X射线衍射法检测碳纤维增强树脂基复合材料应力研究
发布时间：2019-03-20 18:56
【摘要】：复合材料由于其优异的力学性能,逐步在航空工业中用做承力件。在复合材料的使用过程中产生过大的应力往往会使其失效,频繁的更换部件又会影响成本。因此,对复合材料在役构件的应力变化值进行实时检测对航空工业有着重要的意义。由于使用X射线应力检测仪无法直接得到复合材料的残余应力。采用在复合材料表面粘贴一层介质,通过检测介质的残余应力和加载后介质应力的大小,得到加载过程中介质的应力变化值。根据推导得到的介质与复合材料应力变化值关系计算得出复合材料表面的应力变化值。分别选择直径为0.03mm的不锈钢丝薄膜和厚度为0.025mm的铝箔作为介质,检测其残余应力。结果表明,在不锈钢丝间距为0.5mm处,得到不锈钢丝的主应力为-69.64±13.63MPa。并先后两次验证确定不锈钢丝残余应力的稳定性。然而,当不锈钢丝与树脂胶复合后,其残余应力数值分布由-240.4MPa~249.3MPa。结果差异较大的原因是由于不锈钢丝直径过细,树脂胶在固化过程中对不锈钢丝的力学性能影响极大,影响不锈钢丝应力结果的稳定性。用X射线应力检测仪对铝箔进行残余应力检测时,发现在保证铝箔表面平整的同时,对其采用适当的退火工艺,可以得到铝箔稳定的残余应力值。在10-1Pa的真空条件下,使铝箔在一个半小时内升温至250℃,保温十个小时之后,再使铝箔随退火炉进行冷却。对其进行应力检测,得到铝箔的主应力为-42.93MPa~-7.57MPa,结果稳定。分别对复合材料底部施加300N、600N、900N、1200N和1500N的载荷,检测铝箔-树脂基复合材料表面的应力值,根据推导得出的复合材料与铝箔应力变化值的数值关系,计算得到复合材料表面在不同载荷下的应力变化值。使用ANSYS软件对表面粘贴有铝箔的复合材料加载过程进行数值模拟,将铝箔部分数值模拟结果与实验中铝箔的第10点应力变化值进行比较,发现其大体相符。当复合材料受到载荷越大时,实验与模拟所得到的应力检测结果相差越小。复合材料加载过程中实验影响因素过多,会有异常点的出现。对复合材料加载过程中,其应力值的变化进行模拟,有助于排除应力检测过程中出现的异常点。
[Abstract]:Because of its excellent mechanical properties, composite materials are gradually used as bearing parts in aviation industry. In the process of using composite materials, too much stress will often make them fail, and frequent replacement of parts will affect the cost. Therefore, it is very important for aviation industry to detect the stress change value of composite material in service in real time. The residual stress of composites can not be obtained directly by using X-ray stress detector. A layer of media was pasted on the surface of the composite material. The residual stress of the medium and the stress of the medium after loading were measured, and the change value of the stress during the loading process was obtained. According to the relationship between the media and the stress change of the composite material, the stress variation value of the composite material surface is calculated. Stainless steel wire film with diameter of 0.03mm and aluminum foil with thickness of 0.025mm were selected as the medium to detect the residual stress. The results show that the main stress of stainless steel wire is-69.64 卤13.63MPa at the distance between stainless steel wire and 0.5mm. The stability of residual stress of stainless steel wire was confirmed twice. However, when stainless steel wire is combined with resin glue, the residual stress value distribution is-240.4 MPA, 249.3 MPA. The reason for the great difference is that the diameter of stainless steel wire is too fine, the resin adhesive has great influence on the mechanical properties of stainless steel wire during curing process, and affects the stability of stress result of stainless steel wire. When the residual stress of aluminum foil is detected by X-ray stress detector, it is found that the stable residual stress value of aluminum foil can be obtained by proper annealing process while ensuring the smooth surface of aluminum foil. Under the vacuum condition of 10-1Pa, the aluminum foil was heated to 250 鈩，
本文编号：2444519
[Abstract]:Because of its excellent mechanical properties, composite materials are gradually used as bearing parts in aviation industry. In the process of using composite materials, too much stress will often make them fail, and frequent replacement of parts will affect the cost. Therefore, it is very important for aviation industry to detect the stress change value of composite material in service in real time. The residual stress of composites can not be obtained directly by using X-ray stress detector. A layer of media was pasted on the surface of the composite material. The residual stress of the medium and the stress of the medium after loading were measured, and the change value of the stress during the loading process was obtained. According to the relationship between the media and the stress change of the composite material, the stress variation value of the composite material surface is calculated. Stainless steel wire film with diameter of 0.03mm and aluminum foil with thickness of 0.025mm were selected as the medium to detect the residual stress. The results show that the main stress of stainless steel wire is-69.64 卤13.63MPa at the distance between stainless steel wire and 0.5mm. The stability of residual stress of stainless steel wire was confirmed twice. However, when stainless steel wire is combined with resin glue, the residual stress value distribution is-240.4 MPA, 249.3 MPA. The reason for the great difference is that the diameter of stainless steel wire is too fine, the resin adhesive has great influence on the mechanical properties of stainless steel wire during curing process, and affects the stability of stress result of stainless steel wire. When the residual stress of aluminum foil is detected by X-ray stress detector, it is found that the stable residual stress value of aluminum foil can be obtained by proper annealing process while ensuring the smooth surface of aluminum foil. Under the vacuum condition of 10-1Pa, the aluminum foil was heated to 250 鈩，
本文编号：2444519
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