摘要
水下工作的某產(chǎn)品特定結(jié)構(gòu)筒蓋系統(tǒng)，在工作后的常規(guī)檢查中，發(fā)現(xiàn)其聯(lián)接螺栓由于沖擊載荷的影響發(fā)生了斷裂，給整個系統(tǒng)造成了很大的安全隱患。本文以該問題為出發(fā)點，通過理論分析，構(gòu)造相關(guān)數(shù)學(xué)模型，并利用CAE軟件進(jìn)行模擬仿真，得出了較理想的結(jié)果，為解決這一類問題找到了一條途徑，對相關(guān)的設(shè)計、研發(fā)具有較大的理論意義和實際價值。
首先，本文以流固耦合理論為基礎(chǔ)，對筒蓋系統(tǒng)中的流體與各部件的相互作用建立了相關(guān)的數(shù)學(xué)模型，并得到流體和筒蓋結(jié)構(gòu)間的控制方程，從理論上分析了筒蓋系統(tǒng)在工作當(dāng)中破壞力的來源以及螺栓發(fā)生斷裂的關(guān)鍵原因。之后，借助于CAE軟件MSC.Patran進(jìn)行筒蓋系統(tǒng)的建模，利用MSC.Dytran進(jìn)行流固耦合分析，在軟件上還原筒蓋系統(tǒng)真實的工況環(huán)境，直觀的反映出在強大的沖擊載荷并伴隨流固耦合作用下，筒蓋系統(tǒng)瞬時發(fā)生了明顯的塑形變形。結(jié)果顯示，筒蓋系統(tǒng)在水下受外載荷激勵作用時，由于受附連水的影響，其系統(tǒng)固有頻率接近外載荷頻率，發(fā)生了受迫共振?；谶@一作用機理，本文提出了通過增加阻尼器進(jìn)行降載的優(yōu)化方案，并利用MSC.Dytran對該方案進(jìn)行模擬仿真。通過對比不同參數(shù)阻尼器的降載效果，得到了降載效果最佳的阻尼器參數(shù)范圍。結(jié)論表明，筒蓋系統(tǒng)的聯(lián)接螺栓可以用普通螺栓來替換原方案的高強度螺栓，并保證了整個系統(tǒng)的安全性。
在此過程中，本文還討論了筒蓋系統(tǒng)流固耦合模型的幾種校核方法以及求解其干、濕模態(tài)的研究方法，考慮了阻尼器化簡模型的建模和連接方式。結(jié)果表明，采用阻尼器進(jìn)行降載的方案能有效的將載荷降到普通螺栓的許用應(yīng)力范圍內(nèi)，完成了預(yù)定的研究目標(biāo)。








關(guān)鍵詞：流固耦合；有限元分析；MSC.Patran & MSC.Dytran & MSC.Nastran；阻尼器降載
Abstract
The specific structure called cover system of product underwater, in the conventional check after work, finding the connection bolt happened fracture because of impact load effect, and caused great security hidden danger. In this paper, we from the problem as a starting point, through the theoretical analysis, tectonic relation mathematical model, and through the powerful CAE software simulation, get the valuable parameters, found a new way to solve such problems, and it has great significance for related design, research.
This paper first established relevant mathematics models, which is suffer solid-fluid coupling effect of all part in cover system. And get control equations between the fluid and cover structure. Analysis the cover system the source of the destructive power in working and the key reasons of the fracturing bolts from theoretically. Later, with the aid of advanced CAE software MSC.Patran modeling, using MSC.Dytran for fluid-solid coupling analysis, simulate the cover system fluid-solid coupling model, and restore the real reduction working environment in cover system. Intuitive reflected that the cover system occurs obviously deformation when suffered strong impact load and the fluid-solid coupled function transiently. Through research on this process, to be sure, the cover system suffer load incentive effect underwater, because of the addition water effect, the natural frequency of the system is approach to the load frequency, and result in forced resonance. Base on this mechanism, put forward by increasing the damper to reduce load optimization scheme， and using MSC.Dytran for this scheme for simulation. Through comparing the different parameters of the damper down load effect, get the drop in the best effect of damper parameters range. Make connection bolts of cover system the can use ordinary bolts to replace the high strength bolts, and it could guarantee the safety of the whole system.
In the paper, discuss several checking methods of the cover system fluid-solid coupling model, and solve the dry and wet modal problem, considering the damper simplify modeling and connection type. It is conclude that the damper scheme can reduce load to the ordinary bolts of allowable stress range effectively, and makes the cover system normal work under complex loading.
Keywords: Fluid-solid coupling ; finite element analysis ; MSC. Patran & MSC. Dytran & MSC. Nastran ; Damper reduce load

目錄
摘要 I
Abstract II
第1章 緒論 1
1.1引言 1
1.2課題的研究背景 2
1.3國內(nèi)外研究現(xiàn)狀 3
1.3.1水下非接觸性碰撞的研究概況 3
1.3.2流固耦合力學(xué)的研究概況 4
1.3.3阻尼器降載的研究概況 7
1.4 課題研究的目的和意義 9
1.5 課題研究的內(nèi)容及創(chuàng)新點 9
第2章 課題的研究方法及相關(guān)理論 11
2.1 筒蓋系統(tǒng)的工作原理 11
2.2 筒蓋系統(tǒng)流體域的數(shù)學(xué)模型 12
2.3 筒蓋系統(tǒng)結(jié)構(gòu)域數(shù)學(xué)模型 14
2.3.1筒蓋系統(tǒng)力學(xué)模型 14
2.3.2筒蓋系統(tǒng)動力學(xué)模型 16
2.4 流固耦合系統(tǒng)相關(guān)理論 19
2.5相關(guān)的有限元計算方法 20
2.5.1 顯示非線性有限元計算方法 20
2.5.2 模態(tài)分析的有限元法 21
2.5.3 流體方程的有限元數(shù)值解法 23
2.5.4 流固耦合有限元處理方法 24
2.6 本章小結(jié) 25
第3章 筒蓋系統(tǒng)流固耦合有限元模型的建立 26
3.1 課題研究的相關(guān)軟件介紹 26
3.2 筒蓋系統(tǒng)流固耦合有限元模型 27
3.2.1 筒蓋系統(tǒng)有限元模型的建立 27
3.2.2 水域模型的有限元劃分 28
3.3 材料的選取 30
3.4 邊界條件的設(shè)置 31
3.4.1 筒蓋系統(tǒng)邊界條件的設(shè)置 31
3.4.2 水域的邊界條件設(shè)置 33
3.4.3 計算結(jié)果的輸出控制 34
3.4.4 相關(guān)參數(shù)的技術(shù)要求 34
3.5 本章小結(jié) 35
第4章 筒蓋系統(tǒng)有限元..