船舶氣囊下水的力學(xué)計(jì)算及工藝優(yōu)化

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縱觀世界工業(yè)的發(fā)展趨勢，從批量流水定型生產(chǎn)方式向適應(yīng)多元變型的柔 性生產(chǎn)方式轉(zhuǎn)變已成定局；再看我國船舶行業(yè)的發(fā)展，沿海和內(nèi)河中小型船廠 造船模式的改造已迫在眉睫。 一種極為靈活的修造船企業(yè)模式正在悄悄地取代 傳統(tǒng)的修造船企業(yè)模式而引起造船生產(chǎn)組織的一場變革，而氣囊下水正是在這

場變革中應(yīng)運(yùn)而生的高適應(yīng)能力的“柔性下水技術(shù)”。

目前，船用氣囊下水工藝技術(shù)已非常成熟，兩項(xiàng)船用氣囊標(biāo)準(zhǔn)：《船舶上排、

下水用氣囊》CB3795-1996 和《船舶用氣囊上排、下水工藝要求》CB3837-1998

的頒布，更是為船用氣囊下水工藝提供了理論依據(jù)。但隨著采用氣囊下水船舶  尺度的增大，下水過程中的不確定因素增加，船用氣囊下水的風(fēng)險(xiǎn)也隨之增大， 因此要解決下水安全問題這一發(fā)展瓶頸，就必須不斷提高氣囊的承載能力和制  定更加合理的下水方案。為此，本文圍繞氣囊的力學(xué)計(jì)算和下水工藝方案的制  定展開討論，并對(duì)現(xiàn)有氣囊技術(shù)水平下的下水船重界限做出預(yù)估，以期達(dá)到提

高氣囊的下水能力，增加這種柔性下水方式的經(jīng)濟(jì)性和安全性的目的。

本文首先以自由狀態(tài)下氣囊受壓前后主應(yīng)力變化為依據(jù)，討論內(nèi)壓的變化 規(guī)律，研究單個(gè)氣囊的技術(shù)參數(shù)和各參數(shù)間的相互關(guān)系，并采用有限元方法對(duì)

氣囊的強(qiáng)度理論研究進(jìn)行了初探，為后續(xù)下水計(jì)算做準(zhǔn)備。

其次，討論氣囊下水工藝兩個(gè)階段的實(shí)際操作和技術(shù)要求，研究氣囊下水 第二階段船體的運(yùn)動(dòng)和受力情況，并分別采用傳統(tǒng)靜力學(xué)方法和改進(jìn)后的彈性

計(jì)算方法，解決尾浮時(shí)艏部氣囊的超負(fù)荷承壓的計(jì)算。

再次，是本文的重點(diǎn)：在前兩章研究的基礎(chǔ)上，以15800t  散貨船實(shí)船為

例，設(shè)計(jì)不同的下水工藝方案，并從安全性、經(jīng)濟(jì)性、合理性三個(gè)方面對(duì)不同

方案進(jìn)行比較，進(jìn)行方案選優(yōu)。

最后，總結(jié)本文研究的主要結(jié)論，提出研究中存在的不足之處，并指出進(jìn)

一步研究的發(fā)展方向。

關(guān)鍵字：柔性下水技術(shù)，船用氣囊下水工藝，承載能力，有限元分析，彈性計(jì)

算方法，優(yōu)化方案

Abstract

Lets  look  at  the  developing  trend  of  the  world  industry,the  diversified  soft mode of production must be instead of the batch flowline production.The small and  medium shipyards must transforn the shipbuilding mode along the coast and river in  the internal  ship industry of our country.The conventional  shipbuilding mode has  being  changed  by   an  new  flexible  mode  which  will  arousing  a  transform  of shipbuilding production organization.Ship launching with airbag which is a flexible  technology  of  high  adaptability  emerges  as  the  times  require  along  with  the

transform.

Although the technology of ship launching with airbag is perfect at present,it has higher risk of dangerous along with the augment of launching ship's weight and  the increasing of the indeterminate factors.We must advance the loading carrying  capacity of airbag and make more reasonable launching project to settle the safety  problems which restrict the development of this flexible technology.So this paper  discusses the airbag's mechanic calculation and how to make the launching project.  For the intent of improving the launching carrying capability and the economical  efficiency it also estimates the highest launching weight under the technical level in

existence.

First according as the main stress changing when the airbag is impressed under the freedom station,this paper discusses the changing rule of the inner pressure and research  airbag's  limited   strength  by  the   finite  element  analysis  method.It  also analyzes the technology  factors  and  correlations  of the  technology  factors  of the

single airbag to prepare for the later calculations.

Secondly  this  paper  discusses   fact  operations  and  technology  requirements during the two steps of the launching courses.It also analyzes the movements and forces of the hull during the second step and calculates the exceeding loading of the airbag under the stem when the stern is floating by two manners of the traditional

static calculation and improving elastic calculation.

Thirdly  this  paper  designs  different  process  programs  for  the   15800T  Bulk Carrier  and  optimizes  the  project  considering  the  safety  and  the  economical

efficiency in the base of two before chapters.It is also the emphasis of the paper.

Finally summarize the conclusions and the defects of the research and indicates

the development direction of the further research.

Key words: flexible launching technology,ship launching with airbag technology, loading   carrying   capacity,finite   element   analysis,elastic   calculation   method,

optimize project