей усредненной тахограммой рабочего цикла электропогрузчика. Результаты расчетов прогнозируемого ресурса по данному методу позволяют на этапах проектирования кабелесборочного механизма более точно спрогнозировать ресурс спироидного мотор-редуктора с учетом режима нагружения, а также условий эксплуатации электропогрузчика.

Failure Mechanism of Pure Nickel (Ni 200/201) under Thermo-Mechanical Loading

2007 ◽  
Vol 348-349 ◽  
pp. 793-796 ◽  
Author(s):  
Hubert Koeberl ◽  
Gerhard Winter ◽  
Martin Riedler ◽  
Wilfried Eichlseder
Keyword(s):  
Cyclic Loading ◽  
Failure Mechanism ◽  
Thermal Barrier Coatings ◽  
Low Cycle Fatigue ◽  
Life Time ◽  
Damage Mechanism ◽  
Pure Nickel ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Time Calculation

Cyclic loading of metallic engineering components at constant elevated or fluctuating temperature causes a complex evolution of damage which be can hardly be described in a unique and straightforward manner. Often the thermal behaviour of the base metals is to weak, so thermal barrier coatings were needed. Nickel is generally used for such thermal barrier coatings. Therefore it is necessary to study the thermo-mechanical fatigue (TMF) of this material. The lifetime of these coatings is very strong affected by the temperature loading in general, both described by nodal temperatures and their local gradient. The thermal cyclic loading takes place as thermo-mechanical and low cycle fatigue (LCF) damage regime. To classify the thermo-mechanical failure mechanism of pure nickel, OP (out of phase) and IP-TMF (in phase) test series were examined. The use of damage parameters like the unified energy approach make sense, a more detailed life time calculation for pure Nickel can be done by using the Neu-Sehitoglu model. Summary, thermomechanical loadings activate multiple damage mechanism. Surface embrittlement by oxidation is the major distinctive mechanism in addition to pure fatigue damage. Different lifetime approaches were tested and analysed to fulfil the requirements for the fatigue analysis of nickel made components.

A mathematical model of damage accumulation taking into account microstructural effects

1993 ◽  
Vol 4 (3) ◽  
pp. 225-240 ◽  
Author(s):  
G. I. Barenblatt ◽  
V. M. Prostokishin
Keyword(s):  
Damage Accumulation ◽  
Blow Up ◽  
Life Time ◽  
Damage Parameter ◽  
Accumulation Process ◽  
Damage Distribution ◽  
Initial Damage ◽  
First Results ◽  
Time Calculation ◽  
Stress Dependent

It is shown that the influence of microstructure in the damage accumulation process leads to a nonlinear diffusion effect, with a strongly stress-dependent diffusion coefficient. A nonlinear parabolic equation with a source term is obtained for the damage parameter. This equation is relevant to blow-up and quenching problems well known to mathematicians with rupture corresponding to blow-up or quenching. However, the damage accumulation equation possesses an additional nonlinearity due to the non-healing of damage. Depending on the value of a dimensionless constant parameter (the ratio of a properly defined microstructural length-size to a characteristic length-size of the initial damage distribution), two essentially different types of damage accumulation process appear to be possible for a given initial damage distribution over the bar length. In processes of the first type, the damage accumulation remains non-homogeneous over the length of the bar, so that the lifetime for the whole specimen is determined by the maximal initial damage within the bar. For processes of the second type the damage distribution over the specimen at first becomes homogeneous (at least in a considerable part of specimen), and then the damage accumulation proceeds uniformly over all or part of the specimen. The lifetime for processes of the second type is essentially longer than the first. Results of a numerical experiment based on the proposed model are presented. In particular, the origin and development of damage propagation waves is demonstrated. Also, it is demonstrated that when there is substantial damage transfer, the ultimate value of the damage parameter in the life-time calculation is of no significance.

scholarly journals Fission life-time calculation using a complex absorbing potential

2016 ◽  
Vol 122 ◽  
pp. 01004
Author(s):  
Guillaume Scamps ◽  
Kouichi Hagino
Keyword(s):  
Life Time ◽  
Time Calculation

SEM and Auger microanalysis studies of Cu-Be dynode surfaces at each activation condition

1978 ◽  
Vol 36 (1) ◽  
pp. 524-525
Author(s):  
T. Koshikawa ◽  
Y. Fujii ◽  
E. Sugata ◽  
F. Kanematsu
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Life Time ◽  
Activation Process ◽  
Beam Diameter ◽  
Activation Temperature ◽  
Electron Multiplier ◽  
Activation Condition ◽  
Activation Conditions

The Cu-Be alloys are widely used as the electron multiplier dynodes after the adequate activation process. But the structures and compositions of the elements on the activated surfaces were not studied clearly. The Cu-Be alloys are heated in the oxygen atmosphere in the usual activation techniques. The activation conditions, e.g. temperature and O2 pressure, affect strongly the secondary electron yield and life time of dynodes.In the present paper, the activated Cu-Be dynode surfaces at each condition are investigated with Scanning Auger Microanalyzer (SAM) (primary beam diameter: 3μmϕ) and SEM. The commercial Cu-Be(2%) alloys were polished with Cr2O3 powder, rinsed in the distilled water and set in the vacuum furnance.Two typical activation condition, i.e. activation temperature 730°C and 810°C in 5x10-3 Torr O2 pressure were chosen since the formation mechanism of the BeO film on the Cu-Be alloys was guessed to be very different at each temperature from the results of the secondary electron emission measurements.

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