Comparison and Analysis between Non-destructive and Destructive Microscopic Testing for Investigation of Damage in Composite Laminates

本研究主旨在於使用積層板複材來模擬風力機組葉片的幾種不同型態且不同程度上的破壞，從幾種非破壞性的檢測方法來比較不同檢測方式上的優劣與檢測能力，最後利用破壞性之光學顯微微觀檢測方式來觀察積層板試片斷面與前面的非破壞性檢測結果做比較及驗證的工作，以利於檢測風力機組葉片發生破壞時，在選擇非破壞檢測之方法上能有參考的經驗與方法，就非破壞檢測之結果來判斷何種破壞，未來更進一步能夠以檢測結果來預測風力機組葉片之壽命。

本研究以小型積層板複合材料試片來模擬風力機組葉片，並於小型試片上製造出風力機組葉片較常發生的幾種破壞型態，如：衝擊破壞、扭轉破壞，及積層板與板之間的膠合破壞；在衝擊與扭轉破壞方面，能準確製造出所需的內部破壞規模後，便能以不同之非破壞檢測方式來做出比較；在膠合破壞這方面，則需先製作出膠合積層板式試片，將試片以剪力與拉伸來造成膠合處的破壞，而後再以非破壞檢測方式來檢測。

本研究所使用之非破壞檢測設備為超音波檢測與X-Ray照相探傷兩種，此兩種檢測皆為非破壞檢測但由於檢測原理上不相同，在檢測之能力與結果上亦有所差異，本研究將這兩種方式應用於檢測上述幾種較典型的風力機組葉片破壞方式，並相互比較其檢測方式上的優劣與檢測能力上之限制，最後，再以破壞性的光學顯微鏡檢測含有破壞之試片斷面，來驗證前面兩者之非破壞檢測結果是否準確，並解此掌握非破壞檢測方式之能力。

Small-scale specimens of composite laminations approximated to blades of wind power generator in this study, and several kinds of fracture mode occurred frequently on wind power blades were made on these specimens, including impact fracture, torsion fracture and the adhesive-bonded fracture between laminations and laminations. In the cases of impact fracture and torsion fracture, we can control the fracture scale, after that, to detect these fractures by using different NDT methods. In adhesive-bonded fracture case, first we should make some adhesive-bonded specimens and produce fracture in adhesive-bonded position with torsion and tensile tests. And then we can investigate damage by NDT methods.

Two NDT methods, Ultrasonic and X-radiography testing, were used in this study. Both of them are NDT methods, but their investigation mechanisms aren’t the same to lead to different testing results and measured abilities. We apply these two testing methods to detective several typical fractures which occurred in wind power blades. Then we compared these testing methods to find out their advantages, disadvantages and testing methods’ limitations. Finally, in order to prove the results’ accuracy, we used destructive optical microscope testing to detect these fractures in specimens. By above experiments we can accomplish a better utilization of the NDT methods.