【摘要】：復(fù)合材料由于其優(yōu)異的力學(xué)性能,逐步在航空工業(yè)中用做承力件。在復(fù)合材料的使用過(guò)程中產(chǎn)生過(guò)大的應(yīng)力往往會(huì)使其失效,頻繁的更換部件又會(huì)影響成本。因此,對(duì)復(fù)合材料在役構(gòu)件的應(yīng)力變化值進(jìn)行實(shí)時(shí)檢測(cè)對(duì)航空工業(yè)有著重要的意義。由于使用X射線應(yīng)力檢測(cè)儀無(wú)法直接得到復(fù)合材料的殘余應(yīng)力。采用在復(fù)合材料表面粘貼一層介質(zhì),通過(guò)檢測(cè)介質(zhì)的殘余應(yīng)力和加載后介質(zhì)應(yīng)力的大小,得到加載過(guò)程中介質(zhì)的應(yīng)力變化值。根據(jù)推導(dǎo)得到的介質(zhì)與復(fù)合材料應(yīng)力變化值關(guān)系計(jì)算得出復(fù)合材料表面的應(yīng)力變化值。分別選擇直徑為0.03mm的不銹鋼絲薄膜和厚度為0.025mm的鋁箔作為介質(zhì),檢測(cè)其殘余應(yīng)力。結(jié)果表明,在不銹鋼絲間距為0.5mm處,得到不銹鋼絲的主應(yīng)力為-69.64±13.63MPa。并先后兩次驗(yàn)證確定不銹鋼絲殘余應(yīng)力的穩(wěn)定性。然而,當(dāng)不銹鋼絲與樹(shù)脂膠復(fù)合后,其殘余應(yīng)力數(shù)值分布由-240.4MPa~249.3MPa。結(jié)果差異較大的原因是由于不銹鋼絲直徑過(guò)細(xì),樹(shù)脂膠在固化過(guò)程中對(duì)不銹鋼絲的力學(xué)性能影響極大,影響不銹鋼絲應(yīng)力結(jié)果的穩(wěn)定性。用X射線應(yīng)力檢測(cè)儀對(duì)鋁箔進(jìn)行殘余應(yīng)力檢測(cè)時(shí),發(fā)現(xiàn)在保證鋁箔表面平整的同時(shí),對(duì)其采用適當(dāng)?shù)耐嘶鸸に?可以得到鋁箔穩(wěn)定的殘余應(yīng)力值。在10-1Pa的真空條件下,使鋁箔在一個(gè)半小時(shí)內(nèi)升溫至250℃,保溫十個(gè)小時(shí)之后,再使鋁箔隨退火爐進(jìn)行冷卻。對(duì)其進(jìn)行應(yīng)力檢測(cè),得到鋁箔的主應(yīng)力為-42.93MPa~-7.57MPa,結(jié)果穩(wěn)定。分別對(duì)復(fù)合材料底部施加300N、600N、900N、1200N和1500N的載荷,檢測(cè)鋁箔-樹(shù)脂基復(fù)合材料表面的應(yīng)力值,根據(jù)推導(dǎo)得出的復(fù)合材料與鋁箔應(yīng)力變化值的數(shù)值關(guān)系,計(jì)算得到復(fù)合材料表面在不同載荷下的應(yīng)力變化值。使用ANSYS軟件對(duì)表面粘貼有鋁箔的復(fù)合材料加載過(guò)程進(jìn)行數(shù)值模擬,將鋁箔部分?jǐn)?shù)值模擬結(jié)果與實(shí)驗(yàn)中鋁箔的第10點(diǎn)應(yīng)力變化值進(jìn)行比較,發(fā)現(xiàn)其大體相符。當(dāng)復(fù)合材料受到載荷越大時(shí),實(shí)驗(yàn)與模擬所得到的應(yīng)力檢測(cè)結(jié)果相差越小。復(fù)合材料加載過(guò)程中實(shí)驗(yàn)影響因素過(guò)多,會(huì)有異常點(diǎn)的出現(xiàn)。對(duì)復(fù)合材料加載過(guò)程中,其應(yīng)力值的變化進(jìn)行模擬,有助于排除應(yīng)力檢測(cè)過(guò)程中出現(xiàn)的異常點(diǎn)。
[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 鹵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，

本文編號(hào)：2444519