АНАЛІЗ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ ФІТИНГОВОГО СТИКУ ПАНЕЛЕЙ ВІД'ЄМНОЇ ЧАСТИНИ КРИЛА ТА ЦЕНТРОПЛАНА ТРАНСПОРТНОГО ЛІТАКА

Fitting joints are widely used in aircraft structures, and they are responsible for the interconnection of important components. The stress-strain state analysis of the fitting joint must be carried out before the performance analysis of the fitting joint. With the help of 3D modeling software (CATIA) and finite element analysis software (ANSYS), the stress-strain state of each component in the fitting joint of outer wing section was calculated in this paper. In the CATIA, the solid model is simplified and segmented according to the size of the cross section and the height of the center of gravity of the model. In the ANSYS, the beam elements are used to replace the simplified segmented model to obtain the internal force distribution of the solid model and to determine the magnitude and change law of the stress applied to the end of the solid model. When calculating the force transmitted by the fastener, the pre-tightening force of the bolt and the interaction between the surfaces of the component are taken into account, so as to simulate the real force situation well. Therefore, it is a very feasible method to use the CATIA and ANSYS to obtain the stress-strain state of components in the fitting joint of center wing section and outer wing section.The results show that under the working conditions of the fitting joint (130Mpa), the fitting of outer wing section with center section has a maximum stress of 245.79Mpa and a maximum strain of 0.0035, the stringer of outer wing section has a maximum stress of 293.17Mpa and a maximum strain of 0.0047, the lower panel of outer wing section has a maximum stress of 289.53Mpa and a maximum strain of 0.0042. The connecting bolts (M8 and M6) have a maximum stress of 686.81Mpa and a maximum strain of 0.0063, which meets the design requirements. In addition, according to the analysis results of the stress-strain state of the fitting joint of outer wing section, the force distribution of the bolts in the fitting joint of outer wing section with center section was obtained in this paper. It has been confirmed that due to the different positions and force areas of the bolts, the force distribution between rows of bolts is uneven, and the first row of bolts has a more force.

Role of Retail Price Strategy in Influencing Customer Purchase Intention

Price sensitivity was consistently a matter of worry for retailers when planning pricing strategies. The expectant reaction towards changing price is high felt among the middleclass purchasers and impact more on their purchasing decisions in India. This research plans to decide, regardless of whether the estimating special technique for the key-esteem classification, acquires a huge change in the offer of key-esteem things or not. The examination is decisive and applied the quantitative method to approve the proposed speculation. An organized poll comprising 21 inquiries was utilized to gather information through an online review. The Snowball inspecting strategy was utilized to gather information from respondents, including youthful workers, homemakers, and entrepreneurs, and gathered reactions towards the incessant value limits offered by driving hypermarkets chains and general stores in the country. The straight relapse is directed utilizing SPSS programming. Discoveries of the exploration presumed that as the Indian center section is exceptionally evaluated touchy, henceforth tremendous value limits impel brand agitating among them and even impact the pre-purchasing choice for procurement. The significant limitations of the examination were that it centered uniquely around contemplating the effect of cost special proposals on deals which is exceptionally relevant and restricted to item classes, wherein there are different factors additionally which can altogether affect deals. We have decided the effect of one develop over another under the shadow of key-esteem classifications, while further exploration can check the effect separately or on different classifications too. The exploration is absolutely experimental and directed interestingly by the analyst to imply the significance of value advancement procedure in consonance to deals. The newly gathered essential information utilized for approval.

Modeling Uniaxial Bond Stress–Slip Behavior of Reinforcing Bars Embedded in Concrete with Different Strengths

This paper aims to study the uniaxial bond stress–slip characteristics of reinforcing bars embedded in concrete with different strengths. Tests were conducted on tension–pull specimens that had a cross-sectional dimension with a reinforcing bar embedded in the center section. The experimental variable was the concrete compressive strength (20, 40, and 60 MPa). The test results show that in the specimen subjected to any fixed load, the maximum value of the concrete strain occurred around the central position, and its value increased as the compressive strength of the concrete increased. Depending on the embedded position of the steel bars, the bond stress–slip relationship was also different. In addition, the analytical results indicate that the proposed bond stress–slip constitutive relationship is very accurate in describing the true bond stress–slip relationship.

Serological Investigations of Bluetongue Virus (BTV) among Sheep and Goats in Kassala State, Eastern Sudan

Bluetongue (BT) is an infectious, noncontagious, vector-borne viral disease of wild and domestic ruminants. BTV is a member of the Orbivirus genus of the family Reoviridae. The present study aimed to investigate the seroprevalence of BTV in sheep and goats in Kassala State, Sudan. It also aimed to determine risk factors associated with BTV infection. The study was carried out by a structured questionnaire survey, and a total of 809 serum samples were collected from sheep (n = 459) and goats (n = 350) from 9 different localities in Kassala state. These samples were analyzed using a competitive enzyme-linked immunosorbent assay (cELISA) for the detection of BTV antibodies. The overall seroprevalence of BTV was 91.2% (738/809). In goats, the prevalence of BTV antibodies was comparatively higher (100%) than in sheep (84.5%). The prevalence differed between localities and was the highest in the center section of Kassala and Western Kassala (100%). Animals aged 6–11 months were highly infected (93.9%) compared to 1-year-old (85.5%). Caprine species was more likely to be infected (100%) than ovine (84.5%), and females were highly infected (92.8%) than males (85.5%). BTV infections were higher in the winter season (91.4%). Risk factors that showed significant associations with cELISA positivity included locality and sex (p≤0.003) and species and age (p≤0.000). Factors significantly associated with cELISA positivity in multivariate analysis were localities, species, age, and sex. BTV infection is prevalent in sheep and goat populations in Kassala state.

METHOD OF CALCULATING THE LIFT COEFFICIENT FOR A WIG’S COMPOUND WING FLYING CLOSE TO THE GROUND

In the design and characteristics justification of WIG crafts, determination of optimal aerodynamic and moment coefficients and their ratio is still one of the most important problems. Values and ratios of these coefficients provide not only technical tasks performance, but also safe operation of a WIG craft within the framework of AP standards and rules of water transport operation. The paper is devoted to the method of calculating the Cy lift coefficient for the complex compound wing with washers by using the superposition method and verification of calculated data with experimental values. The study was based on TsAGI-876 wing profile characteristics at various relative flight heights.Calculation of the aerodynamic Cy coefficient is performed in several stages:1. Calculation of the aerodynamic Cy coefficient for the center section;2. Calculation of aerodynamic Cy coefficient for the console section;3. Calculation of the total Cy coefficient by using the superposition method.The proposed method of calculation provides an accuracy of up to 93%, which can be considered a satisfactory result for preliminary design of types «B» and «C» WIG crafts.

Experimental Determination of the Ratcheting of the Porosity for the Study of Ductile Rupture Under Cyclic Loading Conditions

It is known that for ductile porous materials, cyclic loadings lead to lower fracture strains than monotone ones. This reduction of ductility probably arises from an effect called “ratcheting of the porosity” that consists of a continued increase of the mean porosity during each cycle with the number of cycles. Finite element based micromechanical simulations confirmed this interpretation. Recently the authors proposed a Gurson-type “layer model” better fit that Gurson’s original one which does not predict the ratcheting of the porosity, for the description of the ductile behavior under cyclic loading conditions. A very good agreement was obtained between the results of the micromechanical simulations and the model predictions for a rigid-hardenable material. Yet, the ratcheting of the porosity is a consequence of both hardening and elasticity; and the theory of sequential limit analysis used in order to get the “layer model” is strictly applicable in the absence of elasticity. Based on an expression of the porosity rate accounting for elasticity, a proposal was made to improve the new model with regard to elasticity. Simultaneously to this theoretical work, an experimental program was conducted on a model material in order to assess experimentally this new model. The material is a HIPed 316L stainless steel, with Al2O3 almost spherical inclusions acting like porosities, complying with the hypothesis made to derive the theoretical model. Notched tensile specimens, with a center section of 4mm, were cyclically loaded. Several tomographies were performed at ESRF, using a 120 keV beamline and 3x3 microns detector, in order to prove experimentally the ratcheting effect of the porosity. The void growth through the cycles is precisely described and the experimental results could then be processed and compared to the numerical porosities predictions of the model. This paper presents the experimental activity of this PhD program.

КОНЦЕПЦИЯ ПРИМЕНЕНИЯ ПРОГРАММНО-ТЕХНИЧЕСКОГО КОМПЛЕКСА В СРЕДЕ ВИРТУАЛЬНОЙ РЕАЛЬНОСТИ 3D-ЦИФРОВОЙ КОНСТРУКТОРСКО-ТЕХНОЛОГИЧЕСКОЙ ПОДГОТОВКИ ПРОИЗВОДСТВА АГРЕГАТОВ САМОЛЕТНЫХ КОНСТРУКЦИЙ

A general concept has been developed for application of a software and hardware complex in a virtual reality environment in 3D-digital design and technological preparation of production, implemented by the method of synthesizing an electronic model of a product — the center section of an An-148 short-range aircraft in integration with corporate CAD, PDM, BP systems. The composition of software and hardware used in the development of the methodology corresponding to the level of similar systems of foreign aircraft manufacturers, as well as the composition and architecture of the developed system of virtual reality and the principles of its operation are given. The content of the stages of a 3D-digital design and technological preparation of production in the context of integrated information production systems has been outlined, the center-plane of the An 148 aircraft has been tested in a virtual reality and simulation environment.

МЕТОДИКА РЕАЛІЗАЦІЇ СИСТЕМИ АВТОМАТИЗОВАНОГО КОНСТРУЮВАННЯ ТА ВИГОТОВЛЕННЯ ПРИСТОСУВАНЬ ПРИ ТЕХНОЛОГІЧНІЙ ПІДГОТОВЦІ ЛІТАКОБУДІВНОГО ВИРОБНИЦТВА В РЕЖИМІ ВІРТУАЛЬНОЇ РЕАЛЬНОСТІ

The technique of application and practical implementation of the technology of virtual reality in the technological preparation of the production of domestic civil aircraft has been developed. The technique is used to implement the assembly of parts, assemblies and accessories in the aggregate and assembly production on the example of the center section of the An-148 aircraft and the creation of technological planning of workplaces based on designed electronic models. The main provisions of the concepts of system design and manufacture of devices in the mode of virtual reality. The principles of its implementation on the basis of electronic design and technological layouts are proposed. The composition of the main components of the systems and the sequence of stages of stimulation of production technologies for ЗD, digital design and technological preparation of production are given.