形狀記憶合金力學特性之研究

A Study on the Mechanical Property of Shape Memory Alloy

胡友文(You-Wen Hu)

指導教授 ： 葉隆吉

大同大學/工程學院/機械工程學系所/碩士(2006年)

摘要

形狀記憶合金的記憶效應是藉由溫度的升降所引起的相變化來驅動，由先前的研究發現，SMA在不同電流的加熱下，呈現出不同的剛性，會有不同的負荷能力。所以本研究假設SMA的剛性為其自身溫度的函數，以懸臂樑的方式研究SMA的力學特性，通以不同的電流，在不同的操作溫度下，量測其荷重與變形量，再將結果代入計算樑撓度的公式，估算其等效的彈性係數(E)。如此藉由一系列的實驗資料及分析結果，迴歸分析出彈性係數隨溫度而變化的函數關係。 實驗結果顯示，SMA在100%沃斯田體與100%麻田散體相變化範圍內，其彈性係數會受到自身溫度的影響，在這兩個相變化範圍內，SMA於形狀記憶效應範圍內，在其彈性限以下，其彈性係數與溫度呈非線性關係，本研究藉由實驗數據，建立了彈性係數與溫度的理論關係式。

關鍵字

形狀記憶合金 ； 彈性係數

並列摘要

The shape memory effect of the shape memory alloy (SMA) was driven by its phase transformation caused by temperature change. Previous researches show that the SMA present different stiffness and loading ability under different operating temperature. This study makes assumption as the stiffness of SMA is a function of its temperature. A cantilever beam with SMA was heated by electric current. Then, the load and deflection under different operation temperature of SMA cantilever beam were measured. The results were used to estimate the elastic modulus (E) of the SMA by the cantilever beam deflection formula. A series of experiments were carried out in the study. The experimental results were used to define the relative function between elastic modulus of SMA with temperature by the regression analysis method.
Experimental results shown that the elastic modulus of SMA depends on its temperature in the shape transformation range form 100% austenite to 100% martensite. In this phase transformation range and under its elastic limit of shape memory effect range , the relationship of elastic modulus of SMA with temperature is nonlinear. A theoretical expression of elastic modulus of SMA with its temperature was established here.

並列關鍵字

Shape Memory Alloy ； Elastic Modulus

參考文獻

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