材料中的缺陷，尤其是孔洞，對於材料的強度和可靠性具有重要的影響。在工程應用中，孔洞也是常見的設計方式，例如飛機上的窗戶、機身上的螺絲孔、連接孔…等。然而，傳統的失效應力計算方法可能無法準確預測含有缺陷的材料強度。因此，需要採用新的預測方法來解決這個問題。

有限破壞力學是一種相對新興的材料強度分析方法，可以預測含有缺陷材料的失效應力。它不僅可以模擬材料的裂紋擴展行為，還能處理已產生裂縫或未產生裂縫的情況。這種方法彌補了傳統破壞力學的不足。

本文介紹了缺陷對材料強度和可靠性的影響，特別是孔洞在工程應用中的普遍存在和應力集中問題。針對複合材料，本文提出了針對混合破壞模式的有限破壞力學方程式，以彌補傳統方法的不足。有限破壞力學方法可以提供準確的失效應力和裂紋長度預測，並且能夠處理各種形狀的缺陷結構。本文最後的範例也比較了不同孔洞形狀和纖維排向對抵抗負載的影響差異。

總體而言，有限破壞力學在預測含缺陷材料的強度方面提供了準確性，並在工程設計和分析中具有重要的應用價值。它能夠處理不同形狀的缺陷結構，並提供準確的失效應力和裂紋長度預測，有助於提高材料的可靠性和工程設計的效率。

Defects in materials, particularly holes, have a significant impact on the strength and reliability of the material. Circular holes are commonly found in engineering applications, such as round openings in aircraft windows. However, traditional methods for calculating failure stress may not accurately predict the strength of materials with defects. Therefore, new predictive methods are needed to address this issue.

Finite fracture mechanics is a relatively new approach for analyzing material strength, capable of predicting the failure stress of materials with defects. It can simulate crack propagation behavior and handle situations involving both existing and potential cracks. This method addresses the limitations of traditional fracture mechanics.

This paper discusses the influence of defects on the strength and reliability of materials, focusing particularly on the common occurrence of circular holes in engineering applications and the issue of stress concentration. For composite materials, a finite fracture mechanics equation is proposed to address mixed fracture modes, compensating for the limitations of traditional methods. Finite fracture mechanics provides accuracy in predicting failure stress and crack length, and it can handle various types of defect structures. The paper also includes examples comparing different hole shapes and fiber orientations in terms of load resistance.

In conclusion, finite fracture mechanics offers accuracy in predicting the strength of materials with defects and holds significant value in engineering design and analysis.

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