本文採用二元應力階下的受力順序理論模式，用以預測二元應力階疲勞作用下，複合層板殘餘疲勞模數的分佈情形；以此理論模式將可推算以基材主導的複合層板中，在高－低受力順序與低－高受力順序的疲勞作用力下，對其疲勞損傷造成之影響，由理論的預測顯示出低－高受力順序所造成的損傷程度比高－低受力順序較為大。
　另外，以疲勞模數遞減模式為基礎，加上一套合適的破壞準則，用以預測疲勞壽命之分佈，並與SLERA方法做比較，顯示出破壞準則在疲勞壽命預測上較為保守，亦利用文獻實驗結果驗證理論預測的正確性。

　In this research, use theoretical model of load sequence to predict distribution of residual fatigue modulus of composite laminates under dual stress level. The effects on the fatigue damage of matrix dominated laminates under high-low and low-high fatigue loadings could be derived theoretically by employing the proposed model. Theoretical prediction shows that the low-high sequence is more damaging to the matrix dominated composites than the high-low sequence.
　In addition, based on the modified fatigue modulus degradation model, adds on a set of suitable failure criterion, with predict distribution of fatigue life. And compares with method of SLERA, showed that failure criterion is more conservative in prediction of fatigue life. Also comparisons between the predicted distribution of fatigue life and experimental results in references are shown to be reasonable.

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