Shaft Breakage Research Articles

Guidewire Entrapment During Percutaneous Intervention for Chronic Total Occlusion: A Rare Case Report

Iatrogenic complications occur in approximately 0.21% of percutaneous coronary interventions (PCI), which are critical for diagnosing and treating acute coronary syndrome. This case report details a rare complication involving guidewire entrapment during a PCI procedure for chronic total occlusion (CTO). A 71-year-old male with a diagnosis of myocardial infarction (MI) was admitted to the catheterization laboratory, where imaging revealed total occlusion of the Left Anterior Descending (LAD) artery. During the intervention, a balloon shaft breakage prevented the stent balloon from being withdrawn, necessitating an emergency surgical intervention. The guidewire was successfully removed, and urgent revascularization was performed through coronary artery bypass grafting (CABG). The patient experienced a stable recovery, being discharged after one week of intensive care unit monitoring and five days of ward observation. This case highlights the potential for severe complications in CTO interventions and suggests that pre-intervention consultation between cardiology and cardiovascular surgery teams could mitigate such risks and improve outcomes.

Manajemen Risiko terhadap Nilai Klaim Asuransi Rangka Kapal Berdasarkan ITC (Institute Time Clause) Hull 1.10.83 Clause 280 (All Risks Comprehensive) Pada Kapal BG. TRG 06

This qualitative study aims to examine the implementation of risk management in hull insurance by collecting data through interviews with the risk management staff of Asuransi Mitra Pelindung Mustika Ltd. The findings revealed that this company has applied the risk management process, including risk identification, risk analysis, risk evaluation, risk control, risk transfer through other insurance policies, monitoring, and review. The company covers losses due to fire, explosion, violent theft, piracy, accidents involving installations, collisions with aircraft or similar objects, earthquakes, volcanic eruptions, lightning strikes, accidents during loading or refuelling, boiler explosions, machinery shaft breakage, or latent defects in the machinery, hull, or frame of the insured vessel. Asuransi Mitra Pelindung Mustika Ltd. also compensates for losses due to the negligence of the captain, officers, or crew of the insured vessel, as well as the shipyard. Time to process the claim becomes a significant challenge in fulfilling the insured's rights in the claim for the BG. TRG 06 vessel because it takes up to 14 days to gather all the necessary documents. This company will cover all repair costs and labor expenses, with an estimated total value of IDR 7,611,100,000.00.

Finite Element Method Analysis of Potential Shaft Breakage in Truck Wheel Drive Due to Initial Crack

The need for truck transportation in the city of Langsa is increasing. This is because the residents of Langsa use trucks as a means of transporting palm oil from plantations. Engine component failures are often experienced in every mechanical construction, and these failures are marked by the breaking of these engine components. Cracks become one of the potential sources of failure in the machine structure. There is a need to detect cracks in the shaft at an early stage to prevent damage. Therefore, it should be investigated using appropriate techniques at the early stage of crack formation. The purpose of this research is to find the potential source of shaft fracture relative to the initial crack location on the shaft. This research method is carried out by determining the same initial crack dimensions at two different locations. The initial crack locations are determined through a case study of frequent fractures in the fillet spline and fillet flange locations. The calculation results show that the permissible stress of the shaft is 80.7 MPa. The finite element method simulation results show that the maximum shear stress value on the shaft without an initial crack is 65.234 MPa, on the shaft with an initial crack in the fillet spline location is 69.654 MPa, and on the shaft with an initial crack in the fillet flange location is 78.79 MPa. The finite element method simulation results also show that the von Mises shear stress value on the shaft without an initial crack is 113.29 MPa, on the shaft with an initial crack in the fillet spline location is 120.66 MPa, and on the shaft with an initial crack in the fillet flange location is 137.23 MPa. The finite element method simulation results further show that the von Mises shear strain value on the shaft without an initial crack is 0.000567, on the shaft with an initial crack in the fillet spline location is 0.000630, and on the shaft with an initial crack in the fillet flange location is 0.000693. In conclusion, the potential source of failure experienced by the shaft between the two locations of frequent failure is the shaft with an initial crack in the fillet flange location.

A Surge/Stall-Capable Dynamic Performance Simulation Methodology for a Turbojet Engine

Abstract A lumped-parameter dynamic performance model for a single-spool turbojet engine is presented in this paper. This model can handle pre and poststall transients under forward and reverse-flow conditions. The inter-component volume technique is employed instead of the standard matching technique to be able to handle high-frequency transients and reverse-flow conditions. Inspired by Greitzer's lumped-parameter surge model, momentum (duct) and volume elements are placed within the flow path to handle surge dynamics. Compressor and turbine maps are extended to low-flow and reverse-flow regions using a combination of the guidelines presented by Kurzke, the cubic axisymmetric characteristics of Moore and Greitzer, and a quadratic function guess for in-stall characteristics. Combustor efficiency, stability limits, and delay are taken from the literature. Poststall behavior of the model is validated using the data available in the literature for a Rolls-Royce Viper engine. A good match is observed with a correct prediction of poststall behaviors, which transition from surge after locked stall to multiple surge cycles around 80% speed and multiple surge cycles to surge after flameout around 95% speed. The effects of different modeling choices and modeling parameters on the obtained results are discussed. The produced model can be calibrated for a specific engine with surge tests, and it can be used for hard-to-test scenarios like surge after shaft breakage. Different surge/stall-causing events, such as fuel spiking, in-bleeding, and shaft breakage, are simulated to see the capabilities of the model.

Исследование износостойких покрытий, нанесенных на образцы из конструкционной стали, применяемой для изготовления валов валопровода судов на подводных крыльях

Effective interaction of structural elements and materials from which they are made is one of the most important tasks in the design of parts and mechanisms of ship power plants. The operating experience of Meteor-type vessels has shown that the main cause of propeller shaft breakage and failure may be non-compliance with the technical requirements for the chemical-thermal processing of the shaft necks to the bearings size or poor-quality superficial coating. There has been made a comparative analysis of coating technologies, its results will significantly increase the cyclic wear resistance of the surface layer of the shaft necks of the hydrofoil ship shafting. The technologies of gas-plasma and gas-dynamic spraying, as well as electrospark alloying of the surface are considered. An instrumental assessment of the parameters of the applied protective coating quality is performed. Alloying materials for each of the methods of the surface hardening and modification are also presented. The scheme and design of the stand for testing the applied coatings for cyclic fatigue strength up to the moment of critical failure are given. The coatings deposited on the samples surfaces are studied to assess the surface microgeometry and microhardness. The samples are tested on the stand with a cyclic load at an induction motor shaft speed of 1800 rpm (30 rps). A bearing ball made of steel is used as an indenter. After testing, the focus of the coating destruction is assessed visually using a measuring and computing complex based on an optical microscope. As a result of the tests, it is revealed that the samples processed by the electrospark alloying method have the highest resistance to alternating cyclic effects, the lowest surface roughness and the highest microhardness.

Research on Dynamic Pile-Driving Formula Parameters and Driving Feasibility of Extra-Long PHC Pipe Piles

Prestressed high-strength concrete (PHC) pipe pile has the advantages of high single pile bearing capacity, a wide range of applications, good driving resistance, fast construction speed, etc. It has been widely used in high-rise buildings, bridges, ports, and other industries. The application of extra-long PHC pipe piles with a length of more than 50 m is increasing. However, there are few studies on the drivability and hammering criteria of extra-long PHC piles. To analyze the drivability of extra-long piles and predict their bearing capacity, in this paper, high-strain dynamic tests were carried out on 14 test sections with the pile foundation of Temburong Bridge in Brunei as the research background. The hammer stop control criteria calculated according to the Hiley formula would lead to excessive hammering. Three types of damage occurred during construction: pile shaft breakage, weld tearing, and pile head breakage. The weight and drop height of the piling hammer selected for this project were appropriate, and the extra-long test piles can be hammered to the design depth. The values of Cp (Compression of the pile) and n (the efficiency of the blow) were fitted based on the dynamic test data, which provided a more accurate reference for the selection of subsequent piling parameters of the project. It provides a more accurate calculation method for predicting the bearing capacity of extra-long PHC piles and provides control criteria for pile stopping and a scientific basis for their design and construction.

Improved dynamic kernelPCAbased on local preserving projections and its application for electric submersible pump fault diagnosis

AbstractDynamic kernel principal component analysis (DKPCA) has been frequently implemented for nonlinear and dynamic process monitoring of complex industrial processes. However, traditional DKPCA focuses only on the global structural analysis of data sets and strongly neglects the local information, which is equally essential for process detection and identification. In this paper, an improved DKPCA, referred to as the local DKPCA (LDKPCA), is proposed based on local preserving projections (LPP) for nonlinear dynamic process fault diagnosis. The method combines the advantages of LPP and DKPCA by utilizing the local structure feature to maintain the geometric structure of the data in a unified framework. To achieve a highly comprehensive feature extraction, the local characteristics are fused in DKPCA to produce an optimization objective. The neighbouring points of the new objective function projection in the feature space are still maintained in proximity, and the variance information is retained simultaneously. For the purpose of fault detection, two statistics, known as theT2and squared prediction error (SPE) statistics, are constructed, based on the LDKPCA model, and used to monitor the latent variable space and the residual space, respectively. In addition, the sensitivity analysis is brought in for fault identification of the two statistics. Based on the experimental analysis using the shaft breakage data of an offshore oilfield electric submersible pump (ESP), the proposed method outperforms the conventional DKPCA in terms of fault monitoring performance. The experimental results demonstrate the potential of the method in nonlinear dynamic process fault diagnosis.

Fault Diagnosis Method and Application of ESP Well Based on SPC Rules and Real-Time Data Fusion

Aiming at the popularization and application of a real-time monitoring parameter acquisition system of the electric submersible pump (ESP) well, this paper proposes a fault diagnosis method of ESP well operation based on the SPC rule and prior knowledge fusion. Based on the study of parameter variation rules of ESP well, the SPC expansion rule model is established; by analyzing the variation of some typical characteristic parameters of ESP well, combined with SPC expansion rules and expert experience, a priori knowledge of fault diagnosis of ESP well is formed, that is, multiparameter fault analysis table and weight factor; the SPC extended rule model and prior knowledge are fused to establish the fault probability model of ESP well, form the fault diagnosis method of ESP well, develop the online fault diagnosis software of ESP well, and deploy it in 425 ESP wells in a block. Taking five types of tubing leakage, pump wear, shaft breakage, gas influence, and pump plugging as examples, the application process of fault diagnosis method is analyzed. The research and application show that compared with other fault diagnosis methods, this method needs a smaller time window and higher diagnosis accuracy. By setting multiple time windows, this diagnosis method is applied to calculate the fault probability of ESP well in real time, solve the real time and accurate identification of 14 sudden faults and gradual faults, and significantly improve the intelligent diagnosis level of production faults of ESP well.

Kinking and shaft breakage of a 2.6-Fr Tornus catheter during percutaneous coronary intervention for a chronic total occlusion lesion of a tortuous and calcified right coronary artery.

Kinking and shaft breakage of a 2.6-Fr Tornus catheter during percutaneous coronary intervention for a chronic total occlusion lesion of a tortuous and calcified right coronary artery.

The Safety and Efficacy of Guidezilla Catheter (Mother-in-Child Catheter) in Complex Coronary Interventions: An Observational Study.

BackgroundLesion characteristics (anatomy, calcification, tortuosity and angulation), vessel morphology, and lack of support add complexity of coronary intervention. Guidezilla catheter, acting as an extension of guide catheter system (mother-in-child catheter), helps to overcome these complexities by enhancing backup during complex intervention.MethodsThe present retrospective, single-center study included 13,157 consecutive patients who underwent percutaneous coronary intervention (PCI) through both transfemoral and transradial routes from January 2015 to July 2019 at LPS Institute of Cardiology, G.S.V.M. Medical College, Kanpur, Uttar Pradesh, India among which Guidezilla™ catheter (Boston Scientific, Natick, MA, USA) was used in 156 patients. Study endpoints were target lesion crossing, procedural success, and complications. The clinical, angiographic and procedural data of all 156 patients were evaluated to assess safety and efficacy of Guidezilla extension catheter (GEC).ResultsThe mean age of the enrolled patients was 61.2 ± 8.67 years. Type-C lesion was commonest (69.9%) followed by B2 (22.4%) and B1 (7.7%). The commonest indication for its use was tortuosity (30.1%) followed by calcification (21.1%), angulation (18.8%), chronic total occlusion (17.9%), distally located lesion (8.3%), and anomalous origin of vessel in 3.8%. The right coronary artery (39.2%) was most commonly intervened artery followed by left anterior descending (LAD) (30.8%), left circumflex (LCX) (19.9%), multivessels (7.6%), and saphenous vein graft in 2.5%. The mean depth of intubation was 4.2 ± 1.9 cm. Mean diameter of stents was 34.2 ± 14.4 mm while mean length of stents was 31.2 ± 10.2 mm. Lesions were modified using aggressive pre-dilatation in 87.8%, followed by cutting balloon in 10.9%. GEC was delivered across the lesion using buddy wire technique (9.6%), balloon-assisted tracking (BAT) in 30.1%, and balloon-assisted sliding and tracking (BLAST) in 4.5% of patients. Stent implantation was successful in 151 out of 156 patients with success rate of 96.7%. Overall failure rate was 3.3% which was contributed by extreme tortuosity, angulation, and severe calcification. Guidezilla-associated procedural complication (dissection, stent dislodgement, shaft breakage) were reported in three patients (1.9%) who were successfully managed.Conclusions Guidezilla system acting as mother-in-child extension catheter is a safe and effective tool which provides additional backup support and increases success rate of PCI for complex coronary lesions.

운전금지 구역 통과 시 선박용 중간축의 피로강도와 수명

Recent innovations on low-speed two-stroke ship propulsion engines include higher power rating with lower nominal engine speed for increased propeller efficiency and reduced fuel consumption. Additionally, 5~6 cylinder engines are preferred for having reduced dimension freeing up cargo spaces and lower repair and maintenance costs as well. Likewise, the barred speed range (BSR) protects the shafting system from increased torsional vibration stresses by passing in a shortest possible time at this critical speed. Considering above-mentioned engine specifications, shaft breakage accidents can occur from the accumulated fatigue stress due to the prolonged barred speed range passing and shafting design. This paper evaluates the propulsion shafting system fatigue strength and lifecycle of a 6G70ME model engine through theoretical analysis and torsional vibration measurement data.

5-Bromo-2'-deoxyuridine induced effluvium via p53-mediated CD326-positive keratinocyte apoptosis in C57BL/6 mice.

Anagen effluvium develops because of disturbances in the hair follicle cycle, leading to acute and severe hair loss in humans. The objective of this study was to establish a mouse model of anagen effluvium by 5-bromo-2'-deoxyuridine (BrdU) treatment, and evaluate the pathological changes and underlying mechanisms. We treated 9-10-day-old pups and 3-7-week-old C57BL/6 mice with BrdU. After successfully inducing hair loss in the neonatal pups, microscopic, immunohistochemical and flow cytometry analyses were conducted. BrdU induced early onset alopecia in neonates and caused epidermal thickening and hair shaft breakage. BrdU appeared to incorporate the CD326-positive keratinocyte layer and induced p53-related apoptosis. Keratinocyte apoptosis caused immune cell infiltration in the dermal region; M2 macrophages and neutrophils were dominant. The BrdU-induced hair loss was dose-dependent, and alopecia was visible at a dose range of 25-200 μg/g bodyweight. The BrdU-induced anagen effluvium mouse model is novel and easily established by administrating four simple BrdU injections to pups; these mice showed synchronized onset of alopecia symptoms with little individual variation. Moreover, this model showed an alopecia phenotype similar to that of human anagen effluvium with acute, severe and widespread hair loss.

Metallurgical Characterization of the Failed Motor Shaft Component from an Electric Surgical Motor used in Orthopedic Surgery

The paper presents the results of research conducted to determine the causes that led to the fracture of a motor shaft component from an electric surgical motor used in orthopedic surgery.The chemical and structural analysis emphasized a structure rich in complex silicate and sulfides inclusions. They form areas of weakness, acting like stress concentrators which induce fatigue shaft breakage. Their high density and non-uniform shape and distribution suggest a non-adequate technology of making and casting of steel, destinated to work in difficult conditions and having an important operational role.

Corrective Solutions for the Shaft with Flange Used for Fixing the Blade on a 5 kW Wind Turbine to Withstand Extreme Weather Conditions

The paper presents a case study on the original solution of a flange shaft as part of the root area of a 5 kW wind turbine blade. There were analyzed the causes that led to the shaft breakage under wind loadings in extreme weather conditions, and consequently technical solutions have been searched in order to improve the shaft design making it more reliable as mechanical strength at extreme wind loadings. The flange shaft is a welded subassembly that keeps the blades attached to the rotor hub. The first part of the paper consists in an analysis referring the loading status, the materials used for blade manufacturing, the identification of critical areas where the breaking was initiated and also the causes for which the materials assumed and specified in the technical design and manufacturing technology failed under loading at wind gusts of about 30 m/sec. Based on this preliminary analysis, the second part of the paper presents the technical solutions which were considered in reference to the materials and the improved design concept aiming to provide the right mechanical strength necessary to withstand specific wind loadings in extreme weather conditions.

Shaft crack diagnostics in a gearbox

Shaft breakage is one of the most catastrophic failures in any transmission system that can ultimately lead to significant financial loss. Although advances in shaft design have lead to improvements in endurance life, shaft failures are still common today. This paper presents an experimental investigation in which several technologies such as Acoustic Emission, vibration and motor current signature analysis, were applied to identify the presence of a naturally fatigued pinion shaft in an operating gearbox. It was concluded that the combination of these methods could offer good diagnostic information though successful diagnosis is very dependent on the diagnostic path taken by the investigator.

Observations of a naturally degrading slow-speed shaft

Acoustic emission (AE) technology applied to condition monitoring is gaining acceptance as a useful monitoring tool. This study presents an experimental investigation for incipient fault detection of low-speed shafts with the AE technology. In addition to continuous AE measurements, traditional AE parameters, the energy index, kurtosis, information entropy and Kolmogorov–Smirnov test were employed to detect and monitor natural defect initiation and propagation in slow-speed rotating shafts. A low-speed test-rig was employed to accelerate natural shaft breakage. Throughout the life of the shaft, AE measurements were acquired. It is concluded that crack initiation and subsequent fracture can be detected using a range of data analysis techniques on AEs generated from natural degrading shafts.

Multistage Compressor and Turbine Modeling for the Prediction of the Maximum Turbine Speed Resulting From Shaft Breakage

A mathematical model for the prediction of the maximum speed of a high pressure turbine following a shaft failure event was developed. The model predicts the high pressure compressor and ducting system pre- and poststall behaviors such as rotating stall and surge after the shaft breakage. The corresponding time-dependent high pressure turbine inlet conditions are used to calculate the turbine maximum speed, taking into account friction and blade and vane tip clearance variations as a result of the rearward movement of the turbine and destruction of the turbine blading. The compressor and ducting system is modeled by a one-dimensional, stage-by-stage approach. The approach uses a finite-difference numerical technique to solve the nonlinear system of equations for continuity, momentum, and energy including source terms for the compressible flow through inlet ducting, compressor, and combustor. The compressor blade forces and shaft work are provided by a set of quasisteady state stage characteristics being valid for prestall and poststall operations. The maximum turbine speed is calculated from a thermodynamic turbine stand-alone model, derived from a performance synthesis program. Friction and blade and vane tip clearance variations are determined iteratively from graphical data depending on the axial rearward movement of the turbine. The compressor and ducting system model was validated in prestall and poststall operation modes with measured high pressure compressor data of a modern two-shaft engine. The turbine model was validated with measured intermediate pressure shaft failure data of a three-shaft engine. The shaft failure model was applied on a modern two-shaft engine. The model was used to carry out a sensitivity study to demonstrate the impact of control system reactions on the resulting maximum high pressure turbine speed following a shaft failure event.

Architectural Changes in the Gill Morphology of the Freshwater Fish,Esomus danricusas Potential Biomarkers of Copper Toxicity Using Automated Video Tracking System

Biomarker responses at the histological level to xenobiotics are gaining a priority research interest. The 96h LC50 of copper sulfate to Esomus danricus is found to be 5.5 mg/L and its toxic effects on fish gills are critically examined in situ. Gills (pair III) of fish exposed to 5.5 mg/L and 0.55 mg/L of copper sulfate and control without toxicant were placed in normal saline medium and, after rinsing, placed on a glass slide and observed under a Polyvar, Reichert-Jung light microscope attached to Ethovision-version 2.3 (Noldus Information Technology, Netherlands) through a Sony CCD IRIS camera (Model No: SSC-M370CE). Damage to secondary gill lamellae with loss of shape, necrosis, clubbing and fusion, shaft breakage, atrophy, curvature of tips, thick mucous sheathing and degeneration of rakers are observed in fish exposed to 5.5 mg/L of copper sulfate. Primary and secondary gill lamellae are affected with loss of original shape, loss of alignment in rakers with hyper secretion of mucous in fish exposed ...

Performance for End Mills Made of Different Tool Materials with Regards to Tool Life and Stability

End milling operations are mostly used to machine parts of complicated shape in aerospace and turbomachine industries, where machine cost/hour is quite high for Multi-axes NC machines. This requires higher cutting speeds to economically utilize the machine tools and very often use of HSS cutters limits the metal removal rate due to low cutting speeds of HSS tools. Futhermore, cutting tool deflection and forced vibration due to impact farces in end milling are severe limitations, often resulting in surface and form imperfections. End milling cutters are made of either conventional and PM high speed steel or of Solid Cemented Carbides. Conventional HSS cutters are today widely used for all types of end milling operations. But it has been found in this study that the use of solid CC end mills attenuates both the tool vibrations and static deflection and at the same time allows a higher metal removal rate. Tool life and stability study of end milling cutters of two different tool materials. High Speed Steel and Cemented Carbide has been carried out showing that solid CC end milling cutters with diameter approximately above 12 mm can economically be utilized for machining tougher work materials. Although the solid CC end mills with diameter below 8 mm may have a better performance with regards to tool bending and tool vibrations, they are very often susceptible to cutting edge and cutting shaft breakage.

The inhalation toxicity of phenylglycidyl ether. I. 90-day inhalation study

Male and female rats and male dogs were exposed 6 hr/day, 5 days/week for 90 days (63 exposures) to atmospheres of 1, 5, and 12 ppm (v/v) of phenylglycidyl ether (PGE) vapors generated from liquid heated to a polymer process temperature of 310°C. The only significant finding was patchy, bilateral, hair loss in both male and female rats exposed at the two highest levels. Dogs did not show this effect. Histopathologic evaluation of the hair loss areas showed varying degrees of damage to the hair follicles with occasional shaft breakage outside the epidermis. Microscopic comparison of 32 other major organs and tissues from test and control animals showed no compound-related effects. Likewise, no differences between test and control groups were seen relative to body weight, hematologic, urinanalytical, or biochemical indices. The hair loss was probably attributable to a mild focal skin irritation from PGE vapor and not to a systemic effect of inhaled PGE. Our results agree with those of previous investigators in that the main hazard to workers from PGE vapor is dermal irritation. These results also suggest that the present TLV of 10 ppm (v/v) may not assure an adequate margin of protection against potential skin irritation.