ABSTRACT

The current safety assessments of lashing systems and container stacks in various classification societies are based on static conditions, while dynamic behaviours are neglected. In this paper, the dynamic mechanical behaviour of a seven-tier 20-ft ISO freight container single stack and lashing devices under the combined rolling and pitching excitation is studied respectively. Through experiments and numerical simulations, five typical lashing arrangements are compared. The results show that a reasonable configuration of lashing stiffness, twist lock gap and lashing arrangement can decrease the dynamic response of the system. The external lashing arrangement is more suitable for the heavy stowage situation. The twist lock structure is more prone to failure in the horizontal direction than in the vertical direction, and a reasonable horizontal gap can effectively prevent the shear force from exceeding the allowable value. Finally, the benefits and drawbacks of each lashing arrangement for shipping companies are discussed.

摘要

目前各船级社对绑扎系统和集装箱堆垛的安全评估都是基于静态条件，而忽略了动态行为。本文分别研究了7层20英尺ISO货运集装箱单堆捆扎装置在横摇和纵摇联合激励下的动态力学行为。通过实验和数值模拟，比较了五种典型的绑扎布置。结果表明，合理配置绑扎刚度、扭锁间隙和绑扎布置可以降低系统的动态响应。外部绑扎布置更适用于重载情况。扭锁结构在水平方向比在垂直方向更容易失效，合理的水平间隙可有效防止剪力超过允许值。最后，讨论了航运公司每种绑扎安排的利弊。