基于疲劳强度分布的复合材料疲劳验证载荷放大系数

传统的载荷放大系数(LFE)法是在复合材料静强度和疲劳寿命的Weibull分布基础上推导得出的。为了保证复合材料疲劳试验验证的可靠性和疲劳载荷放大系数的分散性较小,利用疲劳可靠性理论,提出一种基于复合材料疲劳强度和疲劳寿命Weibull分布的载荷系数法——疲劳强度载荷放大系数(FLEF)法。将LEF和FLEF方法应用于疲劳试验数据分析,结果表明:在无批量数据的前提下,采用LEF法获得的疲劳载荷放大系数无法保证复合材料疲劳试验验证的可靠性,FLEF法确定的载荷系数具有更小的分散性,更高的可靠性。可见,与LEF法相比,FLEF法在理论和实践上更适合复合材料疲劳试验载荷放大系数的确定。

Composite Fatigue Verification Load Enhancement Factor based on Fatigue Strength Distribution

The traditional load enhancement factor (LEF) method was derived from the composite static strength and fatigue life Weibull distribution. In order to ensure the reliability of composite fatigue verification test and a smaller dispersion of load enhancement factor, the fatigue reliability theory was used to derived a new load enhancement factor method based on composite fatigue strength and fatigue life Weibull distribution. This new method is called fatigue strength load enhancement factor (FLEF) method. The LEF and FLEF methods were applied to the analysis of fatigue test data. The results show that the LEF could not guarantee the reliability of composite fatigue verification without batch data and the FLEF has smaller dispersion and higher reliability. It is concluded that compared with the LEF method, the FLEF method is more suitable to determine the load enhancement factor in theory and practice.