金屬板中基于線性超聲相控陣列的損傷檢測研究

崔媛智，李 默

(江蘇大學 土木工程與力學學院，江蘇 鎮江 212013)

金屬板中基于線性超聲相控陣列的損傷檢測研究

崔媛智，李 默

(江蘇大學 土木工程與力學學院，江蘇 鎮江 212013)

金屬板結構由于在使用過程中受到外界載荷作用極易產生缺陷，而目前對結構初期損傷的實時動態監測仍存在一定困難。超聲相控陣陣列檢測技術不僅具有較高靈敏度，還具有對損傷進行動態聚焦、提升檢測信號信噪比和損傷成像分辨率等優點。通過對線性相控陣列參數進行優化設計，結合Lamb波頻率調諧理論，使用頻散效應弱的單一S0模態Lamb波，應用相控陣逐點掃描算法，通過仿真和實驗兩種手段針對板中貫穿刻槽損傷進行精確定位并成像，結果顯示，該算法可對損傷所在方位及走向做出判斷，得到較高質量的損傷評估檢測信息。為各類大型板狀結構長期穩定工作提供理論指導和實驗支持。

線性超聲相控陣；S0模態；陣列參數優化；損傷成像

AbstractThe structure of the metal plate is easy to produce defects in the process of external load. At present, there are some difficulties in the real-time dynamic monitoring of the initial structure damage. Ultrasonic phased array array detection technology not only has high sensitivity, but also has the dynamic focus on the damage, and it can also enhance the detection signal’s signal-noise ratio and the damage imaging resolution and so on. By optimizing the parameters of the linear phased array and combining the Lamb wave frequency tuning theory, a single S0 modal Lamb wave with weak dispersion effect is used, and the phased array point-by-point scanning algorithm is adopted. By means of phased array point-by-point scanning algorithm, the damage and localization of the penetrating hole in the plate are simulated and experimented. Results show that the algorithm can judge the orientation and direction of the damage and get the information of high quality damage assessment. Which provides theoretical guidance and experimental support for long-term stability of large-scale plate-like structures.

Keywordslinear ultrasonic phased array;S0mode; array parameter optimization; damage imaging

壓電超聲相控陣由若干相互獨立的壓電元件在空間按一定方式排列組成，其激發的超聲波可在空間干涉形成具有特定指向性和聚焦性的波束。按一定規則和時序對各陣元進行激發，使其發射的超聲波累加形成一個新的波陣面，以達到改變換能器空間排列形式的效果，從而改變換能器陣列輻射波束的具體指向[1]。該技術被廣泛應用于土木、軍事、科學和醫學等多個領域[2-4]。隨著近年超聲波理論和先進傳感技術、通訊技術以及快速數據處理等相關技術的迅速發展，相控陣技術在結構健康監測中得到了越來越廣泛的應用。……