頁籤選單縮合
題 名 | 新興梨之物性的感測與分析=The Detection and Analysis of Physical Properties for Hsin-Hsing Pear |
---|---|
作 者 | 黃得時; 白世煜; 黃裕益; 鄭經偉; | 書刊名 | 農業機械學刊 |
卷 期 | 8:3 1999.09[民88.09] |
頁 次 | 頁21-33 |
分類號 | 432.312 |
關鍵詞 | 梨; 破壞及非破壞性檢測; 彈性模數; Pear; Nondestructive and destructive experiment; Young's modulus; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究旨在利用衝擊脈波的激振方式找出時藏期間新興梨的頻率響應特性與 質量、堅實度、彈性模數等物性對時間及彼此間的關係。 本試驗方法乃是將梨子時藏於溫度 4 ℃ ' 相對溼度 85% 的恆溫恆濕箱中 , 每隔 三天 , 以衝擊槌激振之 , 並利用加速度計量測其頻率響應 , 最後再利用公式計算 出試驗梨之彈性模數。此外 , 為驗證非破壞性質驗結果 , 本研究再將六顆實驗組 的梨子切闕 , 並利用 IIISKOEl 萬能試驗機做堅實度試驗。並以有限元索法模擬彈 , 世 球 , 以試驗所量測的彈性模數、密度、浦松比 (0.49) 為材料性質 , 求彈性球的 共振頻率再與所量測之共振頻率加以分析比較。 試驗結果顯示 , 質量與頻率皆隨時間呈線性遞減 , 質量較小者其共振頻率相 對較高且其隨時間之衰減速度也較快。新興梨之彈性模數會隨時間里指數衰滅 , 且質量愈小者衰減速度愈快 , 彈性模數與堅實度變化趨勢一致 , 但是前者之衰減 速度較慢。使用有限元素法分析所得之共振頻率與衝擊脈波的激振方式產生的共 振頻率相當接近 , 驗證彈性球理論適用於球狀果賞。 |
英文摘要 | This study focuses on the using the impulsive excitation method to find out the relationship between the time and the pears' physical characteristics in the storing period such as frequency response characteristics, mass, firmness, modulus elasticity, of etc., and those physics' mutual relationship. The pears were stored inside a box of 40 o C constant temperature and 85% humidity relative. In every three days, we use the impulsive hammer to vibrate all the fruits and the accelerometer to measure the signals of frequency response. Finally, the Pears' Young's Modulus can be calculated by using formula derived. To verify the nondestructive experimental results, this study takes six pears from the experimental group to do the destructive experiment including the firmness. Furthermore, by use of the Finite Element Method, the elasticity ball could be simulated, and then the Young's modulus, density, and Poisson's ration measured from the tests were applied to be the material properties in order to get the resonant frequency of the elasticity ball, and then compare it with the test one. .The results showed that the mass and frequency were linearly-decreasing progressively, and when the mass was smaller, the resonant frequency was relatively higher, and its. decaying speed was faster. The elasticity modulus was decaying exponentially with respect to the time. Moreover, when the mass was smaller,. the decaying speed was faster, and the changing tendencies of the Young's modulus and firmness were coincident, but their decaying speeds were slower. After being analyzed by Finite Element, the resonant frequency was close to that measured by the impulsive excitation, and the results verified that the theory of elasticity ball was applicable to the globoid fruits. |
本系統中英文摘要資訊取自各篇刊載內容。