頁籤選單縮合
題 名 | 應力波時間差法應用於材質評估之研究(1)=Feasibility of Evaluating Lumber and Tree Quality by Using Stress Wave Method(Ⅰ) |
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作 者 | 莊世滋; 王松永; | 書刊名 | 林產工業 |
卷 期 | 16:4 1997.12[民86.12] |
頁 次 | 頁681-696 |
分類號 | 436.18 |
關鍵詞 | 柳杉; 原木; 應力波計時儀; 應力波波速; 動彈性係數; Japanese cedar; Log; Stress wave timer; Stress wave velocity; Dynamic modulus of elasticity; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究目的係探討應力波非破壞性檢測應用於柳杉原木、鼓型試材及實大樑之材 質可行性評估。其中 Hammer 打擊位置及應力波傳播路徑於應力波速度之影響,並探究不同 尺寸試材間之相關性。 所得結果如下:1. 應力波之再現性受原木直徑級之影響。2. 原木之 橫斷面、側邊及鼓型試材之端部與側邊,所測得經由 hammer 敲擊所產生之應力波波速,彼 此間可由下列關係式表示: 原木 Vend = 0.9904Vt - 119.82 鼓型試材 Vend = 1.4786Vt - 14453 Vend 係表示 hammer 敲擊端部所產生之應力波速 Vt 係表示由側邊所 測得之應力波速 3. 原木、鼓型試材及實大樑三者間之應力波速,具有下列之直線關係存在 :V1 = 0.968 Vb - 62.5 Vs = 0.9224Vb + 147.56 V1 = 1.0382Vs - 182.55 V1,Vs 及 Vb 分別代表原木、鼓型試材及實大樑之應力波速。4. 位於邊材領域之實大樑所 測得之應力波速度會明顯大於心材領域者;但兩者之動彈性係數則無明顯差異。 |
英文摘要 | This study was designed to investigate the effects of impacting position and direction of hammer on the stress wave velocity in logs,cantshaped boards and large rectangular beams of Japanese cedar ( Cryptomeria japonica D. Don), and the correlations among above three differece configuration of specimens. The results are summarized as follows:1.The reproducibility of stress wave is affected by log diameter. 2. The velocity of stress wave that were induced by hammer impacting on surface and ends of logs, and on edges and ends of cant-shaped boards could be represented by following linear regression formulas:log; Vend=0.9904 Vt-119.82 cant-shaped boards; Vend=1.4786 Vt-14453 Vend represent the velocity of stress wave which was induced by impacting hammer on the end, and Vt represent that measured from side impaction. 3.Correlations among stress wave velocities in logs, cant-shaped boards and large rectangular beams could be represented by a highly linear regression formulas as follows: V1 = 0.968 Vb - 62.5 Vs = 0.9224 Vb + 147.56 V1 = 1.0382 Vs - 182.55 V1, Vs and Vb represent respectively the stress wave velocity of logs, cantshaped boards and large rectangular beams. 4.The stress wave velocity in sapwood zone of large rectangular beams was significantly greater than those of hearwood section. However, significant differences not showed in their dynamic modulus of elasticity. |
本系統中英文摘要資訊取自各篇刊載內容。