32〇6§ 332〇6§ 3
'發明説明 A7 B7 (/ ) 本發^月係關於—種以量測暫態彈性波決定混凝土彈性常 强二ί—鋼珠撞擊物體表面產生擾動’此擾動能量以 波^形式由撞擊點向外擴散傳播，並使用兩個可量測試 面^向位移（在發明説明、圖示、及申請專利範圍内所 的橫向位移是指與待測試體表面切線方向平行的位 而^向位移是指與試體表面切線方向垂直的位移）訊號 ^了、測器’在不同的距離紀錄表面波動訊號，由此二訊號找 ^縱波$雷利波的延遲時間，而決定縱波與雷利波波速，配 、ϋ知密度，可計算試體之彈性常數。此方法具有非破壞性 點’只要所量測試體尺寸夠大，可不受標準尺寸試體的 制’對於現成結構物之缺陷檢測具有極大助益，但彈性波 所引起之應變量極小，故所量得結果應視為混凝土在低應變 下之彈性常數。 m In n HI ^^^1 -i^i ml . 叫、樂 (請先閱讀背面之注意事項再填寫本頁) 經濟部中夬棣準局員工消費合作社印製 現行量測材料彈性常數的方法有： 1. 對於金屬材料，以單軸拉伸及扭轉試驗測量材料之應力_ 應變關係而得楊氏係數(Y〇ung‘s Modulus)與剪力係數 (Shear Modulus)，此法需要求標準試體，由於在量測過程 中施力緩慢，可視為一靜態彈性常數的量測法。 2. 以超音波測量材料之縱波與橫波波速，配合質量密度的量 測，可計算材料之彈性常數或楊氏係數與剪力係數，此法 所量得數値為動態彈性常數，其値略大於靜態彈性常數。 3. 對於較複雜的材料如混凝土，一般以圓柱形標準試體施以 壓力試驗，可測量楊氏係數與柏松比(p〇isson’s rati〇)之靜 態値。 4. 另在混凝土材料亦可由一矩形試體之振動頻率計算其動 態材料常數，動態楊氏係數可以混凝土的縱向或橫向辰動 頻率計算，動態剛性係數可以扭曲頻率計算。' 在非破壞檢測技術中，以彈性波理論為基礎的，除了超 音波法外，尚包括音射法(Acoustic Emission)及暫態波法。音 射法的功能在於監視物體内部缺陷擴張情況，所量測之彈性 波是發自於物體内部微小t縫產生時所繹放的能量，是一種'Description of the invention A7 B7 (/) This article is about-a kind of measurement of transient elastic waves to determine the elastic strength of concrete II-steel balls hit the surface of the object to generate disturbances "This disturbance energy in the form of wave ^ from the impact point outward Diffusion propagation, and use two measurable test surface displacements (in the description, illustration, and patent application, the lateral displacement refers to the position parallel to the tangent direction of the surface of the body to be tested and the displacement refers to the The vertical displacement of the tangent direction of the surface of the test body) signal ^, the detector 'records the surface fluctuation signal at different distances, from which the second signal finds the delay time of ^ longitudinal wave $ Rayleigh wave, which determines the longitudinal wave and Rayleigh wave velocity. Ϋ Know the density and calculate the elastic constant of the specimen. This method has a non-destructive point 'as long as the size of the measured body is large enough, it can not be manufactured by the standard size body'. It is of great help to the defect detection of ready-made structures, but the strain caused by the elastic wave is very small, so The measured result should be regarded as the elastic constant of concrete under low strain. m In n HI ^^^ 1 -i ^ i ml. Call, please (please read the precautions on the back before filling in this page) The method of printing the current measurement material elastic constants by the Employee Consumer Cooperative of the Ministry of Economic Affairs of the Ministry of Economic Affairs There are: 1. For metal materials, the uniaxial tensile and torsional test measures the stress_strain relationship of the material to obtain the Young's coefficient (Y〇ung's Modulus) and the shear coefficient (Shear Modulus). This method requires standards The test body can be regarded as a static elastic constant measurement method because the force is applied slowly during the measurement. 2. Ultrasonic measurement of the longitudinal and transverse wave velocity of the material, combined with the measurement of mass density, can calculate the elastic constant or Young's coefficient and shear coefficient of the material. The value measured by this method is the dynamic elastic constant, which is abbreviated Greater than the static elastic constant. 3. For more complex materials such as concrete, a cylindrical standard specimen is generally subjected to a pressure test, which can measure the static value of the Young's coefficient and the Poisson's rati ratio. 4. In the case of concrete materials, the dynamic material constant can also be calculated from the vibration frequency of a rectangular specimen. The dynamic Young's coefficient can be calculated from the longitudinal or lateral dynamic frequency of the concrete, and the dynamic stiffness coefficient can be calculated from the twisted frequency. 'In the non-destructive detection technology, based on the elastic wave theory, in addition to the ultrasonic method, it also includes the acoustic emission method (Acoustic Emission) and the transient wave method. The function of the acoustic method is to monitor the expansion of defects inside the object. The measured elastic wave is the energy released when the small t-slit inside the object is generated. It is a kind of energy
本紙張尺度適用中國國家標準（CNS ) A4规格（21〇.< 37公看I 訂 A7 A7 經濟部中央標準局®C工消費合作杜印製 ^ ^________B7 五、發明説明（z) ί動式ί量測··。超音波法在金屬材料方面的檢測已有相當時 日’且$展了許多成熟技術。但對於混凝土材料的檢測，受 材ΐ的複雜性，仍停留在混凝土的縱波波速的量測，企 圖由縱波波速評斷混凝土的強度及均勻性。近年來，暫態波 ^逐漸地受到重視，其中在敲擊回音法(Impact_ech〇 Meth〇d) 中’使用一鋼珠敲擊混凝土表面產生彈性波入射混凝土内， ^錐开y波動感測益·測量表面垂直位移，由所接收訊號的頻 譜中，縱波的回音頻率與試體的振動模態頻率，找出試體的 縱波波速及缺陷之所在。 >混凝土内含骨材，孔隙及鋼筋，彈性波在其内傳播容易 衰減及造成頻散，對於彈性波速的量測比在金屬材料中的量 測增加一些困難，準確度亦較低。目前超音波量測混凝土縱 波波速是以波前(wave-front)的傳輸時間為依據，而敲擊回音 法巧以觀察頻譜中特殊頻率値，在文獻上亦鮮少見到與混凝 土核"波波_相關的里測方法，因而應用彈性波的量測決定混 凝土材料常數的方法一直未被建立起來。雖然在已知試體厚 度的前題下(如板之厚度），敲擊回音法可測得縱波波速，但 對於橫波波速的量測,尚有不足之處，因此法只利用到訊號的 頻率訊息，而忽略了其他特徵。事實上，一個波動訊號包含 著許多特徵：傳輸時間、反射、繞射、折射、相位、頻散： 頻率等，對於不同類型的缺陷所獲得的檢測訊號，應^出最 為可靠的訊號特徵加以處理。同時敲擊回音法使用之感測 器，只可測量試體表面的縱向位移，而忽略了橫向位移能 提供訊噪比値(SNR)更高的訊號。 本發明之動機乃鑑於敲擊回音法在現場量測之方便性， 但卻局限於所使用之感測器及訊號分析的工具，而盔法達到 量測物體材料常數的功能，故針對現行敲擊回音法&不足作 改進。仍然採用鋼珠敲擊產生暫態波波源，但改以量測物體 表面的橫向位移訊號(敲擊回音法是量測物體表面的縱向位 移訊號），對訊號的處理也不局限於頻率的分析，而是在時 間域處理訊號直接計算縱波與雷利波之延遲時間。配合;、昆凝 土已知的密度，達到量測混凝土材料常數的目的。σ 冬紙張尺度遑用中國國家標準.（CNS )A4規格（210 x 2t)7公f ^ ^裝 訂 ^線 (請先閱讀背面之注意事項再填寫本頁) 320683 Λ： 經濟部中央標準局員工消費合作社印袈 發明説明（3 本發明之方法，它的優點是 物的單—表面測量其材料常數，而不必知道結 ί的S3:且是一種非破壞性的檢測方法，可保持結梢 面量測，所量得之結果可視為結構物 器之間局部區域之材料常數，若此 W變，則所量 物間過長或遭遇外力而產生局部破壞量各局部之材料性質的變化情形，藉 圖式之簡單説明 g—圖係一半無限域之表面受一垂直外力及其座標示意 圖。 係-鋼珠撞擊在—半無限域之表面所產生之縱向位移说號。 係-鋼珠撞擊在—半無限域之表面所產生之橫向位移说號。 $四圖係作為摺積（convolution)計算的兩橫向位移訊號。 S f 2 Ϊ積ΐ ϊ 2得之速度與距離(波源與第-感測器 =間）的關係’結構體為一半無限域。 第π f ί ί積計算所得之速度與距離(波源與第-感測器 <間）的關係，結構體為一平板。 ^七圖係為表1波動位移訊號量測之實驗設置 第八圖係表面橫向位移訊號之實驗量測結果與理論計算値 之比較。 第九圖係表面橫向位移訊號。 y十圖係將表面橫向位移之初始訊號經濾波後之結果。 第十一圖係在不同距離所測得之表面縱波之傳輸時間及其 ，性回歸近似之結果，量測之表面為板之上表面。、 第十二圖係在不同距離所測得之表面縱波之傳輸時間及其 ，性回歸^似之結果，量測之表面為板之下表面。、 第十三圖實驗量得之雷利波波速與距離（第一感測器與 之間）之間的關係 狀原 . I » II . I----------批衣—— . ( (請先閱讀背面之注意事項再填寫本頁) 訂 線 ΜΛ·浓尺度4;丨丨中阁:句b袁.來|_，NS ) Λ·!畎洛 'I') ' ：') 1 ^ % A五、發明说明（夺） 經濟部中央標隼局員工消費合作社印11 對於上述問題的根本解決之道，需從 八 底了解-半無限域之表面受垂直外nim最=法。對於-半 一垂直外力所產生炙波動現象，理論上獲 $ (G_ function)之解析解（書籍:Kad F Graff^m^ dastic^Uds'pp.343-37^75年）。對任—形狀之波源函數 理淪汛唬，可將格林函數解與波源時間函數作招精 得。，在進2理論$析前，需對於一半無限域之座ii-明^ 定我二如弟二圖中z所代表之箭頭表深度方向座標，r所 表之箭頭表徑度方向座標，Θ代表角度，Q之箭頭代表作用 外力之大小。鋼珠敲擊所產生之波源函數可以sml.5函 半週期近似（期刊：Wu，T,T.，Fang, I,S., Liu, G,Y., and Ku。， M.-K. Determination of Elastic Constants of a Concrete Specimen Using Transient Elastic Waves；5 Journal of Acoustic Society of America:兕⑷^42-2^8]995 )，以此波源函數計算士得 之理論訊號中，其表面位移訊號之垂直分量如第二圖所示， 此圖中之縱座標與橫座標之標示為一無因次化的量，且使用 波源之持續時間經無因次化後之値，其寬度為〇3倍之橫座 標刻度。在縱橫座標之標示中符號t為時間、Ct為試體之橫 波波速、r為波源與感測器之間的距離、材料之剪力係 數、〜為深度方向之位移分量，訊號上標示著p之箭頭表縱 波到達之時間位置，R表雷利波到達之時間位置。第三圖為 表面位移訊號之水平分量，圖中Ur為徑度方向之位移分量， 其餘符$所代表之意義與第二圖中之同一符號之意義相 同。由弟一、二圖之訊號可歸納出一些波動特性。 1·表面點波源所產生的暫態波中，縱波總是以最快的速度向 外傳播’因而在表面所接受的波動訊號中，最早到達的是 縱波波前，但其所引起的橫向位移遠大於縱向位移。基於 縱波的此點特性，記錄縱波波前之橫向位移訊號，對於決 $縱波之傳輸時間的決定應可提供一更精確的結果。 2. 橫波波前並未在訊號中造成一明顯的振幅變化，故欲直接 從訊號中量測橫波波速並不容易。 3. 表面點波源所產生的表面擾動中，由雷利波攜帶著大部汾 的能量’而且其衰減速率比縱波與橫波的衰減速率慢，故 在與波源相當距離的表面上所接收的訊號中，其波形主要 由雷利波所主導。 (請先閱讀背面之注意事項再填寫本頁} -裝' 訂 線 經濟部中央樣準局員工消费合作社印袈 320683 五、發明説明（5 ) 橫向位移訊號與縱向位移訊號的另一不同點在於：縱 1位移訊號在雷利波經過之後即恢復平靜狀態，但橫向位 f訊號於雷利波之後則維持一振幅持續下降的狀態，逐 趨近於零。 所 综合上述表面波動的四點特性，可設計兩點量測彈性 波速的方法： 叹 1_巧於縱波，可在同一表面記綠表面位移訊號之波前的傳 B寺間，但以量測橫向位移訊號為佳。 2.，利波具有不發生頻散的特性，對於兩組相似的時間域訊 巧可以交互相關函數計算其傳輸時間。但事實上，仍有部 ^縱波與橫波訊號夾雜在雷利波波形内，他們的影響將隨 著距離的增加而減弱。本發明以理論分析所計算之雷利 速與距離的關係，找出實際量測時波源與感測器之間的距 離限制。 實際上做為摺積計算的兩訊號，其長度必須有限。由於 目的在於計算雷利波的延遲時間，如第四圖所示，訊號只取 到雷，波波形為止，圖中81與52代表兩個橫向位於感測器， ri為第一感測器與波源之間的距離，d是兩感測器之間的距 離。逐次改變η，計算其相對的波速値，結果如第五圖所示， 此圖之縱座標與橫座標之標示為無因次化的量，其中cRg 實際之雷利波波速、c為計算之波速，tc為波源之持續時 間，其餘符號之定義如前面各圖中之定義。此圖顯示當 ri/CRTc大於1，以摺積法所計算之雷利波速度與實際値之^ 異小於0.005，故在實驗量測時應先經由此評估波源與感測 器之間的距離。 ~ 以上雷利波量測法的設計乃針對一半無限域之結構，對 於一無窮平板而言，波動能量將由板底面反射回來，再次干 擾板之上表面，因而欲使用上述之雷利波量測法於平板結 構，需另進行理論分析。分析方法如前所述，其結果如第六 圖所示，當π/CrTc大於1 ’計算之雷利波速度與實際値之 差異小於0.01。誤差增加是因為由下表面反射的波動能量亦 影響上表面之位移，但對於混凝土的波速量測，此誤差値是 在可接受的範圍内。 f請先閣讀背面之注意事項再填寫本頁) .裝· 訂 P氏浪尺度嘁屮'卜陶莕€嘌.达 ·This paper scale is applicable to the Chinese National Standard (CNS) A4 specification (21〇. ≪ 37 public viewing I set A7 A7 Central Ministry of Economic Affairs ® C industrial and consumer cooperation du printing ^ ^ ________ B7 V. Invention description (z) ί 动Type measurement ... Ultrasonic method has been used in metal materials for quite a long time and has developed many mature technologies. However, for the detection of concrete materials, due to the complexity of the material, it still stays in the longitudinal wave of concrete The measurement of wave velocity attempts to judge the strength and uniformity of concrete from the longitudinal wave velocity. In recent years, the transient wave has gradually been paid attention to, among which the use of a steel ball to strike the concrete in the impact echo method (Impact_ech〇Meth〇d) The elastic wave generated on the surface enters the concrete, and the measurement of the vertical displacement of the surface is measured by the cone-shaped y wave. From the frequency spectrum of the received signal, the echo frequency of the longitudinal wave and the vibration modal frequency of the specimen find the longitudinal wave velocity of the specimen And defects. ≫ Concrete contains aggregates, pores and steel bars, elastic waves propagate in it and it is easy to attenuate and cause frequency dispersion, the measurement of elastic wave velocity is increased by one compared to the measurement in metal materials Some difficulties are difficult, and the accuracy is also low. At present, the ultrasonic measurement of the longitudinal wave speed of concrete is based on the wave-front transmission time, and the percussion echo method is used to observe the special frequency value in the spectrum. It is rare to see the internal measurement method related to the concrete core "wave wave", so the method of determining the material constant of the concrete using the measurement of the elastic wave has not been established. Although under the prerequisite of the known thickness of the test body (such as the plate Thickness), the percussive echo method can measure the longitudinal wave velocity, but there are still deficiencies in the measurement of the shear wave velocity, so the method only uses the frequency information of the signal and ignores other characteristics. In fact, a fluctuating signal Contains many characteristics: transmission time, reflection, diffraction, refraction, phase, frequency dispersion: frequency, etc. For the detection signals obtained by different types of defects, the most reliable signal characteristics should be processed to deal with. At the same time, the echo method The sensor used can only measure the longitudinal displacement of the surface of the test body, while ignoring the lateral displacement can provide a signal with a higher signal-to-noise ratio (SNR). The motivation of the present invention is to The convenience of percussion echo measurement in the field, but it is limited to the sensors and signal analysis tools used, and the helmet method achieves the function of measuring the material constant of the object, so it is insufficient for the current percussion echo method & For improvement, the steel ball is still used to generate the transient wave wave source, but the lateral displacement signal on the surface of the object is measured (the knocking echo method is to measure the longitudinal displacement signal on the surface of the object), and the processing of the signal is not limited to frequency Analysis, but the signal is processed in the time domain to directly calculate the delay time of the longitudinal wave and the Rayleigh wave. The density of the Kunming soil is known to achieve the purpose of measuring the constant of the concrete material. Σ winter paper scale uses Chinese national standards . (CNS) A4 specification (210 x 2t) 7 male f ^ ^ binding ^ line (please read the precautions on the back before filling in this page) 320683 Λ: Description of inventions printed by the Employee Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs (3 copies The method of the invention has the advantage of measuring the material constant of the single-surface of the object without knowing the S3 of the knot: and is a non-destructive detection method, which can maintain the measurement of the knot tip surface. The result can be regarded as the material constant of the local area between the structural objects. If this W changes, the amount of the object is too long or encounters an external force to produce a local damage. The local material properties change. g—The graph is a schematic diagram of a half external surface subjected to a vertical external force and its coordinates. System-The longitudinal displacement of the steel ball impacting on the surface of the semi-infinite field. System-the horizontal displacement of the steel ball impacting on the surface of the semi-infinite domain. $ Four graphs are two horizontal displacement signals calculated by convolution. The relationship between the velocity of S f 2 Ϊproduct 1 ϊ 2 and the distance (between the wave source and the first sensor) = the structure is a half infinite field. The relationship between the speed and distance (between the wave source and the first sensor) calculated by the product of π f ί ί is a flat plate. ^ The seven graphs are the experimental settings for the measurement of the wave displacement signal in Table 1. The eighth graph is the comparison between the experimental measurement results of the surface lateral displacement signal and the theoretical calculation value. The ninth figure is the surface lateral displacement signal. y10 is the result of filtering the initial signal of the lateral displacement of the surface. The eleventh figure is the propagation time of the surface longitudinal waves measured at different distances and the results of the linear regression approximation. The measured surface is the upper surface of the board. The twelfth figure is the transmission time of the surface longitudinal waves measured at different distances and the results of the linear regression. The measured surface is the surface under the board. , The relationship between the Rayleigh wave velocity and distance (between the first sensor) measured by the experiment in Figure 13 is the original. I »II. I ---------- Baiyi— — ((Please read the precautions on the back before filling in this page) Stranding ΜΛ · Nonscale 4; 丨 丨 Cabinet: 句 b 袁. 来 | _, NS) Λ ·! 畎 洛 'I') ': ') 1 ^% A V. Description of the invention (winning) The Ministry of Economic Affairs, Central Standard Falcon Bureau Employee Consumer Cooperative Seal 11 For the fundamental solution to the above problems, you need to understand from the bottom of the bottom-the surface of the semi-infinite domain is most affected by vertical nim = law. For the semi-vertical force generated by the vertical external force, the theoretical analytical solution of $ (G_function) is obtained (book: Kad F Graff ^ m ^ dastic ^ Uds'pp.343-37 ^ 75). For the wave source function of Ren-shape, it is possible to refine the Green function solution and the wave source time function. Before entering the 2 theoretical analysis, it is necessary to determine the coordinates of the arrow in the depth direction of the half of the infinite field ii-ming ^ as shown in the diagram of z in the second figure of the second brother, and the arrow in the direction of the radius of the arrow in the table of r, Θ Represents the angle, and the arrow of Q represents the magnitude of the applied external force. The wave source function generated by the steel ball knocking can be approximated by the semi-period of the sml.5 function (Journal: Wu, T, T., Fang, I, S., Liu, G, Y., and Ku., M.-K. Determination of Elastic Constants of a Concrete Specimen Using Transient Elastic Waves; 5 Journal of Acoustic Society of America: 兕 ⑷ ^ 42-2 ^ 8] 995), which uses the wave source function to calculate the vertical displacement signal in the theoretical signal of STO The component is shown in the second figure. The vertical and horizontal coordinates in this figure are marked as a dimensionless quantity, and the duration of the use of the wave source after the dimensionless dimension is 3 times the width. Horizontal scale. In the vertical and horizontal coordinates, the symbol t is time, Ct is the shear wave velocity of the sample, r is the distance between the wave source and the sensor, the shear coefficient of the material, ~ is the displacement component in the depth direction, and the signal is marked with p The arrow indicates the time position of longitudinal wave arrival, and R indicates the time position of Rayleigh wave arrival. The third picture is the horizontal component of the surface displacement signal. In the picture, Ur is the displacement component in the radial direction. The rest symbol $ represents the same meaning as the same symbol in the second diagram. The signals of the first and second pictures of the younger brother can be summarized into some fluctuation characteristics. 1. Of the transient waves generated by the surface point wave source, the longitudinal wave always propagates outward at the fastest speed. Therefore, among the wave signals received by the surface, the earliest arrival is the longitudinal wave front, but the lateral displacement caused by it Far greater than the longitudinal displacement. Based on this characteristic of the longitudinal wave, recording the transverse displacement signal of the longitudinal wave front should provide a more accurate result in determining the transmission time of the longitudinal wave. 2. The shear wave front does not cause a significant amplitude change in the signal, so it is not easy to measure the shear wave velocity directly from the signal. 3. In the surface disturbance generated by the surface point wave source, most of the Fen energy is carried by the Rayleigh wave and its attenuation rate is slower than that of the longitudinal and transverse waves, so the signal received on the surface at a considerable distance from the wave source Among them, its waveform is mainly dominated by Rayleigh waves. (Please read the precautions on the back and then fill out this page) -Installation '碈 320683, Employee's Consumer Cooperative of the Central Prototype Bureau of the Ministry of Economics 320683 V. Description of Invention (5) Another difference between the horizontal displacement signal and the vertical displacement signal is : The vertical 1 displacement signal returns to a calm state after passing through the Rayleigh wave, but the lateral position f signal maintains a state in which the amplitude continues to decrease after the Rayleigh wave, and gradually approaches zero. The four-point characteristics of the above-mentioned surface fluctuations are integrated , Two methods for measuring the elastic wave velocity can be designed: Suppose that the longitudinal wave can record the wavefront of the green surface displacement signal on the same surface and pass between the B temples, but it is better to measure the lateral displacement signal. The Li wave has the characteristics of no dispersion, and for two sets of similar time domains, the correlation time can be used to calculate the transmission time. But in fact, there are still some ^ longitudinal wave and transverse wave signals mixed in the Rayleigh wave waveform, their The influence will weaken as the distance increases. The present invention uses theoretical analysis to calculate the relationship between the Rayleigh velocity and the distance to find the distance limit between the wave source and the sensor during actual measurement. The two signals used for the calculation of convolution must have a limited length. Since the purpose is to calculate the delay time of the Rayleigh wave, as shown in the fourth figure, the signal only takes the thunder and wave waveforms. 81 and 52 in the figure represent two Located laterally in the sensor, ri is the distance between the first sensor and the wave source, and d is the distance between the two sensors. Change η successively to calculate the relative wave velocity value, the result is shown in the fifth figure, The vertical and horizontal coordinates of this figure are dimensionless quantities, where cRg is the actual Rayleigh wave velocity, c is the calculated wave velocity, tc is the duration of the wave source, and the remaining symbols are defined as in the previous figures Definition. This figure shows that when ri / CRTc is greater than 1, the difference between the Rayleigh wave velocity calculated by the convolution method and the actual value is less than 0.005, so during the experimental measurement, the difference between the wave source and the sensor should be evaluated first. ~ The above Rayleigh wave measurement method is designed for the structure of half of the infinite field. For an infinite plate, the wave energy will be reflected back from the bottom surface of the plate and interfere with the upper surface of the plate again, so I want to use the above Rayleigh Wave measurement method on flat structure Requires another theoretical analysis. The analysis method is as described above, and the results are shown in the sixth figure. When π / CrTc is greater than 1 ', the difference between the calculated Rayleigh wave velocity and the actual value is less than 0.01. The wave energy reflected by the surface also affects the displacement of the upper surface, but for the measurement of the wave speed of concrete, this error value is within the acceptable range. F Please read the precautions on the back before filling this page). Shi's wave scale 嘮 屮 'BU Tao Xing
經濟部中央標準局員工消費合作社印梵 、依據上述設計方法，進行實際量測以驗證可行性。所使 用之試體為一以尺寸為60cm X 55cm X 13cm之混凝土板，其 水灰比為0.44，授拌後灌模的同時使用震動台震動及重力g 用丨因而發生骨材向下沈澱的現象，可預期此混凝土板下表 面之波速應大於上表面之波速。 本發明所提出的波速量測方法依然使用鋼珠敲擊混凝土 表面為波源，此波源所引致之表面縱波波前的橫向位移大於 縱向位移，因而利用兩可量測橫向位移之波動感測器測量表 面位移訊號。。第七圖為實驗設置圖，①表敲擊之鋼珠，圖中 波動感測器②③接收到訊號可經由前置放大器④④放大 後，由數位示波器®記錄。首先比對量測訊號與理論訊號， ，严如第八®所示，圖中實線表實驗量測訊號，虛線為理論 訊號。除了實驗訊號在雷利波之後有些微振盪情形外，兩者 頗為二致，但此振盪並不干擾縱波與雷利波延遲時間之量 測。貫驗上，為了更精確的測量縱波波前訊號，將重點放在 初始訊號的觀察，因而在記錄訊號時調低示波器之輸入範 圍，如此可增加解析度，如第九圖所示之縱軸上下線為〇 〇4 伏特及-0.04伏特。圖中標示p之箭頭位置表縱波波前到達 時間’ R表雷利波到達時間。另在縱波到達之前，訊號並非 完全的^靜而仍具有些微振幅，此乃示波器電子雜訊的干 擾，在實驗量測時無法避免。為了消除此雜訊的不利影響， 採用過濾的措施，可去除高頻的雜訊，並可增加解析度。本 發明中以一低通之線性相位有限衝擊濾波器(丨inear phase finite impulse filter)(書籍：Rodger E zieme wilUam H Trante and D. Ronald Fannin, "Signals and Systems: Continuous and discrete” pp. 363-379, 1983 )處理訊號所得結果如第十圖所 示，此圖之訊號是將縱波波前附近的訊號過濾後放大的結 果。明顯的，在圖中標示著p的位置上，訊號產生一陡峭的 爬:升，其振幅比在位置P之前的訊號都來得大，對照圖中橫 座標的時間刻度，P之位置的決定，其誤差應可在〇 5的 範圍内。 在作縱波波速量測時，逐次增加二感測器間的距離，分 別量測其縱波波前傳輸時間。首先在板之上長面所量測的結 果如第十一圖’感測器之間的距離從5ciii至丨7em，每次增 -----------裝 訂 線 • ί ί (請._无閱讀背面之注意事項再填寫本頁)Yin Fan, an employee consumer cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs, conducted actual measurements based on the above design methods to verify the feasibility. The test body used is a concrete slab with a size of 60cm X 55cm X 13cm, and its water-cement ratio is 0.44. After the mixing and pouring, the shaking table is used to shake and gravity g at the same time, so the aggregates precipitate downward Phenomenon, it can be expected that the wave velocity of the lower surface of this concrete slab should be greater than the wave velocity of the upper surface. The wave velocity measurement method proposed by the present invention still uses the steel ball striking the concrete surface as the wave source. The lateral displacement of the longitudinal wave front of the surface caused by this wave source is greater than the longitudinal displacement, so the surface is measured using two wave sensors that can measure the lateral displacement. Displacement signal. . The seventh picture is the experimental setup diagram, ① the steel ball struck, the wave sensor ②③ received signal can be amplified by the pre-amplifier ④④, and recorded by the digital oscilloscope®. First, compare the measurement signal with the theoretical signal, as shown in the eighth ®, the solid line in the figure shows the experimental measurement signal, and the dotted line is the theoretical signal. Except for the slight oscillation of the experimental signal after the Rayleigh wave, the two are quite the same, but this oscillation does not interfere with the measurement of the delay time of the longitudinal wave and the Rayleigh wave. In practice, in order to more accurately measure the longitudinal wave wavefront signal, the focus is on the observation of the initial signal, so when recording the signal, lower the oscilloscope's input range, so that the resolution can be increased, as shown in the vertical axis of the ninth figure The upper and lower lines are 〇04 volts and -0.04 volts. The position of the arrow marked p in the figure indicates the arrival time of the longitudinal wave front 'R indicates the arrival time of the Rayleigh wave. In addition, before the longitudinal wave arrives, the signal is not completely static and still has a slight amplitude. This is the interference of the electronic noise of the oscilloscope and cannot be avoided during the experimental measurement. In order to eliminate the adverse effects of this noise, filtering measures can be used to remove high-frequency noise and increase the resolution. In the present invention, a low-pass linear phase finite impulse filter (Book: Rodger E zieme wilUam H Trante and D. Ronald Fannin, " Signals and Systems: Continuous and discrete ”pp. 363 -379, 1983) The result of processing the signal is shown in the tenth figure. The signal in this figure is the result of filtering and amplifying the signal near the longitudinal wave front. Obviously, at the position marked p in the figure, the signal produces a Steep climb: rise, its amplitude is larger than the signal before the position P, according to the time scale of the horizontal coordinate in the figure, the error of the position of P is determined to be within the range of 〇5. When measuring, increase the distance between the two sensors one by one, and measure the longitudinal wave wavefront propagation time respectively. First, the measurement results on the long surface above the board are as shown in the eleventh figure. The distance between the sensors is from 5ciii To 丨 7em, increase each time ----------- binding line • ί ί (please._ fill in this page without reading the precautions on the back)
發明説明（7) Ϊ中，直線為線性回歸結果，其斜率即為波速，第 =了圖，在混凝土下表面量測之結果。所測得之縱波波速分 別為上表面4240m/s，下表面4602m/s。 同時亦對上下表面進行雷利波波速量測，兩感測器之間 勺距離為13cm與板厚度相同，鋼珠敲擊位置與第一感測器 ，間距離為5cm至22cm ’每次增加icm，量。結果如第十 二圖所tf之兩组數據(符號χ表上表面的量測結果；〇表下 ^面的量測結果）。分別平均兩組數據得雷利波波速為：上 2303 ± 36,2m/s、下表面 2548 ± 28.4ni/s。 如則所述，受重力影響，骨材向下沈澱，因而下表面之彈性 波速大於上表面之彈性波速。 於縱S皮與雷利波波速已知，橫波波速的計算就可帶入 雷利波方程式(2-^-)2=4(l-S.)i(i_S)i , Cj· CL CT 求得橫波波速為上表面cr= 2513m/s、下表面cv= 2792m/s 〇 又彈性常數與彈性波速滿足下列關係 τ』Wm/s λ + 2Μ σ = μ Ρ γ = ρ 先· 閱 a 背 Γ& 之 意 % 再 填 寫 本 f 裝 訂 Q2 經濟部中央橾华局員工消費合作让印货 A、芦為Lame constants，且楊氏係數五與柏松比^可 表示成 //(32 + 2//) 又 -:- v =---- λ-\- μ 2{λ^ μ) 依次計算所的之値為上表面£^37.67GPa、#0.229，下表 面五=45_74GPa、β0.209。 線 ;'NS ! · ：1〇 ΛDescription of the invention (7) In Ϊ, the straight line is the linear regression result, and the slope is the wave velocity. The measured longitudinal wave velocity is 4240m / s on the upper surface and 4602m / s on the lower surface. At the same time, the Rayleigh wave velocity measurement is also performed on the upper and lower surfaces. The spoon distance between the two sensors is 13cm and the thickness of the board is the same. The distance between the steel ball knocking position and the first sensor is 5cm to 22cm. ,the amount. The results are as the two sets of tf data shown in the twelfth figure (symbol χ indicates the measurement result on the upper surface; 〇 indicates the measurement result on the lower surface). The average of the two sets of data is the Rayleigh wave velocity: upper 2303 ± 36,2m / s, lower surface 2548 ± 28.4ni / s. As mentioned above, under the influence of gravity, the aggregates settle down, so the elastic wave velocity of the lower surface is greater than the elastic wave velocity of the upper surface. Since the longitudinal S skin and Rayleigh wave velocity are known, the calculation of the shear wave velocity can be brought into the Rayleigh wave equation (2-^-) 2 = 4 (lS.) I (i_S) i, Cj · CL CT to obtain the shear wave The wave velocity is cr = 2513m / s on the upper surface and cv = 2792m / s on the lower surface. The elastic constant and the elastic wave velocity satisfy the following relationship. Τ'Wm / s λ + 2Μ σ = μ Ρ γ = ρ First, read a back Γ & Please fill in this f again. Binding Q2 The consumption cooperation of the Central Central Bureau of Economic Affairs of the Ministry of Economic Affairs allows the printed goods A and Lu to be Lame constants, and the Young's coefficient V and the Bosson ratio ^ can be expressed as /// (32 + 2 //) And-:-v = ---- λ-\-μ 2 {λ ^ μ) The values calculated in turn are the upper surface £ ^ 37.67GPa, # 0.229, the lower surface five = 45_74GPa, β0.209. Line; 'NS! ·: 10 Λ