以圓柱實心桿件試體長軸與橫截面共振頻率量測材料動卜松比之檢測技術TESTING TECHNIQUE FOR DETERMINATION OF THE DYNAMIC POISSON'S RATIO OF A MATERIAL WITH LONGITUDINAL AND CROSS-SECTIONAL RESONANT FREQUENCIES OF A CIRCULAR SOLID ROD SPECIMEN

專利類型

發明

專利國別 (專利申請國家)

美國

專利申請案號

13/083,614

專利證號

US 8,485,033 B2

專利獲證名稱

以圓柱實心桿件試體長軸與橫截面共振頻率量測材料動卜松比之檢測技術TESTING TECHNIQUE FOR DETERMINATION OF THE DYNAMIC POISSON'S RATIO OF A MATERIAL WITH LONGITUDINAL AND CROSS-SECTIONAL RESONANT FREQUENCIES OF A CIRCULAR SOLID ROD SPECIMEN

專利所屬機關 (申請機關)

國立臺灣科技大學

獲證日期

2013/07/16

技術說明

美國ASTM 許多規範均有說明應用非破壞試驗法量測材料卜松比的檢測技術，共通的流程依序為事先測得材料動態彈性模數及動態剪力模數，再計算求得動態卜松比，惟規範中均提到計算動材料態剪力模數時所須量測的材料扭曲共振頻率，不易由實務試驗中獲得。 本技術係根據波動理論，分析圓形實心桿件在一維振動所得之軸向基本共振頻率，以及導波法之橫斷面基本共振頻率，經數值分析、整理與回歸後，以修正形狀因數(modified shape factor)為參數，得到計算材料動態卜松比所需的數學公式。量測圓形實心桿件之軸向及橫斷面基本共振頻率的技術有很多種，本專利申請以已在工程界廣為使用之敲擊回音法(impact-echo method)作為範例說明，進行試驗時，首先針對桿件之軸向敲擊以獲得軸向共振頻率，接著於桿件表面中央位置進行橫斷面敲擊，以取得橫斷面向之共振頻率。將此量測之兩項頻率帶入前述公式計算，即可直接求得該材料之動態卜松比。 This technique uses the wave propagation theory to obtain the axial resonant frequency of a one-dimensional solid circular rod and the guided wave theory to obtain its cross-sectional resonant frequency. A parameter of modified shape factor is obtained through regression of data from numerical analysis, and then used to get the required mathematical equation for calculation of dynamic Poisson’s ratio. Many techniques can be used to measure the axial and cross-sectional resonant frequencies of a solid round bar. In this patent application, the commercialized impact-echo method was adopted for illustration. In the experiment, the axial resonant frequency was obtained through the axial impact and the cross-sectional resonant frequency was obtained by the impact on the middle lateral surface of round rod. By substitution of these two resonant frequencies into the above-mentioned equation, the dynamic Poisson’s ratio of material can be obtained directly.

備註

本部(收文號1060004807)同意該校106年1月16日臺科大研字第1060100346號函申請終止維護專利

連絡單位 (專責單位/部門名稱)

技術移轉中心

連絡電話

02-2733-3141#7346

網址