本文選題：形狀記憶合金棒　切入點(diǎn)：受限回復(fù)　出處：《華南理工大學(xué)》2013年碩士論文

【摘要】：由于形狀記憶合金的優(yōu)良特性，其在土木工程領(lǐng)域的應(yīng)用具有廣闊前景。若將形狀記憶合金棒制成螺栓用于地鐵盾構(gòu)管片，則當(dāng)管片因外力出現(xiàn)某種程度張開時(shí)，利用形狀記憶合金的受限回復(fù)性能可為管片提供一定的閉合回復(fù)力，進(jìn)而為后續(xù)被動修復(fù)創(chuàng)造更有利的條件。為此，本文對NiTi形狀記憶合金棒的受限回復(fù)性能和加熱方法進(jìn)行了初步研究，主要工作包括以下三部分： （1）通過形狀記憶合金棒的拉伸與剪切受限回復(fù)試驗(yàn)，，考察了殘余變形不同時(shí)受限回復(fù)力隨溫度的變化關(guān)系。研究表明：隨著形狀記憶合金棒的殘余變形增大，無論是升溫階段還是降溫階段的最大受限回復(fù)力均隨之增加；形狀記憶合金棒以及約束裝置的熱脹冷縮將對試件的受限回復(fù)力產(chǎn)生較大影響。 （2）基于Brinson模型對形狀記憶合金棒的拉伸受限回復(fù)過程進(jìn)行了理論分析，指出了其存在的主要問題，并對此進(jìn)行了改進(jìn)；隨后，基于改進(jìn)的Brinson模型再次進(jìn)行了理論分析，發(fā)現(xiàn)不同拉伸殘余應(yīng)變情況下形狀記憶合金棒升溫階段的計(jì)算曲線以及降溫階段的前半部分計(jì)算曲線均與試驗(yàn)曲線吻合較好，特別是計(jì)算所得最大受限回復(fù)力與試驗(yàn)實(shí)測值較為接近。 （3）提出了一種新的形狀記憶合金棒材加熱方法，進(jìn)行了相應(yīng)的加熱試驗(yàn)和計(jì)算分析，初步驗(yàn)證了其可行性。研究表明：采用提出的加熱方法，SMA棒從常溫升至110℃所需時(shí)間小于20min，升溫效率較高，效果良好。
[Abstract]:Because of the excellent properties of shape memory alloy, its application in the field of civil engineering has a broad prospect. If the shape memory alloy bar is made into bolt to be used in metro shield segment, when the segment is opened to some extent due to external force, The limited recovery properties of shape memory alloys can provide a certain closed recovery force for the segments, and thus create more favorable conditions for passive restoration. In this paper, the limited recovery properties and heating methods of NiTi shape memory alloy rods are studied. The main work includes the following three parts:. 1) through tensile and shear confined recovery tests of shape memory alloy bars, the relationship between temperature and residual deformation is investigated. The results show that the residual deformation of shape memory alloy rods increases with the increase of residual deformation. The maximum limited recovery force increases in both the heating stage and the cooling stage, and the thermal expansion and contraction of the shape memory alloy bar and the restraint device will have a great impact on the limited recovery force of the specimen. (2) based on Brinson model, the tensile limited recovery process of shape memory alloy rod is theoretically analyzed, and the main problems are pointed out and improved. Then, based on the improved Brinson model, theoretical analysis is carried out again. It is found that the calculated curves of the heating stage and the first half of the cooling phase of the shape memory alloy bars under different tensile residual strains are in good agreement with the experimental curves. In particular, the calculated maximum limited recovery force is close to the measured value. A new heating method of shape memory alloy bar is proposed, and the corresponding heating test and calculation analysis are carried out. The feasibility of the method is preliminarily verified. The results show that the proposed heating method takes less than 20 minutes to rise from room temperature to 110 鈩

本文編號：1657879