Nonlinear Response of Four-Tier Container Multiple Stacks with Different Lashing Approach Under Dynamic Excitation

This study delves into the nonlinear dynamic response of four-tier dual stacks subjected to dynamic excitation and employs internal and external lashing methods to identify causes of container damage and lashing failure. Researchers constructed a scaled model based on Froude scaling laws and used a shaking table to simulate the dynamic excitation. By integrating numerical simulations with model experiments, the study systematically analyzed the displacement and acceleration responses of the container stacks, with particular focus on nonlinear factors such as sliding and collision. The results reveal that exceeding specific critical points in excitation amplitude and frequency leads to the gradual overcoming of friction between adjacent container corner castings, resulting in noticeable relative sliding and collision. Twist lock gaps significantly worsen collision behavior, highlighting their critical impact on the stacking system’s nonlinear collision dynamics. Additionally, under conditions of high-amplitude and high-frequency excitation, external lashing schemes proved more stable and resistant to collisions than internal ones. The study also emphasizes that collisions between adjacent stacks can trigger load redistribution, thereby altering the stack’s load transfer path and impacting the stability of the entire stacking and lashing system.