【摘要】：K-cor結(jié)構(gòu)是應(yīng)用Z-pin技術(shù)增強(qiáng)的一種新型高性能夾層結(jié)構(gòu),更好的滿足了航空航天輕質(zhì)高強(qiáng)的需求。目前國內(nèi)外對K-cor結(jié)構(gòu)在工程應(yīng)用過程中濕熱環(huán)境影響研究報(bào)道較少。本文針對K-cor結(jié)構(gòu)在濕熱、低速?zèng)_擊以及濕熱下低速?zèng)_擊的力學(xué)性能變化,研究Z-pin的增強(qiáng)機(jī)制、結(jié)構(gòu)的損傷機(jī)理以及失效模式,以便設(shè)計(jì)綜合性能優(yōu)異的K-cor夾層結(jié)構(gòu)。研究了Z-pin植入與面板鋪層角度對K-cor結(jié)構(gòu)吸濕性的影響,結(jié)果表明:Z-pin的植入并不會(huì)影響K-cor結(jié)構(gòu)的吸濕性,反而會(huì)提高結(jié)構(gòu)的界面結(jié)合強(qiáng)度,增加尺寸穩(wěn)定性;在水汽濃度較大的情況下,面板鋪層角度變化越小,結(jié)構(gòu)的吸濕增重率越低。采用三點(diǎn)彎曲和壓縮性能試驗(yàn)來研究濕熱后K-cor結(jié)構(gòu)芯材力學(xué)性能的變化,結(jié)果表明:Z-pin植入密度的增加能明顯提高濕熱前后試樣三點(diǎn)彎曲強(qiáng)度和壓縮強(qiáng)度,且具有較高的強(qiáng)度保持率,Z-pin密度為12mm×12mm的K-cor夾層結(jié)構(gòu)濕熱處理試樣的三點(diǎn)彎曲強(qiáng)度比未濕熱處理空白試樣的要高11.1%,8mm×8mm K-cor濕熱處理試樣的芯部壓縮強(qiáng)度比未濕熱處理空白夾層結(jié)構(gòu)試樣要高17.5%,體現(xiàn)出K-cor夾層結(jié)構(gòu)優(yōu)異的抗?jié)駸嵝阅?Z-pin植入角度的減小能明顯提高試樣濕熱處理前后的壓縮強(qiáng)度,0°植入的K-cor試樣濕熱處理后芯部的壓縮強(qiáng)度基本上與40°植入的K-cor試樣未濕熱處理基本相同,但植入角度對三點(diǎn)彎曲強(qiáng)度影響較小。利用落錘沖擊開展K-cor夾層結(jié)構(gòu)的低速?zèng)_擊試驗(yàn),并結(jié)合紅外無損檢測和剩余壓縮強(qiáng)度(CAI)試驗(yàn),研究K-cor結(jié)構(gòu)的抗沖擊性能。結(jié)果表明:K-cor夾層結(jié)構(gòu)的芯材越厚,則其沖擊損傷面積越大,但剩余強(qiáng)度保持率越高;Z-pin折彎長度在不超過植入間距的前提下增長,能顯著的降低K-cor結(jié)構(gòu)沖擊后的損傷面積,提高剩余壓縮強(qiáng)度;在相同芯材密度的情況下,提高Z-pin的折彎長度比增大植入密度更有利于減少K-cor試樣沖擊后的損傷面積,提高試樣的剩余壓縮強(qiáng)度和其強(qiáng)度保持率。另外沖頭參數(shù)為10mm/1.28Kg的落錘比沖頭參數(shù)為12.5mm/2Kg的落錘對K-cor結(jié)構(gòu)造成的沖擊損傷更為嚴(yán)重。綜合考慮濕熱環(huán)境以及低速?zèng)_擊對K-cor結(jié)構(gòu)性能的影響,設(shè)計(jì)濕熱處理后K-cor結(jié)構(gòu)的落錘沖擊,并進(jìn)行測量損傷面積、損傷深度以及CAI的試驗(yàn),研究結(jié)果表明:Z-pin植入密度的增加有效降低了濕熱環(huán)境對K-cor夾層結(jié)構(gòu)的沖擊損傷面積和損傷深度的負(fù)面影響,緩解了試樣在側(cè)壓模式下失效機(jī)制的改變所引起的剩余強(qiáng)度大幅度下降,使K-cor結(jié)構(gòu)抗沖擊性能更穩(wěn)定。
[Abstract]:K-cor structure is a new type of high performance sandwich structure strengthened by Z-pin technology, which better satisfies the requirements of aerospace lightweight and high strength. At present, there are few reports at home and abroad on the influence of wet-heat environment of K-cor structure in engineering application. In this paper, the mechanical properties of K-cor structure under wet-heat, low-speed impact and low-speed impact are studied, and the strengthening mechanism, damage mechanism and failure mode of Z-pin structure are studied. In order to design K-cor sandwich structure with excellent comprehensive performance. The effect of Z-pin implantation and overlay angle on the hygroscopicity of K-cor structure was studied. The results showed that Z-pin implantation did not affect the hygroscopicity of K-cor structure, but increased the interfacial bonding strength and dimensional stability of the structure. In the case of large water vapor concentration, the smaller the change of the laminate angle is, the lower the moisture absorption and weight gain rate of the structure is. Three-point bending and compression tests were used to study the changes of mechanical properties of K-cor core after hot and humid conditions. The results showed that the increase of Z-pin implant density could significantly increase the three-point bending strength and compressive strength of samples before and after wet-heat treatment. The three-point bending strength of the K-cor sandwich structure with Z-pin density of 12mm 脳 12mm is 11.1% higher than that of the blank sample without wet heat treatment. The compressive strength of 8mm 脳 8mm K-cor wet-heat treated specimen is 17.5% higher than that of non-wet-heat treated blank sandwich structure, which shows the excellent hygrothermal resistance of K-cor sandwich structure. The reduction of Z-pin implantation angle can obviously improve the compressive strength of the samples before and after wet-heat treatment. The compressive strength of the core of the K-cor samples implanted in 0 擄after wet-heat treatment is basically the same as that of the K-cor samples implanted in 40 擄without wet-heat treatment. However, the implantation angle has little effect on the three-point bending strength. The low-speed impact test of K-cor sandwich structure was carried out by means of drop hammer impact, and the impact resistance of K-cor structure was studied by means of infrared nondestructive test and residual compressive strength (CAI) test. The results show that the thicker the core of K-cor sandwich structure is, the larger the impact damage area is, but the higher the retention rate of residual strength is. With the increase of bending length of Z-pin, the damage area of K-cor structure after impact can be significantly reduced and the residual compressive strength can be improved by increasing the bending length without exceeding the distance between implants. Under the condition of the same core density, increasing the bending length of Z-pin is more beneficial to reduce the damage area of K-cor specimen after impact than to increase the implant density, and improve the residual compressive strength and the strength retention rate of the sample. In addition, the impact damage of the K-cor structure caused by the drop hammer with the punch parameter of 10mm/1.28Kg is more serious than that of the drop hammer with the punch parameter of 12.5mm/2Kg. Considering the influence of wet-heat environment and low-speed impact on the performance of K-cor structure, the falling hammer impact of K-cor structure after wet-heat treatment is designed, and the damage area, damage depth and CAI are measured. The results show that the increase of Z-pin implant density effectively reduces the negative effect of wet-heat environment on the impact damage area and damage depth of K-cor sandwich structures. The residual strength caused by the change of failure mechanism under lateral pressure mode is alleviated and the impact resistance of K-cor structure is more stable.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：TB383.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 黨詡昂;;解析復(fù)合材料夾層結(jié)構(gòu)在航空領(lǐng)域的運(yùn)用[J];科技與企業(yè);2015年09期

2 萬玉敏;張發(fā);竺鋁濤;;泡沫夾層復(fù)合材料與復(fù)合材料層合板低速?zèng)_擊性能的比較[J];機(jī)械工程材料;2014年07期

3 陳龍輝;付杰斌;王強(qiáng);李偉東;陳里根;;復(fù)合材料夾層結(jié)構(gòu)在航空領(lǐng)域的應(yīng)用[J];教練機(jī);2014年02期

4 謝宗蕻;劉海涵;田江;;復(fù)合材料泡沫夾層板準(zhǔn)靜態(tài)壓痕實(shí)驗(yàn)的有限元模擬[J];材料工程;2014年02期

5 Zheng Yingying;Xiao Jun;Duan Mufeng;Li Yong;;Experimental study of partially-cured Z-pins reinforced foam core composites:K-Cor sandwich structures[J];Chinese Journal of Aeronautics;2014年01期

6 段沐楓;肖軍;李勇;沈裕峰;;K-cor夾層結(jié)構(gòu)的平壓性能[J];復(fù)合材料學(xué)報(bào);2014年05期

7 劉樹亮;馬玉璞;郭萬濤;張興剛;;Z向增強(qiáng)泡沫夾芯結(jié)構(gòu)的制備技術(shù)研究[J];材料開發(fā)與應(yīng)用;2012年01期

8 吳揚(yáng);董浩;段躍新;肇研;;濕熱循環(huán)對PMI泡沫/3218-1環(huán)氧樹脂夾層結(jié)構(gòu)性能影響的研究[J];玻璃鋼/復(fù)合材料;2012年01期

9 劉永濤;楊杰;黃業(yè)青;劉新東;謝瑞廣;王兆華;;泡沫夾層復(fù)合材料耐水性能研究進(jìn)展[J];材料導(dǎo)報(bào);2011年S2期

10 趙銳霞;尹亮;潘玲英;;PM I泡沫夾層結(jié)構(gòu)在航天航空工業(yè)的應(yīng)用[J];宇航材料工藝;2011年02期

，

本文編號(hào)：2436182