Modeling and analysis of dynamic load factor in a fail-safe crane mechanism equipped with a hydraulic equalizing cylinder

• Published in: Results in engineering 2023-03, Vol.17, p.101009, Article 101009
• Main Authors: Ghasemi, Amirehsan, Ghasemi, Arash, Goulet, Ronald, Newman, James C., Ray, Gregory Mark, Bacon, Barry Brookes
• Format: Article
• Language: English
• Subjects: Dynamic load factor; Hydraulic equalizing cylinder; O-ring; Orifice; Overhead crane; Single-failure-proof crane
• ISSN: 2590-1230; 2590-1230
• DOI: 10.1016/j.rineng.2023.101009

In the design and manufacturing of sensitive crane mechanisms, in particular, those utilized in nuclear facilities, safety is of utmost importance. A few designs are based on a hydraulic equalizing cylinder where the purpose is mainly to dampen the dynamic load factor generated by the sudden failure of the wire rope system. To the best of the authors' knowledge, design equations and engineering models for such an intricate dynamic mechanism are not reported anywhere in the literature. Toward achieving this goal, a model is proposed for the dynamic behavior of a hydraulic equalizing cylinder when coupled to a single-failure-proof cross-reeved crane hoist. The constitutive equations involve the time-dependent incompressible Navier-Stokes equations. These equations are coupled with the dynamics of the lower block and the elastic wire rope. A nonlinear second-order ordinary differential equation is obtained, which is solved analytically. This yields a closed-form relation for the dynamic load factor. The validity of the new model is investigated using experimental studies, which are presented in this work. The normalized root mean square error for the dynamic load factor obtained by the model compares favorably to the experimental results, where the maximum observed error is 3.9 percent. The results confirm that the current model can be used as a design equation by practitioners. •Theoretical relations of a hydraulic cylinder coupled to a single-failure-proof cross-reeved crane hoist are developed.•The most important parameter affecting the Dynamic Load Factor (DLF) is revealed to be the orifice diameter.•An experimental setup is presented to probe the DLF under various loading scenarios.•The average discrepancy between theory and experimental results is between 0.2 and 3.55 percent.•Experimental results revealed that the current theoretical results are valid for the orifice diameter smaller than 2 mm.