本論文主要以強度-應力干擾理論（SSI）當作理論基礎，針對複合材料之強度退化，假設初始強度分佈與應力分佈為一常態分佈，並以強度退化的動態方程式去做蒙地卡羅模擬實際使用的情況下，殘留強度隨時間退化的現象，再進一步以Weibull Model和η Model去做嵌合，描述其行為並加以討論可靠度退化與複合材料之殘留強度分佈的變化。 接著依據第一階段應力施加的理論，去推出第二階段的強度退化之動態方程式，考慮以可靠度當作應力調整轉換點去做蒙地卡羅模擬時，可發現其二階段的轉換點會因應力施加順序的不同而有所差異，以高應力轉換成低應力來說，會出現一段近似無失效的現象，且這段近似無失效期會因高低應力的差距愈大而增大，依據此現象去推導出其近似無失效期（cycles），並以模擬數據加以比較其準確性。若進一步來做探討，只討論其轉換點1>R>0.99範圍，可將其水平視為保證期（即近似無失效期）。 This thesis mainly regards as the theoretical foundation with SSI. Strength degradation in view of composite, the supposition original strength distribution and the stress distribution are a normal distribution, and the dynamic equation of strength degradation is Monte Carlo to simulate the actual use in the situation, the residual strength the phenomenon which degradation along with the time. Again further analyze Weibull Model and Eta Model by fitting. Describes its behavior and discusses reliability degradation and the composite the residual strength distributed change. Then according to the theory that the stress applied of the first stage, derive the dynamic equation of strength degradation at second stage, consider regarding as the stress adjustment the exchange point with the reliability and doing Monte Carlo to simulate, can find the exchange points of two stages will be different to some extent because it is different to applied the order in the stress. Transformed the low stress by the high stress, appear section of approximate free failure time period the phenomenon, And this section increases greatly because of the height stress’s disparity, derive out this section according to this phenomenon, and compare their accuracy in order to simulated results. If further come to do the discussion, only discuss the range of 1>R>0.99, can regard this period as warranty period.
