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主要研究带切口和无切口,折角[0/±30/±60/90]的玻纤增强环氧组合结构在静力和疲劳荷载下的弯曲性能。确定了带切口和无切口折角试件的静态和疲劳性能。为此,在试件中心钻了2,4.5,7,9mm的不同圆形切口。在零度低应力和25Hz下,进行了常规挠度弯曲疲劳试验,构建了玻纤增强环氧组合试件全截面与净截面的S-N图表。结果显示,带切口玻纤增强环氧组合试件最终挠度随着切口直径的增加而线性减小。对于全截面,随着切口尺寸减小,疲劳寿命增加;而无切口的试件具有较长疲劳寿命。另一方面,基于净截面的S-N图表显示折角组合结构对于切口尺寸的敏感性。对于复合材料这被认为是特殊的情况。结果也显示,在严格的107次循环之内,S-N图表没有任何的疲劳极限。
Mainly studied the bending performance of glass fiber reinforced epoxy composite structures with and without incisions and angle [0 / ± 30 / ± 60/90] under static and fatigue loads. The static and fatigue properties of specimens with and without nicked corner were determined. To this end, the center of the specimen drilled 2,4,5,7,9 mm different circular incision. Under zero low stress and 25Hz, the conventional deflection bending fatigue test was carried out, and the S-N chart of the full cross section and the net cross section of the glass fiber reinforced epoxy composite test piece was constructed. The results show that the ultimate deflection of the notch-cut glass fiber reinforced epoxy composite decreases linearly with the increase of the cut-out diameter. For the full cross-section, the fatigue life increases as the incision size decreases; whereas the non-notched specimen has a longer fatigue life. On the other hand, the S-N chart based on the net section shows the sensitivity of the corner box structure to the size of the slit. This is considered a special case for composite materials. The results also showed that within the strict 107 cycles, the S-N chart did not have any fatigue limit.