Central Asian Journal of STEM

ҲАР ХИЛ СХЕМАДАГИ КРИВОШИП-ШАТУНЛИ МЕХАНИЗМЛАРНИНГ КИНЕМАТИКАСИНИ АНИҚЛАШ ВА УЛАРНИ БАҲОЛАШ

2023-05-23T07:06:16+00:00

This article presents the kinematic diagrams of conventional and planetary crankshaft mechanisms. The effect of changing the parameters of the planetary crankshaft mechanisms on the trajectory of the crankshaft head was analyzed. Trajectories were constructed for various parameters and the geometric positions of the points corresponding to the rotation angle of rotation of the curve were determined. At the same time, specific aspects of the design schemes for internal and external coupling of planetary crankshaft mechanisms were theoretically analyzed. Piston displacement, speed, and acceleration were calculated, and drawn graphs according to the crankshaft rotation angle for the conventional crankshaft mechanism.

EVALUATION OF WIND-INDUCED FATIGUE DAMAGE FOR EXISTING STRUCTURES CONSIDERING DIRECTIONAL EFFECTS

2023-05-23T11:33:15+00:00

In many buildings, especially high rise ones, wind have been major problem by causing vibration as well as fatigue issues resulted from fluctuations of wind in random flowing. When the structures are designed appropriately enough, they are less likely to suffer from damage caused by wind induced fatigue. However, in some cases, the structures are under designed and fatigue damage can cause non negligible damage and components may start fatigue crack initiation when larger stress is concentrated in some parts. And this result in complete or partially failure of components of parts.

МОДЕЛИРОВАНИЕ ОПТИМАЛЬНОГО РАСПРЕДЕЛЕНИЯ ВОДЫ В РЕЧНЫХ РУСЛАХ И МАШИННЫХ КАНАЛАХ АМУ-БУХАРА

2023-05-23T09:09:01+00:00

В этом парагрефе рассматривается метод оптимального распределения вод по трассам канала «Аму-Бухара» откуда впитывает воду водохранилище «Куюмазар», часть воды берется из «Амударьи» насосными станциями. Настоящей статьи рассматривается задача оптимального распределения воды в оросительной сети и является одним из актуальных задач для нашего региона и требует математического моделирования распределения воды между потребителями с учетом забор воды для орошения, фильтрация, испарение и. т. д. – т.е. потеря вдоль трассы каналов. Рассмотрим задачу на примере Реки Амударьи в распределения воды для водохранилищ «Куюмазар» при подъёме воды насосными станциями в гидроузел «Куюмазар».

МОДЕЛИРОВАНИЕ СОРОУДЕРЖИВАЮЩЕГО МЕХАНИЗМА С УЧЁТОМ ВИХРЕВЫХ ЗОН АВАНКАМЕРЫ

2023-05-23T09:02:38+00:00

Это изобретение ненадёжно и дорого в эксплуатации, так как перемещение диска и диафрагмы должно производиться синхронно работающими силовыми гидроцилиндрами, причем диску движение передается штоком, проходящим внутри полого вала рабочего колеса.

Yusupov S.S MAMLAKATIMIZDA ELEKTROMOBILLARNI QO‘LLAB-QUVVATLASH BO‘YICHA YARATILAYOTGAN IMKONIYATLARNING TAHLILI VA INFRATUZILMANI YARATISHNING AHAMIYATI

2023-05-23T07:26:13+00:00

Annotation. This article analyzes the current stages of the development of electric cars, their differences from classic vehicles, types of electric cars, and descriptions of the batteries used. In addition, a comparative analysis of energy generation and use, and environmental and economic aspects of electric vehicle operating costs are calculated. Also, the stages of infrastructure development of their battery charging stations and the mechanisms of transition to green energy technologies in our country through the production of electric cars were analyzed.

P-to‘lqinli o‘tkazuvchan ochiq halqadagi nol energiyali majorana rejimlari

2023-05-25T09:23:31+00:00

Ma’lum bir qiymatda sozlangan magnit oqim tomonidan hosil qilingan, tartibsiz chekli uzunlikdagi p-to‘lqinli bir o‘lchovli o‘ta o‘tkazuvchan halqada nol energiyali Majorana rejimlarining paydo bo‘lishini muhokama qilamiz. Majorana rejimlarining paydo bo‘lishini ko‘rib chiqamiz. Cheklangan uzunlikdagi uzilgan halqada magnit oqimi ni Majorana rejimlarini Kitaev nazariyalariga asoslangan holda tahlil qilamiz.

DESIGN AND IMPLEMENTATION OF A SPRING-MASS RESONATOR FOR TEACHING ASSISTANCE

2023-04-27T04:15:51+00:00

Over time, the issue of maintaining, restoring, and consolidating structural elements has become increasingly important for engineers and designers in the mechanical engineering sector. Many structures built in the past using outdated methods are now considered structurally unsafe according to modern standards. Replacing these structural elements is often costly and time-consuming, so strengthening has become the preferred method to enhance load capacity and extend the lifespan of these structures.

The purpose of this work is to introduce the concept of vibration to young people and explain how exciting it is to study this field. The goal is to calculate the vibration behavior of different materials when subjected to external excitation. The method involves characterizing the resonant response of a spring-mass system that is excited by a sine-wave forcing term applied as a vertical force to the suspended mass. The prototype of the testing machine is made from second-hand materials that are readily available. The young modulus is obtained from the resonance frequency, and the non-linear coefficient is calculated using the backbone approach from resonance profile variations as a function of the forcing term amplitude. The method is highly sensitive, to the point that a maximum excitation amplitude of the order of the non-linear coefficient is required. The testing machine provides the necessary sensitivity at such small excitation amplitudes and the capability of evaluating very small damping values, as expected in high strength low damping materials. The sensitivity is ensured by an optical position sensor.

CONSIDERING DIRECTIONALITY EFFECTS OF WIND ON EXISTING STRUCTURES USING METEOROLOGICAL OBSERVATIONS DATA.

2023-05-23T11:34:12+00:00

In many buildings, especially high rise ones, wind have been major problem by causing vibration as well as fatigue issues resulted from fluctuations of wind in random flowing. Wind flow randomness have been studied in many scientific researches and is convinced to follow some probabilistic models which helps researchers to predict the behavior in some way. If probabilistic models are fed with enough meteorological data obtained from weather observations, then reliable predictions or simulations would be possible to make.

Introduction to OpenSees

2023-05-23T09:08:22+00:00

OpenSees (Open System for Earthquake Engineering Simulation) is an open software that simulates the dynamics of structures and geotechnical structures. Currently, this program analyzes the behavior of structures in various natural disasters such as fire, wind, and earthquake using finite elements. In this article, we will get acquainted with the OpenSees program, look at its simple construction and get an understanding of how OpenSees works. Its differences and advantages from other similar programs are analyzed.

TECHNOLOGICAL FEATURES OF PROCESSES OF SIMULTANEOUS STEEL SATURATION WITH NITROGEN AND CARBON

2023-05-23T08:46:54+00:00

The article discusses the technological feature of the processes of saturation of steel with nitrogen and carbon using a wide range of saturation temperatures. Depending on the saturation temperature intervals, high-temperature, medium-temperature, low-temperature nitrocarburizing processes are distinguished. However, the use of gas nitrocarburizing in conditions of single and small-scale production leads to an increase in the cost of the process. In the course of the research, it was found that carbonitrification in a vacuum environment made it possible to drastically reduce the time of saturation of the steel surface with nitrogen and carbon. The advantage of the method is also the technological purity of the process and the possibility of precise control of the saturation depth.

Nonlinear electromagnetic spatial solitons in the resonant value of electromagnetic waves

2023-05-25T09:32:23+00:00

For such a multi-valued nonlinear magnetic response, the domains with different values of the magnetic permeability ”excited” by the spatial soliton can be viewed as effective induced left-handed waveguides which make possible the existence of single- and multi-hump soliton structures. Due to the existence of such domains, the solitons can be not only symmetric, but also antisymmetric and even asymmetric. Formally, the size of an effective domain can be much smaller than the wavelength and, therefore, there exists an applicability limit for the obtained results to describe nonlinear waves in realistic composite structures.