Development of a Pre-Evaluation and Health Monitoring System for FAST Cable-Net Structure

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is one of China’s major pieces of national infrastructure. A variable cable-net structure is used as the main supporting structure of the active reflector. The displacement of the cable net works through actuators. The realization of linkage control is a multi-degree-of-freedom and complex coupling control system. Due to factors such as the temperature difference between day and night, as well as actuator failure, the reflector control accuracy and even structural safety are affected during the position-control process of the cable net, so realizing evaluation of control accuracy and fault warning of the reflector is a significant problem. This paper proposes a pre-evaluation and health monitoring system based on advanced mechanical simulation technology. Through this system, on-site staff can expeditiously analyze the model to determine whether the cable net is currently in a safe state, predict the fatigue degree of the components, and maintain the structure when appropriate. The pre-evaluation and health monitoring system adequately ensure the stable functioning of the FAST cable net, improve the efficiency of on-site maintenance work, and markedly reduce the safety risk of the structure.

JUSTIFICATION OF FILLERS USING IN THE BEARING STRUCTURES COMPONENTS OF FREIGHT CARS

To reduce the load on the freight cars frames under operational conditions, it has been suggested that to use fillers in their components. Fillers using is advisable in the most loaded elements of the bearing structure, namely, the spine beam. Therefore, a necessary condition for filler using in the spine beam is the creation of its closed structure. The dynamic load of railcars was carried out, taking into account the proposed provisions. Calculations have shown with filler using, the maximum accelerations acting on the bearing structures of wagons are 4% lower than those accelerations obtained for bearing structures without fillers. The results of determining the main strength indicators of bearing structures of freight cars are presented, taking into account the fillers using in their components. It has been established that the strength of the frames of the considered types of wagons under the main operating conditions is ensured. At the same time, the maximum equivalent stresses in the bearing structures of wagons are 4-9% lower than those in typical frame structures. The conducted research will contribute to the creation of innovative structures of rolling stock and reduce the cost of its maintenance work in operation.

Deciding a Multicriteria Decision-Making (MCDM) Method to Prioritize Maintenance Work Orders of Hydroelectric Power Plants

The current global competitive scenario and the increase in complexity and automation of equipment and systems demand better results from maintenance management in organizations. As maintenance resources are limited, prioritizing maintenance activities is essential to allocate them properly and to meet maintenance management objectives. In the face of these challenges, multicriteria decision-making (MCDM) methods are commonly used in organizations to support decision-making. Nevertheless, selecting a suitable MCDM method for maintenance planning can be complicated given the diversity of methods and their strengths and weaknesses. In this context, this paper proposes a novel knowledge-based method for deciding a multicriteria decision-making (MCDM) method to prioritize maintenance work orders of hydroelectric plants. As the main novel contribution, it translates the intrinsic characteristics of the main MCDM methods into questions related to maintenance planning to guide the recommendation of a suitable MCDM method for organizations through a decision tree diagram. This approach was applied to a maintenance case study of a hydroelectric power plant in order to demonstrate its use and contribute to its understanding. These findings contribute to maintenance management in selecting an MCDM method aligned with the context of its maintenance planning for the prioritization of maintenance work orders.

The Impact of Temporary Means of Access on Buildings Envelope’s Maintenance Costs

Accessibility to buildings’ envelope depends on efficient inspection and other maintenance actions of their components. When access to these components is not planned, special means of access are required to carry out the maintenance work. Means of access, besides having a fundamental role on the quality of maintenance works of building envelope components, also represents a considerable part of the maintenance costs. Thus, to optimize costs and resources in maintenance plans, assessment of the impact of the means of access on maintenance costs is crucial. For works in height, there are several alternative means of access. The choice of the most adequate solution is strongly linked to the characteristics (e.g., architecture, height) and constraints (e.g., users, surrounding space) of each building, the maintenance needs of the envelope, and the time and funds available for the intervention. Therefore, in this study, a sensitivity analysis to understand how the cost of means of access can influence the maintenance costs is carried out. Moreover, the optimisation of maintenance activities in façade claddings is also analysed. This study intends to assess whether it is advantageous to consider permanent means of access during the design phase or opt for temporary means of access. In a first stage, the impact of six temporary means of access (supported and suspended scaffolds; articulated booms; telescopic booms; scissor lifts; and rope access) on the maintenance plans developed for the six types of claddings (ceramic tiling systems—CTS, natural stone claddings—NSC, rendered façades—RF, painted surfaces—PS, external thermal insulation composite systems—ETICS, and architectural concrete façades—ACF) is examined. The impact is estimated through a stochastic maintenance model based on Petri nets. After that, a sensitivity analysis and a multi-criteria decision analysis are performed. Based on the results, general recommendations are presented concerning the maintenance strategies to adopt in the cladding solutions analysed. The results reveal that planning the means of access during the design stage can be economically beneficial for all buildings’ envelope components.

Tile drainage monitoring in agricultural fields with an unmanned aerial system

In Russia, the volume of restoration and maintenance work of drainage reclamation systems has significantly decreased, the number of trained reclamation specialists has decreased, most of the objects need reconstruction, and the documentation and schemes of pipes and channels of drainage systems have been lost. Accordingly, the development of agricultural drainage reclamation will require large amounts of financial and labor costs. The aim of the work is to present an alternative approach to assessing the status of these systems for making management decisions using an unmanned aerial system (UAS), which allows you to quickly obtain high quality aerial photographs (2-7 cm/pixel) of an agricultural area up to 50 hectares in one flight. In addition to the unmanned aerial vehicle, the UAS also includes an onboard complex, a payload and a ground control station. The flight group carries out all stages of data acquisition and preprocessing in an automated mode using specialized software. In the course of the experimental studies, the main elements of the considered approach to monitoring drainage systems are highlighted: the period of aerial photography, determination of the pipes and canals schemes, determination of waterlogging zones on agricultural areas and breakdowns of a reclamation system, monitoring in dynamics. As a result, when solving the problem of monitoring drainage reclamation systems, the use of UAS seems to be a relevant and promising approach, which makes it possible to assess the object status promptly.

Developing a Conceptual Model for Strategic Knowledge Sharing of Facilities Management Protocol (FMP)

The aim of this paper is to identify a key dimension of knowledge sharing strategy to improve Facilities Management Process of Protocol (FMP) in achieving facilities management organization performance. It investigates the key dimension of facilities management protocol strategy that can be adopted by the Facilities Management organizations and examines the problem related to IBS during the operational stages of maintenance management. An analysis of previous research provides an insight of the relationship between the IBS attribute and Facilities Management Protocol (FMP) component that can proposed a significant variable to improve the FM performance to solve problem related maintenance for IBS building. The review shows that a factor related to FM Protocol such as ‘operate and optimize facility’, ‘monitor and record facility condition’, ‘implement schedule maintenance work’, ‘manage inventory and spare part’, and ‘supervised vendor work’ was identified as a key dimension for FMP strategy to improve FM performance. Meanwhile a factor such as ‘diagnosing tools and assessment’, ‘systematic procurement procedure’, ‘complementary IBS input and information document’ and ‘handing over document’ was classified as a key factor to improve FM performance through adopting knowledge sharing strategy. This paper suggests that through improvement of each factor, the recognition of the whole strategic approach process in FMP can be increase thus helping to strengthen the facilities management organization for competitive advantages.

Effects of basal clearance on the impact dynamics of dry granular flow against dual rigid barriers

A basal clearance is usually designed beneath barriers to enable sufficient discharge to minimise the maintenance work over service life. Current design guidelines for multiple barriers usually neglect the influence of basal clearance, resulting in either an over-conservative or a non-conservative design impact force acting on the subsequent barriers. In this study, physical model tests were carried out to investigate the effects of basal clearance height (Hc) beneath first barrier on the interaction between dry granular flow and dual rigid barriers. A new approach based on the hydrodynamic equation is proposed to estimate the impact force on the second barrier exerted by the basal discharge from the first barrier. This basal discharge can attenuate the impact force exerted on the second barrier by dissipating the kinetic energy of landing flow and apportioning the load contributions from discharge and overflow. For the first barrier with a barrier height HB1 that was twice of the flow depth h0, the impact force on the second barrier was governed by overflow when Hc/h0 ≤ 0.6 and was dominated by basal discharge when Hc/h0 ≥ 0.8. These two criteria provide a basis for optimising the impact forces for multiple-barrier systems with basal clearances.

Family-Related Determinants and Implications of Low Female Enrolment in Electrical Trade in Adamawa State

Purpose: This study examined the perceived family-related determinants and implications of the low enrolment of female students in electrical installation and maintenance works in government science technical colleges of Adamawa State. Approach/Methodology/Design: A descriptive survey research design was adopted for the study. The population of the study consisted of 13 Electrical Installation and Maintenance Work Trade (EIMWT) teachers and 129 parents of National Technical Certificate Two (NTCII) EIMWT students (either father or mother) in three Government Science Technical Colleges of Adamawa State. The sample of the study comprised of the entire population, thus no sampling was done. A 20-item questionnaire was developed by the researcher and used for data collection. The questionnaire was validated by three lecturers from the Department of Electrical Technology Education, Modibbo Adama University, Yola, Adamawa State. A reliability coefficient of 0.87 was obtained for the instrument using Cronbach Alpha. Mean was used to answer the research questions while a t-test was used to test the hypotheses. Findings: The findings of the study revealed low contribution from the female gender to family income in households and increased level of dependency of the female gender on the males in Adamawa State as major perceived family-related implications. Practical Implications: The study presents practical implications for concerned authorities to work on dismantling the negative perceptions about female education. The results suggest working closely with several institutions to raise awareness and enlighten parents and family members on the prospects of EIMWT, especially to the female gender. Originality/value: The study concludes that EIMWT is a way of investing in the education of females in view of breaking cycles of poverty and social vices that the females might be lured into.

Calculation of the salary and key provisions of the methodology for determining the total costs of technical service of machinery and equipment in animal husbandry

The initial data for calculating the basic salary are: the labour intensity of carrying out maintenance and repair of machinery and equipment in animal husbandry, as well as hourly tariff rates for workers in workshops and areas for the repair of agricultural machinery and tools, which are accepted directly in farms and repair and maintenance organizations independently, but not lower than the tariff rate has been established for budget organizations. The purpose of the work was to calculate the basic salary of personnel according to the tariff categories used in the Republic of Belarus, and to consider the key provisions of the methodology for determining the total costs of technical service of machinery and equipment in animal husbandry. The most important provisions of the methodology for calculating the basic salary of personnel of repair and maintenance departments and organizations operating in the livestock subcomplex of the Agro-industrial complex of the Republic of Belarus have been presented. The main points of the methodology for calculating the total costs of maintenance and repair for machines and equipment of livestock farms and complexes have been given in relation to the conditions and their own features of accounting and planning of repair and maintenance work in domestic animal husbandry. An example of practical calculation of costs for carrying out various types of maintenance and repair of a widely used domestic milking machine has been considered.