Research on the Contact Pressure Calculation Method for the Misaligned Elastomeric Journal Bearing

Zhou, Wenbin; Zhao, Yong; Yuan, Hua; Liu, Jingxi; Wang, Xiaoqiang

doi:10.3390/jmse10020141

Cited by 5 publications

(6 citation statements)

References 16 publications

(37 reference statements)

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“…In that particular case study of the shafting system of an 82000 DWT bulk carrier, the initial alignment of the vessel was compared against the performance corresponding to different bearing offset combinations. Similar studies have been recently reported by other researchers especially focusing in the important effect of hull structural deformations in regard to shaft alignment [12][13][14].…”

Section: Introduction and Literature Trendssupporting

confidence: 88%

A Pi-Theorem-Based Advanced Scaling Methodology for Similarity Assessment of Marine Shafting Systems

Rossopoulos,

Papadopoulos

2024

Preprint

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This paper introduces a rigorous and comprehensive approach for the assessment of marine shafting systems through the utilization of an advanced Pi-Theorem based scaling methodology. Integrating journal bearing similarity assessment and shaft-line scaling methodology with advanced dimensional analysis, the study aims to provide a methodology foundation for systematic replication and analysis of marine shafting systems through scaled models. The proposed scaling methodology ensures geometric and mechanical similarity in terms of shaft-line deflection, considering key scaling parameters such as shaft length, diameter, weight, loads, rotational speed, material properties, bearing locations, and offsets. The advanced dimensional analysis computes specific non-dimensional ratios to guarantee a close resemblance between a real-size system and a scaled lab model, enabling meaningful experimentation. The methodology is analytically derived and validated with numerical simulations for a case study, conducting comparative analysis, evaluating discrepancies, and utilizing the integrated framework for experimentation.

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Section: Introduction and Literature Trendssupporting

confidence: 88%

A Pi-Theorem-Based Advanced Scaling Methodology for Similarity Assessment of Marine Shafting Systems

Rossopoulos,

Papadopoulos

2024

Preprint

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“…The study found that hull deformation is a significant factor in shaft alignment and that the matrix displacement method is an effective tool for calculating hull deformation. This research provides valuable insights into the importance of considering hull deformation when aligning shafts and highlights the usefulness of the matrix displacement method in this regard [17].…”

Section: Introductionmentioning

confidence: 90%

“…The study also shows the substantial impact of hull deflection on shaft alignment in medium-sized ships [16]. Zhou et al (2023) investigated the effects of hull structural deformation on shaft alignment. The study divided hull deformation into global and local deformations and simplified them into two models: single-span and grillage beam.…”

Section: Introductionmentioning

confidence: 99%

Validation of the Hull Girder Deflection of a Multipurpose Cargo Ship

Abedin,

Franklin,

Mahmud

2024

AEJ

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When a ship encounters head-sea conditions, it can experience still water bending and wave-induced vertical moments. These moments can cause the hull girder to undergo longitudinal deflection, which can negatively impact the shaft alignment of the propulsion unit and the sealing of hatch covers and other onboard machinery. On the other hand, beam sea conditions can lead to transverse hull girder deflection, which is especially problematic for open-deck ships and can cause significant hatch-coming deflection. A numerical strength check has been performed using FEA software FEMAP with NX Nastran and an analytical review based on Euler-Bernoulli's beam theory to analyse the ship's strength. The ship is represented as a simply supported beam, and both analytical and numerical methods are used to calculate deflection for different sea conditions (head and beam seas). A mesh sensitivity analysis has been done to ensure the accuracy of the numerical analysis, and the results from both techniques are compared to validate their accuracy. Finally, a numerical analysis is conducted to confirm the accuracy of the analytical study when considering the ship as a complex structure. Overall, this research underscores the greater significance of longitudinal deflection over transverse deflection in the hull girder of a multipurpose cargo ship. Combining both approaches, a comprehensive understanding of the ship's hull girder strength and deflection behaviour is achieved, enhancing overall structural integrity and safety.

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“…[22] and Ref. [24], respectively. In the third stage, there are two pressure cases corresponding to the initial start/stop and continuous operation of the shaft system, namely static contact pressure and dynamic hydrodynamic pressure.…”

Section: Case Study Of the Effect Of Hull Deformation On Shaft Alignmentmentioning

confidence: 99%

“…Analysis of the bearing failure form demonstrates that side abrasion with an angle between the shaft and the bearing also occurs frequently. An increasing amount of research [24][25][26] has discovered that the relative angle influences the load area and pressure distribution of a single bearing significantly. As the scale of the bearing increases, it becomes inappropriate to analyze the bearing's operating condition by simplifying the bearing to a simple point and ignoring the relative position relationship between the shaft and the bearing.…”

Section: Introductionmentioning

confidence: 99%

Study of the Hull Structural Deformation Calculation Using the Matrix Displacement Method and Its Influence on the Shaft Alignment

Zhou

Zhao

Yuan

et al. 2023

JMSE

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The analysis of the influence of hull deformation on shaft alignment is predominately conducted using the finite element method (FEM), which is time-consuming, labor-intensive, and challenging to use for iterative hull design optimization. In this paper, hull deformation is separated into two parts—global deformation and local deformation, simplified to a single-span beam model and a grillage beam model, respectively—then solved using the matrix displacement method (MDM). Compared to FEM, the proposed method has a small calculation error, proving its correctness, while the calculation time is greatly reduced. The proposed method has been used to calculate the hull deformation of a ship under various conditions and evaluate its influence on shaft alignment. The results indicate that under certain conditions, the bearing reaction forces are constant, whereas the bearing pressure changes as a consequence of the change in shaft-to-bearing angle. The comparison between local rotation and shaft-to-bearing angle reveals that bearings in various positions follow distinct laws. We suggest that the shaft-to-bearing angle be used as an additional parameter in the evaluation of shaft alignment calculations. Moreover, when optimizing bearing pressure, bearings in different positions are affected differently by global and local deformation, and their optimization priorities are distinct.

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Research on the Contact Pressure Calculation Method for the Misaligned Elastomeric Journal Bearing

Cited by 5 publications

References 16 publications

A Pi-Theorem-Based Advanced Scaling Methodology for Similarity Assessment of Marine Shafting Systems

A Pi-Theorem-Based Advanced Scaling Methodology for Similarity Assessment of Marine Shafting Systems

Validation of the Hull Girder Deflection of a Multipurpose Cargo Ship

Study of the Hull Structural Deformation Calculation Using the Matrix Displacement Method and Its Influence on the Shaft Alignment

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