Time History Response of A Large Floating Structure Subjected to Dynamic Load

Abstract

The concern of the paper is the transient behaviors of a VLFS (Very Large Floating Structure) subjected to dynamic load induced by airplane landing/taking-off. A series of weight dropping test and a series of car running test have been carried out in SRI using a scale model, VL-10, which was designed similar to the Mega-float prototype VLFS. These kinds of dynamic behavior are regarded as most essential phenomena in airplane landing/taking-off. Elastic response of the structure to vertical or horizontal transient load has been investigated through experiments and calculations, then the characteristics of the behavior of VLFS will be discussed focussing on the hydroelastic effects. A time-domain analysis method which can be applicable to the hydroelasticity problems for VLFS has been developed. The method is based on FEM scheme to treat structure and Wilson's 6 method to pursuit time step procedure taking advantage of the memory effect function for hydrodynamic effects. The present calculation method has been applied to the analysis of the tests. The effectiveness of the method has been verified through comparing the calculated results with the tests. 1. •• OEû 'åOE^ •‚ 'Ì ‚Ì 'e •« ‰ž "š ‚ɂ‚¢ ‚Ä‚Í •Aƒ• ƒKƒt ƒ••[ ƒg‹Z •p OE¤ ‹ †'g • ‡ ‚Ì "-'« ‚ðˆø‚ðˆø ‚« ‹à ‚AE‚µ‚Ä•A‚± ‚Ì •" "NŠÔ‚É'½•" ‚Ì ŽÀ OE± "I‚¨‚ae‚щðI‚¨‚ae‚щð •Í "I OE¤‹ † ‚ª ‚È ‚³ ‚ê 'å ‚« ‚È•i "W‚ª ‚Ý ‚ç‚ê ‚½ •B"Á‚É •A"g˜Q' † 'e•« ‰ž "š ‚Ì OE¤ ‹ † ‚ɂ‚¢ ‚Ä‚Í •A'å •¼1)‚â ‰i "c2) ‚ͤ•]-ˆ •¢ "ï ‚AE‚³ ‚ê ‚Ä‚« ‚½4,000•`5,000m‚Ì '· ‚³ ‚ð-L ‚· ‚é'´ 'å OE^ •‚ 'Ì(VLFS)‚É "K-p ‚Å‚« ‚é ‰ð •Í-@‚ð ŠJ"-‚µ•A‹»-¡ ‚ ‚éOE‹‰Ê ‚ðŽ¦ ‚µ‚Ä‚¢ ‚é•B 'åOE^ •‚ 'Ì ‚É•ì-p ‚· ‚é ŠO-Í‚AE‚µ ‚Ä‚Í •A"g ˜Q‰× •d ‚ð•‰‚ß ‚AE ‚µ‚ÄOEW-¯-Í ‚â •q ‹ó ‹@‚Ì-£ "-'…Žž‚Ì •ÕOE‚‰× •d ‚â •… •½ˆÚ "® ‰× •d ‚³ ‚ç ‚É-Ž ‰º •¨ 'Ì ‚É‚ae‚é •Õ"Ë‚È ‚Ç-l•X‚È"®"I ‰× •d ‚ª •l ‚¦ ‚ç‚ê ‚é•B ‚±‚ê ‚ç ‚Ì ŠO-Í ‚͈ê‚͈ê"Ê"I ‚É‚Í ‹K'¥ "g ‚Ì ‚ae ‚¤‚ÈŽüŠú"I ‚È ‚à ‚Ì ‚AE ‚Í OEÀ ‚炸•‚炸•A‚Þ ‚µ ‚ë •s ‹K'¥ ‚È‰ß "n"I ‚È•ê • ‡ ‚Ì •û ‚ªˆê‚ªˆê "Ê"I ‚Å‚ ‚é•B •] ‚Á‚Ä‚±‚ê ‚ç ‚Ì ‰ß "n "I ‚È OE» •Û‚É'Î ‚· ‚é•\ '¢ •¨ ‚Ì ‰ž "š ‚ð 'm ‚è•A-v ‹• •« "\ ‚ð •Ý'è ‚· ‚é ‚± ‚AE‚Í •ÝOEv •ã •d-v ‚Å‚ ‚é•B ‚µ‚©‚é ‚É•A‚±‚ê ‚ç ‚Ì ‰ß "n"I ŠO-Í‚É'Î ‚· ‚é'e •« ‰ž "š ‚É ‚‚¢ ‚Ä‚Í •A‚±‚ê ‚Ü‚ÅŽÀOE± ƒf •[ ƒ^‚â OE¤‹ † ŽÀ •Ñ‚ª ‹É ‚ß ‚Ä•-‚È‚¢•B ‰ß "n‰ž "š ‚ðˆµ‚ðˆµ ‚¤‰ð •Í-@‚AE‚µ‚Ä‚Í •AŽžŠÔ-̈aeOEvŽZ-@ ‚ª •s ‰Â OE ‡ ‚Å‚ ‚邪 •A‚±‚ê ‚Ü‚Å‚Ì OE¤‹ † ‚Í ‹K'¥ "g ' †‰ž "š ‚ðˆµ ‚¤Žü"g•"-Ì ˆae OEv ŽZ-@‚É•W' † ‚µ‚· ‚¬ ‚Ä‚« ‚½‚ae ‚¤‚Å‚ ‚é•B ŽžŠÔ-Ì ˆae‚Ì OE¤‹ † ‚Í •" •-‚È‚¢ ‚ª •A‚» ‚Ì '½‚-‚Í •q ‹ó ‹@ ‚Ì-£ "-'… ‚ð 'Î •Û‚AE‚µ‚½‚à‚Ì ‚Å‚ ‚Á‚½•B "n•Ó ‚ç3)•AKim ‚ç4)•A ƒ•ƒKƒt ƒ••[ ƒg ‹Z•p OE¤‹ †'g • ‡5)‚¨‚ae‚Ñ‚¨‚ae‚Ñ•¡ ˆä ‚ç6)‚Í •A •q ‹ó ‹@‚Ì-£ "-'… ‚ɂ‚¢ ‚ÄŽžŠÔ-Ì ˆae‰ð •Í ‚ðŽŽ‚Ý‚Ä‚¢ ‚é ‚ª •A-¬ 'Ì-Í ‚Ì Žae‚舵 ‚¢ ‚É•È-ª ‚ª ‚ ‚Á‚½‚è •Aƒ‚ ƒf ƒ‹ ‰» ‚Ì • §-ñ ‚ª ‚ ‚è•A"K-p "Í ˆÍ ‚ª OEÀ 'è ‚³ ‚ê ‚Ä‚¢ ‚é ‚ae‚¤‚Å‚ ‚é•B•Å‹ß •A '啼11))‚Í •AŽü"g •" ‰ž "š ŠÖ•" ‚AE ƒCƒ"ƒpƒ‹ ƒX ‰ž "š ŠÖ•" ‚ð 'g ‚Ý• ‡ ‚í ‚¹ ‚ÄŽž••-𠉞 "š ‚ð ‹• ‚ß ‚é •û-@‚ð ŠJ "-‚µ•AVLFS ‚Ì •s ‹K'¥ "g‚¨‚ae‚Ñg‚¨‚ae‚Ñ"®‰× •d ‚É'Î ‚· ‚é 'e •« ‰ž "š ‰ð •Í ‚É"K-p ‚µ‚Ä•A-Ç •D‚È•¸ "x ‚ðŠm "F ‚µ‚Ä‚¢ ‚é•B '啼‚Ì •û-@ ‚Í •A-l•X * ‰^-A •È'D"• ‹Z•p OE¤‹ †•Š OE´•eŽó-• •½•¬11"N7OEŽ9"ú •H‹G•u ‰‰ ‰ï‚É‚¨‚¢‰ï‚É‚¨‚¢ ‚Ä•u ‰‰ •½•¬11"N11OEŽ18,19"ú