The Pusher as an Object of the Simulation Model in the Tasks of Studying Cyclic Mechanisms Dynamics

The cyclic mechanism is one of the basic automatic machines components. It is the cyclic mechanisms that define the performance and reliability limits of these machines. The methods for assessing the automatic machines reliability are based on data of dynamic forces acting on the mechanism's links, leading to their deformation and possible destruction under certain operating conditions. Simulation modeling of dynamic processes in cyclic mechanisms is based on its representation in the form of interconnected typical objects, the allowable properties and limits of which are known. The article presents the dynamics study results one of the basic high-speed automatic machines mechanism in the object-oriented representation. Mechanism performs translational motion and allows the possibility of one-way kinematic connection breaking.

Nationalism and Populism as the Driving Forces of Economic Deglobalization, Regionalism, and Localism Processes

The aim of this chapter is to analyze nationalism and populism as the driving forces of economic deglobalization processes and regionalism. The analysis departs from the assumption that the economic deglobalization processes respond to more complex dynamic forces created by the economic, financial, and the most recent sanitary crisis that blocks the continuity of economic globalization. Moreover, at the center of the analysis is the conceptualization that both globalization and deglobalization are two faces of the same coin, but with opposite driving forces. These driving forces of deglobalization lead to regional and more local solutions to economic growth and social and environmental problems.

Long Term Effects of Reduced Track Tamping Works

Tamping needs to guarantee safety in limiting geometric failures in isolated points, reduce dynamic forces by a smooth through-going longitudinal level, and provide a certain riding comfort for passengers. Although different methods are applied to describe geometry deterioration, the amount of tamping needed is seldomly addressed. In this work, we evaluated and compared different tamping regimes and their long-term consequences by extrapolating the longitudinal level of track. Forecasting beyond one tamping action needs a precise positioning of measurement data and a solid methodology. We found that tracks can be operated by repairing isolated defects for more than ten years without running into technical and operational trouble, and even reducing budgets in this period. However, the long-term perspective financially shows the contrary: continuous through-going maintenance keeps track quality at a high level and provides the basis for a long service life.

VIBRATION PROCESSES AND THEIR RELATIONSHIP WITH DEFECTS

ABSTRACT The article is devoted to vibration diagnostics, an effective method for assessing the parameters of the mechanical state of centrifugal pumping units. The use of vibration diagnostics allows, due to early detection of malfunctions, to improve target operation, increase the turnaround time and reduce the likelihood of emergency destruction of pumping unit elements. Diagnostic signs of the presence of defects in various elements of the pumping unit are presented. During the development of diagnostic methods, the character stages of the development of injuries are selected. These stages are the formation of the injury, the accumulation of injuries, collapse, and so on. consists of stages. Dynamic forces are considered to be the main cause of vibration in machine parts. It is under the influence of dynamic forces that fatigue breaks down in machine parts. The use of vibrodiagnostics in machine parts allows to accurately assess the degree of damage to its individual nodes. This, in turn, leads to improved operating conditions. In conclusion, it should be noted that vibrodiagnostics not only detects malfunctions in machines, but also reveals the causes of its formation. Keywords: vibrodiagnostics, improvement of operational conditions, determination of defects, probability of emergency destruction, repair, assessment.

Shaping Frontline Practices: A Scoping Review of Human Factors Implicated in Electrical Safety Incidents

Injuries sustained while performing electrical work are a significant threat to the health and safety of workers and occur frequently. In some jurisdictions, non-fatal serious incidents have increased in recent years. Although significant work has been carried out on electrical safety from a human factor perspective, reviews of this literature are sparse. Thus, the purpose of this review is to collate and summarize human factors implicated in electrical safety events. Articles were collected from three databases (Scopus, Web of Science, and Google Scholar), using the search terms: safety, electri*, human factors, and arc flash. Titles and abstracts were screened, full-text reviews were conducted, and 18 articles were included in the final review. Quality checks were undertaken using the Mixed Methods Appraisal Tool and the Critical Appraisal Skills Program. Environmental, individual, team, organizational, and macro factors were identified in the literature as factors which shape frontline electrical worker behavior, highlighting the complexity of injury prevention. The key contributions of this paper include: (1) a holistic and integrated summary of human factors implicated in electrical safety events, (2) the application of an established theoretical model to explain dynamic forces implicated in electrical safety incidents, and (3) several practical implications and recommendations to improve electrical safety. It is recommended that this framework is used to develop and test future interventions at the individual, team, organizational, and regulator level to mitigate risk and create meaningful and sustainable change in the electrical safety space.

Review on “Assessment of the effect of lateral dynamic forces on rcc cantilever l-shaped and t-shaped retaining wall with height variations”

It is now becoming very essential to analyse the behaviour of retaining structures due to their wide infrastructural applications. The important factors which are affecting the stability of the retaining wall are the distribution of earth pressure on the wall, material of backfill & its reaction against earth pressure. There are several types of retaining walls, out of them the cantilever retaining wall is adopted for present design and study. In this paper, the study of literature based on the design of the cantilever retaining walls under seismic or dynamic conditions is studied. From the studied literature, many authors performed their calculations in Excel sheets by a manual method. Then the Results obtained from the manual calculation are then validated in STAAD pro. Several authors show the calculated quantity of steel and concrete required for various heights of walls. It is also concluded from the study that the design of cantilever retaining wall is suitable, safe, and economical up to a height of 6m, after that banding moment at toe increases. Some authors have also shown the calculated factor of safety for different height conditions. From the study of mentioned literature, we can recommended to also show the graph of bending moment with height variation. Both the designs are done for various heights ranging from 3 m to 6 m.

Structural Assessment of RCC Elevated Service Reservoir For Different Capacity

Elevated service reservoir is one of the maximum important infrastructures that is utilized by society. Our every day existence relies upon at the water supply, that is procured through an elevated service reservoir. Therefore, the safety of the service reservoir is of utmost importance. Most of the damage on elevated service reservoirs is caused by an earthquake, as the horizontal forces acting on the structure make the service reservoir vulnerable. Our predominantly study is based on extracting the dynamic forces mainly to determine critical condition of the structure. In this paper, different capacities of elevated service reservoir are taken and the design and analysis are done according to Indian standards. Dynamic analysis of the service reservoir is done and parameters such as time period, hydrodynamic pressure, base shear, base moment are compared with different capacities. Hence, the capabilities of the structure are substantially necessary to examine within the sub-continent region.

Simulation of peak tension loads in Subsea power cables during installation

At present, most of the insurance claims in the offshore wind industry are due to cable failures where a large percentage occurs during the installation of the array and export cables. As the reliability of the cables depends on the location and installation method, it is important to map the risks involved, which can compromise the cable’s integrity in individual projects. This paper presents sensitivity analyses conducted on crucial parameters in the cable laying process, with an objective of successful installation of subsea power cables without any damages to the cable. The analyses focus on the peak tension loads with reference to key parameters as cable self-weight and laying geometry, as well as the cable deployment position on the installation vessel. Finite element analyses were conducted with both static forces and dynamic forces for irregular vessel motions, by the aid of the well-tested software OrcaFlex.

Modeling the longitudinal dynamics of electric multiple units with Xcos/Scilab software

During the traction and braking of trains, substantial longitudinal dynamic forces might occur in couplers. The method of modeling these forces for two different electric multiple units (EMUs) is presented in this study. For the EMUs consisted of independent vehicles, each of which rests on two bogies, computer simulations were carried out. Simulations were also executed for EMUs with Jacobs bogies, which support bodies of two adjacent carriages. The dynamic modeling of vibration protection train systems includes nonlinearities.

Application of the soft starter for the asynchronous motor of the belt conveyor

The purpose of the work is to justify the need for a smooth start of the conveyor belt. Based on the technological features of the transportation process, the direct start of the conveyor with a loaded undercarriage entails an increase in inertial forces, overload of the traction chains and the drive. Due to the increased starting torque, there is a danger of slipping, the occurrence of an oscillatory transient of the escaping branch of the tape, slipping between the tape and the drive drum. This leads to significant wear of the tape and breakdowns of other equipment, which requires high repair costs. With a smooth start of the conveyor, the acceleration lasts longer, but the movement of the concentrated masses of the belt is more consistent, less oscillatory, which indicates less dynamic forces in the belt. Also, with a smooth start, energy losses in the engine and its heating are reduced. The main results of the work - the transients in the currents of the stator and rotor, in the speed of rotation of the motor and in the speed of movement of the conveyor belt were obtained. The developed model allows us to investigate the dynamic operating modes of the engine and the mechanical part of the conveyor, to analyze the forces arising in the belt during direct and smooth start of the conveyor, to evaluate the slip of the belt and the magnitude of the traction factor. Conclusions - the results of this work should be the basis for controlling the tension in the belt and maintaining the traction factor of the conveyor belt in the start-brake operating modes. In addition, the results obtained can be used in the development of a belt speed control system depending on the amount of random freight traffic entering the conveyor.