| DC 欄位 |
值 |
語言 |
| DC.contributor | 機械工程學系 | zh_TW |
| DC.creator | 孫念魯 | zh_TW |
| DC.creator | Nian-Ru Hsin | en_US |
| dc.date.accessioned | 2000-6-28T07:39:07Z | |
| dc.date.available | 2000-6-28T07:39:07Z | |
| dc.date.issued | 2000 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:444/thesis/view_etd.asp?URN=87323003 | |
| dc.contributor.department | 機械工程學系 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 首先我們對單一熱交換管與端板接合問題進行分析，其次再分析多熱交換管依續擴管問題。在分析過程中，以非線性有限元素法的觀念為基礎，使用有限元素分析軟體ABAQUS，對準二維的軸對稱模型及實際的三維模型進行應力分析。
經過模型的建立到軟體的分析，我們可以發現最大殘留張應力會發生在熱交換管中接近端板底部附近的元素，此處即為最容易發生應力腐蝕的地方，因為應力腐蝕作用只會發生在殘留張應力存在之處。這點與實際上觀察熱交換管應力腐蝕破裂的情形是一致的。而由實際的三維模型分析結果發現，最先擴管完成的熱交換管，在管與管間以正三角形方式排列的模型中，其最大殘留張應力值受到鄰近管擴管的影響較大。另外，腐蝕環境也是造成應力腐蝕破裂的重要因素，在進行熱交換管與端板的擴管接合設計時，必須同時考慮到最大殘留張應力可能發生的區域及所用金屬容易發生應力腐蝕破裂的環境，以避免熱交換管因為應力腐蝕的產生而比預估的壽命提早破裂。 | zh_TW |
| dc.description.abstract | In the problem with the connection of heat exchanger tubes and a tube sheet, we first analyze residual stresses of the tube connecting to the tube sheet. Then, we analyze that of the tube after the others are dilated one by one. The residual stress in the joints of exchanger tubes and a tube sheet will be investigated using non-linear finite element method and the finite element package “ABAQUS” is applied in this study. The results will be used to predict where the stress corrosion phenomenon occurs.
From the results of analysis, we can find that the maximum residual stress appears at the parts of the tube which are near the bottom of the tube sheet. There is the place where the stress corrosion cracking (SCC) occurs , because SCC appears in the elements with residual tensile stresses only. This result is very consistent with the real observations. In the results of analyzing problems with the 3D models, it is more clear that the maximum value of residual tensile stresses in the tube which was dilated first is affected by dilating that around in the model which tubes are arranged as equilateral triangle. In addition, it is important that the corrosion environments are factors of SCC, and they should be considered when heat exchangers are designed. | en_US |
| DC.subject | 熱交換器 | zh_TW |
| DC.subject | 殘留應力 | zh_TW |
| DC.subject | 應力腐蝕 | zh_TW |
| DC.subject | 有限元素分析 | zh_TW |
| DC.subject | Heat Exchanger | en_US |
| DC.subject | Residual Stress | en_US |
| DC.subject | Stress Corrosion | en_US |
| DC.subject | Finite Element Analysis | en_US |
| DC.title | 熱交換器之熱換管及端板擴管殘留應力分析 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |