【摘要】：頂張力立管作為海洋油氣開發(fā)的重要設(shè)備，其穩(wěn)定性尤為重要。參數(shù)激勵(lì)的不穩(wěn)定性是實(shí)際立管面臨的一大挑戰(zhàn)，一旦被激發(fā)將使立管極度不穩(wěn)定，影響海洋油氣開發(fā)的正常開展，嚴(yán)重時(shí)將帶來重大經(jīng)濟(jì)損失和環(huán)境污染。 有效預(yù)測(cè)此立管穩(wěn)定性，并指導(dǎo)工程設(shè)計(jì)是避免災(zāi)難發(fā)生的關(guān)鍵。當(dāng)前研究預(yù)測(cè)參量激勵(lì)的不穩(wěn)定性大都基于規(guī)則波進(jìn)行探討，即假定實(shí)際參數(shù)激勵(lì)為單頻諧波激勵(lì)。然而，實(shí)際海洋環(huán)境具有很大隨機(jī)性，波浪對(duì)于海洋平臺(tái)的激勵(lì)是多頻疊加的隨機(jī)載荷，導(dǎo)致立管中張力隨機(jī)性波動(dòng)，，因此以單頻激勵(lì)預(yù)測(cè)張力波動(dòng)形態(tài)不符合實(shí)際，其預(yù)測(cè)結(jié)果的準(zhǔn)確性會(huì)受到很大影響。 與此同時(shí)，由于海洋環(huán)境即波浪和洋流作用力的隨機(jī)性，以及立管本身的結(jié)構(gòu)尺寸和材料特性存在的隨機(jī)性，立管的參量穩(wěn)定性設(shè)計(jì)存在很大的不確定性，而傳統(tǒng)方法大都基于確定性參數(shù)進(jìn)行研究，因此其預(yù)測(cè)得到的穩(wěn)定性受到現(xiàn)實(shí)隨機(jī)性的嚴(yán)峻挑戰(zhàn)。 此外，工作于隨機(jī)海洋環(huán)境下的頂張力既受到海洋表面波浪力作用又受到洋流繞流立管產(chǎn)生周期性渦激勵(lì)力作用，僅考慮前者作用將導(dǎo)致參量共振，僅考慮后者作用將導(dǎo)致渦激振動(dòng)。而實(shí)際海洋環(huán)境下，立管可能同時(shí)受到兩種周期性作用而使立管不穩(wěn)定，因此有必要考慮周期性波浪和渦同時(shí)作用下立管的動(dòng)力穩(wěn)定性。 為解決以上問題，本文從以下三個(gè)方面展開，對(duì)頂張力立管在隨機(jī)海洋環(huán)境下的穩(wěn)定性進(jìn)行深入研究: 1.基于線性波浪理論和P-M海浪譜，預(yù)測(cè)實(shí)際海洋環(huán)境中的波浪載荷得到多頻參數(shù)激勵(lì)，推導(dǎo)多頻激勵(lì)下立管的參量穩(wěn)定性Hill方程，運(yùn)用Bubnov Galerkin法求解相應(yīng)方程得到Hill穩(wěn)定性圖。探討多頻激勵(lì)預(yù)測(cè)立管系統(tǒng)參量穩(wěn)定性特點(diǎn)，對(duì)比多頻激勵(lì)產(chǎn)生的Hill穩(wěn)定性圖和傳統(tǒng)采用單頻激勵(lì)產(chǎn)生Mathieu穩(wěn)定性圖，分析傳統(tǒng)方法研究存在的不足。基于Hill穩(wěn)定性圖預(yù)測(cè)實(shí)際海洋環(huán)境下立管的參量穩(wěn)定性，并提出抑制或消除不穩(wěn)定性的方法。 2.考慮海洋環(huán)境、結(jié)構(gòu)設(shè)計(jì)和材料特性存在的不確定性，對(duì)影響立管參量穩(wěn)定性的隨機(jī)性因素進(jìn)行敏感性分析，確定對(duì)參量穩(wěn)定性影響較大的關(guān)鍵因素。建立代理模型模擬不確定因子和輸出響應(yīng)之間的關(guān)系,以及進(jìn)行隨后的可靠性分析。計(jì)算在關(guān)鍵因素影響下立管參量穩(wěn)定的可靠度，并分析每個(gè)因素對(duì)可靠度影響的規(guī)律。結(jié)合可靠性分析，提出抑制和消除不穩(wěn)定性的方法。 3.考慮參數(shù)和渦同時(shí)作用于頂張力立管，推導(dǎo)相應(yīng)的動(dòng)力學(xué)方程，并計(jì)算其動(dòng)力響應(yīng)，比較其與參量共振和渦激振動(dòng)之間的差異。在參數(shù)和渦共同激勵(lì)作用下，深入分析各相關(guān)變量對(duì)立管動(dòng)力穩(wěn)定性的影響。分別分析渦和參數(shù)激勵(lì)對(duì)共同激勵(lì)不穩(wěn)定性的影響規(guī)律。討論減弱或避開不穩(wěn)定性的措施。
[Abstract]:As an important equipment for offshore oil and gas development, the stability of top tension riser is particularly important. The instability of parametric excitation is a great challenge to the actual riser. Once excited, the riser will be extremely unstable, which will affect the normal development of offshore oil and gas development, and will bring serious economic losses and environmental pollution. Effectively predicting the stability of the riser and guiding the engineering design is the key to avoid the disaster. At present, the instability of prediction parameter excitation is mostly discussed based on regular wave, that is to say, the actual parameter excitation is assumed to be single frequency harmonic excitation. However, the actual marine environment has a lot of randomness, and the wave excitation to the offshore platform is a random load of multi-frequency superposition, which leads to the random fluctuation of tension in riser, so the prediction of tension fluctuation pattern by single frequency excitation is not in line with the reality. The accuracy of the prediction results will be greatly affected. At the same time, due to the randomness of ocean environment, namely wave and ocean current forces, and the randomness of structural size and material characteristics of riser itself, the parametric stability design of riser is very uncertain. However, the traditional methods are mostly based on deterministic parameters, so the stability of the prediction is severely challenged by the randomness of reality. In addition, the top tension working in random marine environment is not only subjected to the wave force on the ocean surface but also to the periodic vortex excitation force produced by the ocean current around the current riser. Only considering the former action will lead to parametric resonance. Only considering the latter effect will lead to vortex-induced vibration. In the actual marine environment, the riser may be unstable by two periodic actions at the same time, so it is necessary to consider the dynamic stability of riser under the simultaneous action of periodic waves and vortices. In order to solve the above problems, the stability of top tension riser in random marine environment is studied in the following three aspects: 1. Based on the linear wave theory and P-M wave spectrum, the multi-frequency parametric excitation is obtained by predicting the wave loads in the actual marine environment. The Hill equation of parametric stability of risers under multi-frequency excitation is derived, and the Hill stability diagram is obtained by using the Bubnov Galerkin method. The characteristics of parametric stability prediction of riser system by multi-frequency excitation are discussed. Compared with Hill stability diagram generated by multi-frequency excitation and Mathieu stability diagram generated by traditional single-frequency excitation, the shortcomings of traditional method are analyzed. Based on Hill stability diagram, the parametric stability of riser in real marine environment is predicted, and a method to suppress or eliminate instability is proposed. 2. Considering the uncertainty of marine environment, structural design and material characteristics, the random factors affecting the parametric stability of risers are analyzed, and the key factors affecting the parametric stability are determined. An agent model was established to simulate the relationship between the uncertainty factor and the output response, and the subsequent reliability analysis was carried out. The reliability of riser parametric stability is calculated under the influence of key factors, and the regularity of each factor on reliability is analyzed. Combined with reliability analysis, the method of restraining and eliminating instability is put forward. Considering that the parameters and vortices act on the top tension riser at the same time, the corresponding dynamic equations are derived, and the dynamic responses are calculated, and the differences between them and parametric resonance and vortex-induced vibration are compared. Under the joint excitation of parameters and vortices, the influence of each related variable on the dynamic stability of the tube is analyzed in depth. The effects of vortex and parametric excitation on the instability of common excitation are analyzed respectively. Discuss measures to reduce or avoid instability.
【學(xué)位授予單位】：上海交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：P742;P756.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 楊和振;李華軍;;Instability Assessment of Deep-Sea Risers Under Parametric Excitation[J];China Ocean Engineering;2009年04期

2 唐友剛;邵衛(wèi)東;張杰;王麗元;桂龍;;深海頂張力立管參激-渦激耦合振動(dòng)響應(yīng)分析[J];工程力學(xué);2013年05期

3 李效民;郭海燕;孟凡順;;內(nèi)流對(duì)頂張力立管動(dòng)力響應(yīng)影響分析(英文)[J];船舶力學(xué);2010年09期

4 盧其進(jìn);楊和振;;母船垂蕩導(dǎo)致ROV臍帶纜參量共振的研究[J];海洋技術(shù);2011年03期

5 唐友剛;張素俠;張海燕;張若瑜;;系泊系統(tǒng)松弛-張緊引起的沖擊張力研究[J];振動(dòng)與沖擊;2008年04期

6 徐萬海;吳應(yīng)湘;鐘興福;何楊;劉培林;馮現(xiàn)洪;;海洋細(xì)長(zhǎng)結(jié)構(gòu)參數(shù)激勵(lì)不穩(wěn)定區(qū)的確定方法[J];振動(dòng)與沖擊;2011年09期

7 李清泉;楊和振;;深海臍帶纜內(nèi)套管間相互作用的研究[J];中國(guó)海洋平臺(tái);2010年06期

8 唐友剛,林維學(xué),董艷秋,田凱強(qiáng);船舶參數(shù)激勵(lì)和強(qiáng)迫激勵(lì)作用下的非線性運(yùn)動(dòng)響應(yīng)[J];中國(guó)造船;2001年02期

9 唐友剛;鄺艷香;李紅霞;;初穩(wěn)性高時(shí)變特性對(duì)橫搖運(yùn)動(dòng)的影響[J];中國(guó)造船;2008年02期

相關(guān)碩士學(xué)位論文 前1條

1 王愛軍;深海臍帶纜動(dòng)力響應(yīng)及彎曲加強(qiáng)器可靠性研究[D];上海交通大學(xué);2012年

本文編號(hào)：2124057