Dynamic Characteristics of Two-Dimensional Structures Slamming Under Free Fall Condition

doi:10.16183/j.cnki.jsjtu.2022.189

Abstract

Abstract:

The slamming process of two-dimensional structures under free fall condition with arbitrary symmetrical shapes is investigated by combining various analytical models for slamming and the precise integration method in the time domain. By closely analyzing the mathematical expression of analytical models, the total slamming force acting on the body can be decomposed into two terms which are dependent on the velocity and the acceleration respectively. The developed model proposed in this paper is validated against the results from experiments and other numerical methods. Moreover, it is found that if the gravity of body is ignored, which is a reasonable assumption for situations such as structures with light weight or large entry velocity, the maximum acceleration (or the peak slamming force) for a free fall body will always occur at the certain penetration depth for a particular shape and mass, regardless of the initial slamming velocity.

Key words: analytical model, slamming force decomposition, precise integration method, free fall

CLC Number:

U661.1

SUN Zhe, SUI Xupeng, KOROBKIN Alexander, DENG Yanzeng, ZHANG Guiyong, ZONG Zhi, JIANG Yichen. Dynamic Characteristics of Two-Dimensional Structures Slamming Under Free Fall Condition[J]. Journal of Shanghai Jiao Tong University, 2023, 57(11): 1410-1420.

Figures/Tables 10

Fig.1

Tab.1

Slamming force coefficients for different analytical models

模型	a_v₁	a_v2	a_a1	a_a2
OWM	π $c ·$ c	0	$π c 2 2$	0
WN	2 $c ·$ carcsin $c * c$	- $c 2 I 4 2$	$π 2$ c²	0
OLM	2 $c ·$ carcsin $c * c$	- $c 2 I 4 2$	$π 2$ c²	-2c
MLM	2 $c ·$ carcsin $c * c$	- $c 2 I 1 + I 2 2$	I₃+ $π 2$ c²	-2c
GWM	2 $c ·$ carcsin $c * c$ -2c^*f_y(c) $c ·$	- $c 2 I 1 + I 2 2$ +2c^*	I₃+ $π 2$ c²-c^*f(c)	0

Tab.1

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

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