焦散術在裂紋檢測上的應用

Caustics in the Application of Crack Measuring

謝宏榮(Hung-Jung Shei) ； 田代軍(Dai-Jun Tien)

《中華技術學院學報》 37期 (2007/12) Pp. 35-47

https://doi.org/10.7095/JCIT.200712.0035

摘要

本研究最主要係利用焦散術，以雷射當光源，受力後因材料試片裂縫附近產生局部應力集中，造成試片的厚度變化，導致其光折射率變化、入射光路程變化和光場方向的彎曲，而形成的陰影，從形成陰影的範圍和裂縫的長度成長情形，求出其應力擴大係數值，並可從應力擴大係數值預測試片發生斷裂的時間點。

關鍵字

折射 ； 裂縫 ； 焦散術

並列摘要

This research utilized the laser as light source and the so called ”Caustics” meathod to observe material stress near the crack. The stress concentration was occurred and the shadow was formed owing to its refraction change corresponding with thickness change of material. Observing the length and the growth of crack, the stress constants were calculated, and then the crack timing was to predict.

並列關鍵字

Refraction ； crack ； Caustics