Critical plane approach in stage i and stage ii of fatigue under multiaxial loading

This paper deals with the estimation problem of the critical plane orientation in multiaxial fatigue failure criteria. Experimental results from multiaxial proportional, nonproportional cyclic loading and variable-amplitude bending and torsion were used to determine the macroscopic fracture plane orientations and the fatigue lives. It was concluded that more important than macroscopic fracture plane orientation is the evolution (Stage I, Stage II) of fracture planes and an appropriate choice of the fatigue failure criterion for the fatigue life estimation

Everbearing Strawberries

In recent years, a number of new varieties have been developed which increase the reliability of everbearing plantings. Here are descriptions of the newer varieties plus information on best cultural systems

Gender Roles in Small Holder Dairy Farming: Pertinent Issues on Access and Control over Dairy Farming in Arumeru District, Tanzania

A study on gender roles in dairy farming and management was conducted in Arumeru district, Tanzania. The study involved women in dairy farming groups and those not in groups. The objective of this study was to assess gender role in dairy farming and management, access and control over income obtained as well as, animal ownership, decision making  and opportunities in dairy farming system in Arumeru. Cross sectional research design was adopted using structured questionnaires to collect information from households from six villages namely Bangata, Sasi, Inshupu, Enaboishu, Sokoni II and Nkoaranga. Descriptive analysis and Chi-square were used to test the statistical significance of categorical and continuous data respectively. The results showed that women contribute more labour force in dairy management than men, those women who were not in groups did not have a full access and control over dairy farming enterprise. Furthermore, it was observed that those women in groups were in a good position to overcome traditional practice. Women who belonged to groups controlled and had access to resources such as livestock (dairy cattle) and income generated from them. However, since most of the farmer groups were still infants, it has been recommended that the women groups should get financial assistance from the government agencies. Similarly, in conjunction with encouraging more women to join groups, gender relations in dairy management should be reassessed to minimize the work load burden to women which affects the level of production and sustainability of the dairy enterprise. Keywords: Access and control, dairy management, gender, women groups.

Comparison of the calculated and experimental fatigue lives under non-proportional bending with torsion of 10hnap steel

The paper contains the results of fatigue tests of 10HNAP steel under nonproportional bending with torsion. The circular smooth specimens were tested. The tests were carried out at the fatigue test stands MZGS-200PL and MZGS-200L. The best results of experimental and calculation lives consistence for the considered materials was obtained using the criterion of maximum shear stresses in the critical plane and the Palmgren-Miner hypothesis of damage accumulation

Area and point approaches in fatigue life evaluation under combined bending and torsion loading

We present a new nonlocal approach to nonuniform stress distribution, consisting in reduction of stresses to representative local ones in the critical plane for fatigue life calculation. The shear and normal stresses are averaged in two overlapping areas of different sizes on the critical plane. The proposed method is compared with the point (in critical distance) method and both are verified by fatigue tests under combined bending and torsion. Verification is done for the experimental and calculated fatigue lives with use of two multiaxial fatigue failure criteria.Представлен новый нелокальный подход к неравномерному распределению напряжений, который заключается в приведении напряжений к представительным локальным напряжениям в критической плоскости при расчете усталостной долговечности. Касательные и нормальные напряжения усредняются по двум перекрывающимся площадям различного размера, находящихся в критической плоскости. Проведено сравнение предлагаемого метода с точечным методом (по критическому расстоянию), выполнена проверка обоих методов при испытаниях на усталость в условиях совместного нагружения при изгибе и кручении. Проверка осуществлялась по полученным экспериментальным и расчетным значениям усталостной долговечности с применением двух критериев усталостного разрушения при сложном напряженном состоянии

Fatigue life under non-Gaussian random loading from various models

Fatigue test results on the 10HNAP steel under constant amplitude and random loading with non-Gaussian probability distribution function, zero mean value and wide-band frequency spectrum have been used to compare the life time estimation of the models proposed by Bannantine, Fatemi–Socie, Socie, Wang–Brown, Morel and Łagoda–Macha. Except the Morel proposal which accumulates damage step by step with a proper ethodology, all the other models use a cycle counting method. The rainflow algorithm is used to extract cycles from random histories of damage parameters in time domain. In the last model, where a strain energy density parameter is employed, additionally spectral method is evaluated for fatigue life calculation in the frequency domain. The best and very similar results of fatigue life assessment have been obtained using the models proposed by Socie and by Łagoda–Macha, both in time and frequency domains for the last one.With the support of the Commission of the European Communities under the FP5, GROWTH Programme, contract No. G1MA-CT-2002-04058 (CESTI)

Weak continuous monitoring of a flux qubit using coplanar waveguide resonator

We study a flux qubit in a coplanar waveguide resonator by measuring transmission through the system. In our system with the flux qubit decoupled galvanically from the resonator, the intermediate coupling regime is achieved. In this regime dispersive readout is possible with weak backaction on the qubit. The detailed theoretical analysis and simulations give a good agreement with the experimental data and allow to make the qubit characterization.Comment: 4 pages, 3 figures, to be published in Phys. Rev.