發(fā)布時間：2018-04-24 19:01

  本文選題：滾動式張拉索節(jié)點 + 弦支穹頂　； 參考：《天津大學》2015年博士論文

【摘要】：弦支穹頂結(jié)構(gòu)施工的關鍵環(huán)節(jié)在于將預應力設計值準確地施加到結(jié)構(gòu)中去,工程中常采用張拉環(huán)索方式施加預應力。為減小索撐節(jié)點處的摩擦損失,可在撐桿下節(jié)點處運用滾動式張拉索節(jié)點。通過試驗方法研究這種引入了滾動式張拉索節(jié)點的弦支穹頂結(jié)構(gòu)的力學性能,并定量對比分析弦支穹頂與上部單層網(wǎng)殼的靜力性能,對評估滾動式張拉索節(jié)點弦支穹頂?shù)母咝苄跃哂兄匾饬x。由于橢球形弦支穹頂自身的幾何特征,張拉環(huán)索這一高效施工方式能否直接應用于橢球形弦支穹頂,直接影響了弦支穹頂?shù)耐茝V應用。滾動式張拉索節(jié)點的引入雖能有效減小摩擦損失,但既有研究表明其不能完全克服摩擦,因此在結(jié)構(gòu)的有限元分析中如何在單元層面考慮拉索與撐桿下節(jié)點間的摩擦,以準確評估結(jié)構(gòu)的整體性能。以及張拉過程中的預應力隨機誤差對結(jié)構(gòu)整體性能的影響,都是弦支穹頂結(jié)構(gòu)體系的理論研究過程中需要解決的問題。本文即針對這種采用了新型滾動式張拉索節(jié)點的弦支穹頂結(jié)構(gòu)展開了深入的研究。滾動式張拉索節(jié)點對結(jié)構(gòu)性能改善程度的最直接衡量標準是檢測出節(jié)點兩側(cè)索力值,以計算該節(jié)點處的預應力摩擦損失值�；谥苯訙y量法提出了一種適用于弦支穹頂結(jié)構(gòu)試驗研究的索力測試方法,并通過試驗研究、理論分析驗證其可靠性及應用范圍。提出了一種適用于張弦結(jié)構(gòu)體系的等效摩擦單元,進而建立了張弦結(jié)構(gòu)考慮拉索與撐桿下節(jié)點間摩擦的有限元分析方法,并通過試驗研究驗證了該摩擦單元的適用性。將等效摩擦單元應用到張弦桁架結(jié)構(gòu)的有限元分析中,得到了預應力摩擦損失對張弦桁架結(jié)構(gòu)整體性能的影響規(guī)律。分別開展了帶滾動式張拉索節(jié)點的弦支穹頂結(jié)構(gòu)和其上部單層網(wǎng)殼結(jié)構(gòu)的理論分析和試驗研究,并對比分析了弦支穹頂和相應單層網(wǎng)殼的靜力性能�；趩螌泳W(wǎng)殼內(nèi)的力流傳遞規(guī)律和桿件的空間位置關系,提出了一種桿件內(nèi)力近似計算方法,推導了網(wǎng)殼在球坐標系下的有限元計算方法;建立茌平體育館弦支穹頂?shù)?:10縮尺模型,拉索張拉前開展了單層網(wǎng)殼的靜力試驗,得到了單層網(wǎng)殼在半跨和全跨荷載作用下的內(nèi)力分布特征,同時驗證了理論分析的正確性;開展了弦支穹頂?shù)膹埨囼灪挽o力試驗,采用高精度的激光跟蹤儀全程跟蹤測量關鍵測點位移,揭示了弦支穹頂張拉過程中的結(jié)構(gòu)內(nèi)力和變形變化規(guī)律,得到了弦支穹頂在全跨與半跨荷載作用下的內(nèi)力分布特征。針對橢球形弦支穹頂結(jié)構(gòu)同圈環(huán)索內(nèi)力有可能不等,從而不能采用張拉環(huán)索這一高效施工方式的情況,分析了3種常見橢球形弦支穹頂結(jié)構(gòu)索撐體系的初始平衡態(tài),得到了橢球形索撐體系同圈環(huán)索內(nèi)力相等的必要條件;針對同圈環(huán)索內(nèi)力不等的案例,采用擴展力密度法對索撐體系重新找形,得到了同圈環(huán)索內(nèi)力相等時的形態(tài);根據(jù)環(huán)索內(nèi)力的分布規(guī)律提出了張拉環(huán)索時張拉點的合理布置建議。弦支穹頂結(jié)構(gòu)的預應力誤差不可必免地存在,基于概率統(tǒng)計原理,以一實際工程為背景,研究了弦支穹頂結(jié)構(gòu)的各項力學性能對環(huán)索內(nèi)力隨機誤差的敏感性,以及隨機誤差對各項力學性能的具體影響程度。明確了弦支穹頂結(jié)構(gòu)最外圈環(huán)索在結(jié)構(gòu)中的重要作用以及對結(jié)構(gòu)的重要影響程度,提出了弦支穹頂預應力施工過程中嚴格控制最外圈環(huán)索內(nèi)力張拉精度的建議。
[Abstract]:The key to the construction of the stringed dome is to apply the prestress design value to the structure accurately. In the project, the tensioning cable is often used to apply the prestress. In order to reduce the friction loss at the bracing joints, the rolling tension cable joints can be applied to the joints under the braces. The rolling tension is introduced through the test method. The mechanical properties of the chord dome structure of the cable node and the quantitative comparison and analysis of the static performance of the chord dome and the upper single layer reticulated shell are of great significance to the evaluation of the high efficiency of the chord dome of the rolling tension cable. The ellipsoidal dome directly affects the extension and application of the chord dome. The introduction of the rolling tension cable node can effectively reduce the friction loss, but the research shows that it can not completely overcome the friction. Therefore, in the finite element analysis of the structure, how to consider the friction between the cables and the braces at the element level in the finite element analysis is to accurately evaluate the knot. The overall performance of the structure and the influence of the prestress random error on the overall performance of the structure are all problems to be solved in the theoretical study of the chord dome structure system. This paper is aimed at the deep research on the string dome structure which adopts the new type of rolling tension cable joints. The most direct measure of the improvement of the structural performance is to detect the cable force values on both sides of the node to calculate the loss of the prestressed friction loss at the node. Based on the direct measurement method, a cable force test method suitable for the test study of the chord dome structure is proposed. The reliability and application model of the test is verified by theoretical analysis. An equivalent friction unit suitable for the tension string structure system is proposed, and a finite element analysis method is established for the tension string structure to consider the friction between the cables and the braces. The applicability of the friction element is verified by the experimental study. The equivalent friction unit is applied to the finite element analysis of the tension string truss structure. The influence of the stress friction loss on the overall performance of the tension string truss structure. The theoretical analysis and experimental study of the chord dome structure with the rolling tension cable joints and the upper single layer reticulated shell are carried out respectively, and the static performance of the chord dome and the corresponding single layer reticulated shell is compared and analyzed. The approximate calculation method of the internal force of the rod is presented, and the finite element calculation method of the reticulated shell in the spherical coordinate system is derived. The 1:10 scale model of the chord dome in Chiping gymnasium is established. The static test of the single layer reticulated shell is carried out before the cable tension is drawn, and the single layer reticulated shell is subjected to half span and full span load. The characteristics of the internal force distribution and the correctness of the theoretical analysis are verified. The tension test and static test of the chord dome are carried out. The displacement of the key points is measured by a high-precision laser tracker, and the structural internal force and the deformation and transformation law of the chord dome are revealed, and the full span and half span load of the chord dome are obtained. The initial equilibrium state of the bracing system of 3 common ellipsoidal stringed dome structures is analyzed. The ellipsoidal bracing system is equal to the inner force of the ring cable. According to the case of unequal inner force in the same ring, the extended force density method is used to find the shape of the cable bracing system again, and the shape of the cable internal force is equal. According to the distribution law of the ring cable internal force, the reasonable arrangement of the tension point of the tension ring is put forward. The prestress error of the string dome structure can not exist without necessity. Based on the principle of probability and statistics and taking a practical project as the background, the sensitivity of the mechanical properties of the chord dome to the random error of the ring cable internal force and the specific influence of the random error on the mechanical properties are studied. The important role of the outer ring cable in the stringed dome structure and the important shadow on the structure are clarified. It is suggested that the tensioning accuracy of the outer ring cable should be strictly controlled during the prestressing construction of the suspended dome.

【學位授予單位】：天津大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TU399
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本文編號：1797835