| URN | etd-0811126-091556 | Statistics | This thesis had been viewed 3 times. Download 0 times. |
| Author | CHUANG-CHI WEN | ||
| Author's Email Address | live588888li@gmail.com | ||
| Department | Institute Of Mechanical Engineering | ||
| Year | 2025 | Semester | 2 |
| Degree | Master | Type of Document | Master's Thesis |
| Language | zh-TW.Big5 Chinese | Page Count | 61 |
| Title | A Study on the Effects of Transient Impact and Vibration during Container Crane Operations | ||
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| Abstract | This study investigates the wheel¡Vrail impact induced when the wheels of port container cranes traverse rail expansion joints and evaluates the effects of different joint geometries on the mechanical response and damage of the crane travel system. Relevant studies on wheel¡Vrail impact, expansion joint design, material fatigue, and failures of crane travel systems were first reviewed and synthesized to establish the research framework. Subsequently, a simplified mechanical model of a wheel traversing a rail expansion joint was developed based on the equivalent drop-impact concept. Key parameters, including wheel load, travel speed, wheel drop displacement, and equivalent wheel¡Vrail contact stiffness, were incorporated to derive an equation for estimating the peak impact force. A geometric correction factor was further introduced to characterize the load-distribution effect of a 45¢X oblique-cut expansion joint on vertical impact loading. For the numerical analysis, finite element models of the wheel¡Vrail expansion joint system were established to compare the contact stress, equivalent stress, and impact time-history responses of 90¢X transverse-cut and 45¢X oblique-cut expansion joints under various wheel drop conditions. ¡@¡@The results indicate that when a wheel traverses a 90¢X transverse-cut expansion joint, the wheel¡Vrail contact condition changes abruptly within a short period, resulting in relatively high transient impact loads and localized stress concentrations. In contrast, the 45¢X oblique-cut configuration enables the wheel¡Vrail contact region to transfer progressively along the inclined joint, thereby extending the load-transfer and impact durations and reducing abrupt load variations and localized stress concentrations. The finite element analysis further demonstrates that, under identical wheel load, travel speed, and wheel drop displacement conditions, the contact stress, equivalent stress, and impact response associated with the 45¢X oblique-cut expansion joint are less severe than those of the 90¢X transverse-cut configuration. These findings confirm that geometric modification of the expansion joint can effectively distribute the impact load generated as the wheel traverses the joint. Furthermore, after the existing 90¢X transverse-cut rail expansion joints were replaced with 45¢X oblique-cut joints in the field, three years of operational testing and maintenance records revealed substantial reductions in bearing fractures, axle damage, and rail deterioration within the crane travel system. The frequency of abnormal component failures and the associated maintenance requirements also exhibited a decreasing trend. The field observations are consistent with the theoretical analysis and finite element simulation results, demonstrating that 45¢X oblique-cut expansion joints can effectively mitigate wheel¡Vrail impact and reduce the risk of damage to critical components of the crane travel system. ¡@¡@In conclusion, modifying the conventional 90¢X transverse-cut expansion joints of port container crane travel rails to a 45¢X oblique-cut configuration can effectively alleviate transient impact loads and stress concentrations as the wheels traverse the joints, while reducing damage to bearings, axles, and rails. The findings of this study may serve as a reference for rail expansion joint design, existing port crane system improvement, and preventive maintenance planning. The proposed configuration can enhance the operational reliability of crane travel systems, extend equipment service life, and reduce the risks and costs associated with unplanned downtime and maintenance. Keywords: container crane, rail expansion joint, oblique-cut joint, impact force |
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| Files | indicate access worldwide | ||
| Date of Defense | 2026-07-14 | Date of Submission | 2026-08-18 |