Experimental drop test investigation into cross deck slamming loads on a trimaran

ABSTR A C T The slamming phenomenon of the cross deck is a key problem in the structural design of trimaran. However, there is still a lack of sufficient experimental data to reveal the slamming load characteristics of the cross deck in different situations, especially the situation when the cross deck suffers water impact and the bottom of main hull does not come out of the water. In this paper, two models with different main hull shapes are designed to investigate slamming loads of different slamming scenario. One model has the main hull which is similar to the original trimaran section, and the other model has a lengthened main hull to avoid the obvious separated jet from the bottom of main hull. The free-fall drop tests of the two models were conducted, and the test system shows good stability. By comparatively investigating the flow field and the impact pressure of the two models during the water entry, it is found that the cross deck slamming pressure coefficient of the model with the original main hull is obviously smaller than that with the lengthened main hull due to the disturbance of bottom slamming on the flow field.