2014遠東大會特邀報告

運用無損評估技術進行結構完整性管理

克里斯丁·鮑勒

薩爾大學無損檢測與質量保障首席教授

弗朗霍菲無損檢測研究所所長（薩爾布呂肯/德累斯頓）

Managing StructuralIntegrity through Non-Destructive Evaluation

Christian Boller

Chair of NDT & Quality Assurance, SaarlandUniversity, Saarbrücken/Germany

Fraunhofer IZFP, Saarbrücken/Germany

結構完整性在工程領域具有舉足輕重的地位。毫無疑問，如果沒有結構完整性管理,工程質量安全將得不到根本保障。不論是設計還是制造行業，恰當的質量保障都是必須的。在制造和裝配工序中運用無損檢測技術（NDT），已經取得了顯著成果。而NDT并不局限于制造和裝配工藝中的缺陷檢測，它也廣泛適用于如壓力、強度、硬度、空隙、濕度、密度等物理參量的檢測，甚至能達到微觀量級。目前隨著低成本、高性能傳感技術的普及以及對工程結構性能的需求日益提升，NDT技術已經成為檢驗制造品質的主要技術方法。在生產-裝配作業鏈中，NDT的存在并非總是顯而易見，因為NDT技術工藝已經完全融入其中，作為一種物理控制參數成為制造過程中不可或缺的組成部分。

   隨著時間的推移，在役的工程結構會出現老化并導致損傷。這個老化過程是不可避免的，具有一定的隨機性，必須對它進行有效管理，確保結構的安全性不受影響。此前不太可能實現的損傷累積評判、結構老化跟蹤研究，如今借助成本不斷降低、計算能力逐漸增強的新型傳感器技術都得以實現。在NDT技術的基礎上，結合其他預測方法和工具，結構的老化過程已能夠被預測。這將有助于“獨立的”評估一個工程結構的壽命，同時也為管理這些工程結構的狀態修和工作壽命優化提供了可能。

   基于所述問題，本報告將闡述不同材料結構的NDT運用管理，從目前廣為人知的金屬材料開始，逐漸過渡至纖維（如碳纖維）復合材料、礦物材料（如混泥土）。雖然目前對礦物材料的損傷機理所知不多，但可以應用金屬領域一些相似的損傷容限原理，同時最近的新興NDT檢測技術也以期被有效利用。

Structuralintegrity is paramount in the engineering profession. Without this not beingguaranteed there is no justification for engineering at all. For whatever isdesigned or built the appropriate quality has therefore to be warranted.This is significantly achieved through non-destructive testing (NDT) beingapplied in the manufacturing and assembly process. NDT is not limited todetecting flaws during a manufacturing and assembly process only. Stresses andstrength, hardness, porosity, humidity or density are parameters widelyconsidered by NDT too and this even down to the micro scale. The ability ofobtaining sensor technology at a decreasing cost and the ambition in enhancingan engineering structure’s performance has allowed NDT to become a majorelement in certifying manufacturing quality. This may not always becomeapparent along the manufacturing and assembly process chain since many of theNDT procedures have even become a part within the manufacturing process itselfin a way that NDT parameters are used as a physical control parameter duringthe manufacturing process.

Engineering structures in operationare due to age and hence to damage over time. This is an unavoidable process ofa stochastic nature that has to be managed such that safety of those structuresis never compromised. Again enhanced and emerging sensor technology provided ata continuous decrease in cost and being combined with an increase in computationpower does allow damage accumulation and hence ageing of structures to betracked in a way this has never been possible before. With additionalprognostic methods and tools ageing processes of structures can be predicted onthe basis of NDT techniques. This can help to ‘individually’ assess anengineering structure’s life, which opens opportunities to manage thosestructures’ maintenance on condition and to optimize their usage in terms ofoperational life at the same time.

Based on those management issues thepresentation will address structures made of different types of materialsstarting with metals as the material being known best at present and graduallymoving over to composite materials of a fibrous (i.e. CFRP) as well as amineral (i.e. concrete) basis, where the damaging mechanisms are less known butthe principle of damage tolerance can be applied similar to metals in caseadequate advantage of recent and emerging NDT technology can be taken.