Broken Component Research Articles

Emergency Supply Alternatives for a Storage Facility of a Repairable Multi-Component System

This paper studies a continuous-review stochastic replenishment model for a multi-component system with regular and emergency orders. The system consists of N parallel and independent components, each of which has a finite life span. In addition, there is a warehouse with a limited stock of new components. Each broken component is replaced by a new component from the stock. When no component is available, an emergency supply is ordered. The stock is managed according to an ((s,S),(0,Qe)) policy, which is a combination of an (s,S) policy for the regular order and a (0,Qe) policy for the emergency order. The regular order is delivered after an exponentially distributed lead time, whereas the emergency order is delivered immediately. We study three sub-policies for emergency orders, which differ from each other in size and in relation to the regular order. Applying the results from queueing theory and phase-type properties, we derive the optimal thresholds for each sub-policy and then compare the economic benefit of each one.

InsPLAD: A Dataset and Benchmark for Power Line Asset Inspection in UAV Images

ABSTRACT Power line maintenance and inspection are essential to avoid power supply interruptions, reducing its high social and financial impacts yearly. Automating power line visual inspections remains a relevant open problem for the industry due to the lack of public real-world datasets of power line components and their various defects to foster new research. This paper introduces InsPLAD, a Power Line Asset Inspection Dataset and Benchmark containing 10,607 high-resolution Unmanned Aerial Vehicles colour images. The dataset contains 17 unique power line assets captured from real-world operating power lines. Additionally, five of those assets present six defects: four of which are corrosion, one is a broken component, and one is a bird’s nest presence. All assets were labelled according to their condition, whether normal or the defect name found on an image level. We thoroughly evaluate state-of-the-art and popular methods for three image-level computer vision tasks covered by InsPLAD: object detection, through the AP metric; defect classification, through Balanced Accuracy; and anomaly detection, through the AUROC metric. InsPLAD offers various vision challenges from uncontrolled environments, such as multi-scale objects, multi-size class instances, multiple objects per image, intra-class variation, cluttered background, distinct point-of-views, perspective distortion, occlusion, and varied lighting conditions. To the best of our knowledge, InsPLAD is the first large real-world dataset and benchmark for power line asset inspection with multiple components and defects for various computer vision tasks, with a potential impact to improve state-of-the-art methods in the field. It will be publicly available in its integrity on a repository with a thorough description. It can be found at https://github.com/andreluizbvs/InsPLAD/.

Discussion of an overview of some classical models and discussion of the signature‐based models of preventive maintenance

Discussion of an overview of some classical models and discussion of the signature‐based models of preventive maintenance

The implementation of preventive maintenance using machine damage analysis: a case study of power plant machine

Maintenance has an important role in supporting the manufacturing process. The irregular maintenance in the industry can cause downtime and discontinue the production process. The importance of maintenance can be seen in PT PLN Sektor Tello, one of the industries which supply the electricity in Makassar. Since the electricity contributes to the huge impact on the life’s sector, there should be preventive maintenance to all of the machine components in order to ensure that the components can run well and reduce the impact. To analyze the PT PLN Sektor Tello machine’s performance, the researchers use the Failure Mode and Effect Analysis (FMEA) to identify the type of failures and recommend the maintenance plan. The FMEA’s result will be used to calculate the RPN (Risk Priority Number) for each failure and provide the recommendations that will be conducted at maintenance when the RPN’s value is equal or more than 125. By using the FMEA, we found three types of machine failures, such as the component’s leakage, the machine’s knock, and the broken component.

Broken components versus broken systems: why it is systems not people that lose situation awareness

This commentary is a response to Dekker's insightful article in this issue on situation awareness (SA). This is a concept that continues to excite strong debate but only because of the profound implications for the theoretical foundations and the effects that different approaches have for the work of human factors practitioners. We argue that Dekker's paper tacitly adopts one approach to SA, and in doing so will inevitably arrive at the point of questioning the concept in its entirety. If SA really is as deterministic and `broken component' orientated as Dekker describes, then we would be in complete agreement, but instead we offer a counterpoint. We apply our distributed situation awareness approach to the key issues raised, answer all of Dekker's concerns, and offer a useful way forward.

Analysis of Independent Components for ERPs from ADHD patients of various ages

We investigated the characteristics of independent components for event-related potentials in adolescents (11- 17 years old) and adults (18-30 years old) with attention deficit hyperactivity disorder (ADHD), compared to the normative database. In both age groups was found significant decrease in the amplitude of the two independent components generated (according to sLORETA) in the left posterior temporal and premotor cortex and presumably associated with the processing of visual stimuli and the action suppression. In the teenage group, moreover, was broken component generated in the cingulate cortex in the adult group - another component, the source of which is localized in the premotor cortex.

The analysis of a damaged component from the connection system of the wagons

The operation of passenger trains in different continents is still differentiated by different wagon connections systems. The predominant wagon connection in North America and Australia is the autocoupler system. The system of draw hooks and buffers is now rare. In Europe, draw hook and buffer systems are still in wide use. In particular, the majority of passenger trains in Romania have wagons connected by draw hook and buffer systems. This paper presents an unusual situation for analysis of a damaged component of draw hook system and where has been lost the basic information about the causes of failure. Due to the lack of information, the analysis has a high degree of assumptions, being based on failure scenarios. The broken component is a link plate made of forged steel. After an initial examination of the fracture surface, was observed the existence of a structural defect in the material from which was initiated a fatigue crack. The analysis involves an experimental evaluation of the mechanical properties of the failed component material, followed by the modeling of the behavior of connection system according to the position where is mounted on the train. Based on the mode of fatigue crack propagation, correlated with the loading level of the connection system, different scenarios have been made about the time of propagation. Because important information about the failure causes was lost, the analysis was performed taking into account almost all factors that could influence the fatigue crack propagation.This analysis came in completing the expertise done by specialists in Traffic Safety on the Railways.

Fracture Characteristics of Tensional–Torsional Fatigue Failure of the Archimedes Helix

“Archimedes helix” (Fig. 1) is very widely applied in worm gear systems (Fig. 2) and is a critical component of transportation systems of raw material in the ceramic industry. Failures of such components from mineral processing plants (production of ceramics) have been addressed in our lab during the last two years. The helixes are manufactured from of ferritic–perlitic steels that are usually protected during service by a hard surface coating. In the recent years, uncoated material is progressively replacing the more expensive hard coated materials primarily for economic reasons. The uncoated material frequently fails owing to the fracture of the component into two pieces (Fig. 3). A serious economic consequence of such failures is the stoppage of the production line until the broken component is replaced, while the cost of the component itself is negligible. Failure analysis was conducted, and it revealed that the primary mechanism of fracture tensional–torsional fatigue. The use of penetrant testing–non destructive testing (PT–NDT) makes it possible, in many cases, to detect the fatigue phenomenon at its early stages and to replace the part during the normal service of the machine, thereby avoiding unexpected plant shutdown.

Immunet: Dependable Routing for Interconnection Networks with Arbitrary Topology

A complete mechanism for tolerating multiple failures in parallel computer systems, denoted as Immunet, is described in this paper. Immunet can be applied to arbitrary topologies, either regular or irregular, exhibiting in both cases graceful performance degradation. Provided that the network remains connected, Immunet is able to deal with any number of failures regardless of their spatial and temporal distribution. Our mechanism operates on the basis of a dynamic network reconfiguration in response to failures. The network reconfiguration only employs local information recorded at the router nodes which leads to a highly scalable system. In addition, its low cost and overhead permit a practicable hardware implementation. Finaly, Immunet could allow circumvent failures transparently to applications running on a parallel system because it does not require dropping in-flight traffic. Only packets stored in or traveling through a broken component should be recovered by higher system levels.

Shear-lag simulation of the progress of interfacial debonding in unidirectional composites

A shear-lag simulation was developed to describe the progress of interfacial debonding in unidirectional fiber-reinforced composites, in which the shear stress and energy release rate criteria, which assume, respectively, that the debonding occurs when the shear stress exerted at the interface and the energy release rate exceed the critical value, were used. With application of the present method to some examples, the manner in which the progress of the interfacial debonding depends on the location, number and species of broken component was revealed. The similarity and differences in the debonding process between the two criteria were also shown for some examples.

Influences of residual stresses, frictional shear stress at debonded interface and interactions among broken components on interfacial debonding in unidirectional multi-filamentary composites

In the debonding process of multi-filamentary unidirectional fiber-reinforced composites, the broken components (fiber and matrix) and debonded regions interact with each other. In this work, a new two-dimensional shear lag simulation method has been developed to investigate such interactions under the influences of the residual stresses and frictional shear stress at the debonded interface and it has been applied to obtain the outlines of the debonding process. It is shown that (1) the debonding is hastened by the interactions; (2) the existence of the frictional shear stress at debonded interface reduces the growth rate of the debonding; and (3) the existence of tensile and compressive residual stresses in the longitudinal direction in the matrix and fiber, respectively, acts to hasten the growth of the debonding when the broken component is matrix, while it acts to retard when the broken component is fiber.