Effect of Laser Process on Microstructure and Fatigue Resistance of Steam Turbine Blade

The steal turbine blades, operating in steam electricity production plants are subjected to periodic circular stresses that cause fatigue failure with the passage of time. The chemical composition so steam turbine blades show that is steel 52 it has a wide range of applications, mostly in welded construction, All kinds of welded construction, wind turbines, load-lifting equipment, platform components, cranes, bridge components, and structures. This research aims to study the microstructure of these turbine blades before and after the occurrence of fatigue, and for the purpose of improvement the fatigue resistance, the blades were treated with a laser and the amount of improvement in fatigue resistance was calculated and also the change in the microstructure after laser treatment was studied. The remelting process applied with this parameter Pulse energy = 8 joules, Pulse width = 4.5 Ms., Pulse frequency = 12 Hz, Laser Average Power = 96 W, Laser peak power = 1.78 KW. The results show, after remelting process the microstructure of the specimen is smooth and increase the cyclic of fatigue comparison with specimen without leaser remelting process. So, the fatigue resistance is increased.

Truck-Lifting Prevention System Based on Vision Tracking for Container-Lifting Operation

Truck-lifting accidents are common in container-lifting operations. Previously, the operation sites are needed to arrange workers for observation and guidance. However, with the development of automated equipment in container terminals, an automated accident detection method is required to replace manual workers. Considering the development of vision detection and tracking algorithms, this study designed a vision-based truck-lifting prevention system. This system uses a camera to detect and track the movement of the truck wheel hub during the operation to determine whether the truck chassis is being lifted. The hardware device of this system is easy to install and has good versatility for most container-lifting equipment. The accident detection algorithm combines convolutional neural network detection, traditional image processing, and a multitarget tracking algorithm to calculate the displacement and posture information of the truck during the operation. The experiments show that the measurement accuracy of this system reaches 52 mm, and it can effectively distinguish the trajectories of different wheel hubs, meeting the requirements for detecting lifting accidents.

Revisiting the relationship between farm mechanization and labour requirement in India

In many developing and emerging economies, better employment opportunities in the non-farm sector have increased rural wages due to labour shortages during the peak agricultural season. Increasing wages often cause a substitution of labour for mechanical power, but extensive use of labour-saving technologies may cause labour displacement and have serious equity concerns. Using the household and individual fixed effect estimation approach, this paper analyses the relationship between different types of farm machines and labour requirements in India. The results suggest that a unit increase in the level of farm mechanization increases the demand for hired labour by 12%. Moreover, we find that the level of farm mechanization has a positive effect on women’s participation in farm work, while it decreases the probability of children participating in agriculture-related work. Disaggregated analysis based on types of farm machinery suggests that water-lifting equipment, draft power and tractors increase the probability of male household members working on their farms, while all types of farm machines, except tractors, have a positive effect on female farm labour participation. We also find that the effect of farm mechanization on the demand for hired labour decreases as the size of the farm increases.

Failures of Cranes and Lifting Equipment

The types of metal components used in lifting equipment include gears, shafts, drums and sheaves, brakes, brake wheels, couplings, bearings, wheels, electrical switchgear, chains, wire rope, and hooks. This article primarily deals with many of these metal components of lifting equipment in three categories: cranes and bridges, attachments used for direct lifting, and built-in members of lifting equipment. It first reviews the mechanisms, origins, and investigation of failures. Then the article describes the materials used for lifting equipment, followed by a section explaining the failure analysis of wire ropes and the failure of wire ropes due to corrosion, a common cause of wire-rope failure. Further, it reviews the characteristics of shock loading, abrasive wear, and stress-corrosion cracking of a wire rope. Then, the article provides information on the failure analysis of chains, hooks, shafts, and cranes and related members.

INDUSTRIAL SAFETY - 2021

The changes in the legislation adopted in 2021 on the industrial safety of hazardous production facilities that use lifting equipment and equipment operating under excessive pressure are considered

Analysis of the Occupational Risk Management at the Enterprises during Lifting Equipment Operation

The model for assessing the levels of occupational risks was introduced and is used at the mechanical engineering enterprises during lifting equipment operation. The analysis of injuries carried out six months after the start of its use and familiarization of employees with the register and the level of hazards showed a decrease in risk levels in relation to previous periods. The results of the study of the procedure for managing occupational risks when working on three types of cranes are presented: electric bridge crane; gantry crane and single-girder electric supporting bridge crane. The first two listed cranes are installed at hazardous production facilities. After drawing up a plan for assessing occupational risks at the stage of risk identification, the method of questionnaires was used to collect information about production processes and determine the register of hazards. To analyze the work of the occupational health and safety management system, a multi-level control of the technological process and ensuring its safety was introduced. In practice, the relevance and availability of the Fine — Kinney method for assessing the levels of occupational risks was confirmed. When studying the significance of the impact of the procedures (elements) of the occupational health and safety management system on the probability of a hazard and, consequently, on the final level of occupational risk, the method of expert assessments was used. The methods for formalizing assessment results proposed and implemented in the organizations reflect all the stages of the process and provide answers at any stage of the study of the occupational risk levels. The measures developed based on the results of the assessment of occupational risk levels allow to maintain safe working conditions and prevent the occurrence of hazards that lead to injuries at work.

THE QUESTION OF BOOM LIFTING EQUIPMENT OPERATION STABILITY ON A WHEELED CHASSIS

В статье представлены на рассмотрение характеристики стабильности работы стреловых грузоподъемных средств на колесном шасси в форме математических выражений. Математические выражения представлены в виде не громоздких зависимостей от конкретно заданных параметров. Качество движения зависит от возрастания линейных размеров, масс, моментов инерции, а также скоростей и других механических параметров грузоподъемных средств. Достижение стабильности работы выносных стреловых грузоподъемных средств достигается путем распределения нагрузки между утлегарью (выносной стрелой грузоподъемного средства) и опорными колесами колесного шасси. Считаем, что при существовании ряда концепцией со своими теориями. возможно определение стабильности работы стрелового грузоподъемного средства на колесном шасси. Нами установлено, что возможно обеспечить стабильность работы путем выбора целесообразных значений механических составляющих всех звеньев рабочего механизма для спланировано составленных рабочих ситуаций. В зависимости от возможного размещения грузоподъемного устройства показатели стабильности работы меняются и это подтверждают составленные нами математические выражения, которые приводятся в статье. Установлено, что путем варьирования различными вариантами положений и массой составляющих элементов конструкции грузоподъемного средства, а также графически определяя возможные варианты перемещения груза в зависимости от заданной длины утлегарьи, имеет место выражение, позволяющее определить ряд значений масс, безопасно поднимаемых грузоподъемным средством. Нами получены значения необходимых для графических построений грузовых характеристик грузоподъемного средства, выражающие зависимость между массой груза и вылетом утлегарьи с весом ее элементов. Реакции в шарнирах утлегарьи и усилия в ее составляющих звеньях возможно установить из данных грузовой характеристики. Стремление обеспечить максимальную стабильность работы грузоподъемного средства накладывает ограничения на контроль за несколькими подвижными операциями одновременно, что неблагоприятно сказывается на эффективности рабочего процесса. Установили, что обеспечение стабильности работы в поперечной и продольной плоскостях грузоподъемного средства является необходимым компонентом безопасной эксплуатации. По зависимостям для определения показателя грузового равновесия возможно определение предварительного места установки выносных опор грузоподъемного средства. Как подтверждают полученные результаты, стабильность работы грузоподъемного средства в продольном направлении определяется аналогично стабильности работы в поперечном направлении и для номинальной массы груза при наибольшем вылете утлегарьи и выставленных выносных опорах. В итоге отметим, что показателем грузового равновесия служит отношение удерживающего момента относительно ребра опрокидывания, создаваемого весом грузоподъемного средства на колесном шасси с учетом уменьшающих его дополнительных внешних нагрузок и влияния уклона площадки к опрокидывающему моменту, создаваемому рабочим грузом. The article presents for consideration the characteristics of the stability of the boom lifting equipment on a wheeled chassis in the form of mathematical expressions. Mathematical expressions are presented in the form of not cumbersome dependencies on specified parameters. The quality of movement depends on the increase in linear dimensions, masses, moments of inertia, as well as speeds, and other mechanical parameters of the lifting equipment. Achievement of the stability of the outboard boom lifting device is achieved by distributing the load between the jib boom (outboard boom of the lifting device) and the support wheels of the wheeled chassis. We believe that with the existence of a number of concepts with their theories, it is possible to determine the stability of the boom lifting device on a wheeled chassis. It has been found that it is possible to ensure the stability of work by choosing the appropriate values of the mechanical components of all links of the working mechanism for planned working situations. Depending on the possible placement of the lifting device, the stability indicators are changed, and this is confirmed by the mathematical expressions we compiled, which are given in the article. It has been established that by varying the positions and the mass of the constituent elements of the structure of the lifting device, as well as graphically defining the possible options of the load moving, depending on the given length of the jib boom, an expression takes place that makes it possible to determine a number of values of the masses safely lifted by the lifting device. There have been obtained the values of the cargo characteristics of the lifting device necessary for graphic constructions, expressing the relationship between the weight of the cargo and the overhanging of the jib boom with the weight of its elements. The reactions in the joints of the jig boom and the forces in its constituent links can be established from the data of the load characteristics. The desire to ensure maximum stability in the operation of the lifting device imposes restrictions on the control of several mobile operations at the same time, which adversely affects the efficiency of the work process. It has been established that ensuring the stability of operation in the transverse and longitudinal planes of the lifting device is a necessary component of safe operation. According to the dependencies for determining the indicator of cargo balance, it is possible to determine the preliminary installation site of the outriggers of the lifting device. As the results obtained confirm, the stability of the operation of the lifting device in the longitudinal direction is determined similarly to the stability of the operation in the transverse direction and for the nominal weight of the load with the greatest overhanging of the jib boom and the set outriggers. As a result, we note that the ratio of the holding moment relative to the overturning rib created by the weight of the lifting device on the wheeled chassis, taking into account the additional external loads that reduce it and the influence of the platform slope to the overturning moment created by the working load, serves as an indicator of the cargo balance.