Z-pin增强帽型加筋壁板连接机理与力学性能研究

发布时间：2018-01-02 14:29

本文关键词：Z-pin增强帽型加筋壁板连接机理与力学性能研究　出处：《南京航空航天大学》2016年硕士论文　论文类型：学位论文

【摘要】：本文以某新型高教机帽型加筋壁板Z-pin三维增强为应用背景,开展了Z-pin增强帽型加筋壁板结构的成型工艺、增强机理和力学性能研究。提出了Z-pin增强帽型加筋壁板结构的成型工艺方案,成功制备出Z-pin增强帽型加筋壁板试样,并对其进行了拉伸性能、弯曲性能及冲击性能测试分析,探究了Z-pin对帽型加筋壁板筋条与蒙皮界面连接的增强机理,获得了不同参数对其性能的影响规律,为Z-pin增强在航空航天领域加筋壁板上的实际应用奠定了基础。(1)采用金属-硅橡胶软模制备Z-pin增强帽型加筋壁板工艺方案,建立了硅橡胶膨胀压力模型,分析得出最佳工艺间隙为0.4mm,并根据此参数设计了相应的金属阴模及橡胶芯模;通过单pin拔出桥率和凸台剪切试验,研究了Z-pin与基体结合性能及Z-pin的剪切性能;通过对Z-pin植入工艺进行改进,提出了一种精确控制Z-pin植入角度、植入深度的Z-pin植入工艺方法;探索出适于Z-pin增强帽型加筋壁板的热膨胀-热压机混合固化工艺,成功制备出高质量的Z-pin增强帽型加筋壁板试样。(2)开展了Z-pin增强帽型加筋壁板接头的面外拉伸性能研究。研究结果表明:Z-pin对帽型加筋壁板筋条与蒙皮界面拉脱强度有显著增强作用;随着Z-pin体积分数的增加,Z-pin增强试样的拉脱强度呈先升高后降低趋势,相比于不含Z-pin增强试样最高可提高31.15%;Z-pin植入直径的变化对帽型接头拉脱强度的影响不显著;随着加载跨距的增加,Z-pin增强帽型接头的拉脱强度呈降低趋势,Z-pin的主要失效模式由拔脱失效转为剪切失效;除缺陷位于R角内部外,含预制缺陷的Z-pin增强帽型接头试样的拉脱强度均高于不含Z-pin增强试样。(3)开展了Z-pin增强帽型加筋壁板试样的弯曲性能研究。研究结果表明:随着Z-pin体积分数的增加,Z-pin增强帽型加筋壁板的弯曲性能提高,经理论分析得到当Z-pin体积分数为2.6%时,试样弯曲性能最好;Z-pin植入直径的变化对帽型加筋壁板的弯曲峰值力影响不明显;当Z-pin增强区长度为总长度的48%时,Z-pin增强帽型加筋壁板的弯曲峰值力与全部植入Z-pin时基本相当。(4)开展了Z-pin增强帽型加筋壁板冲击性能研究,结合超声C扫描检测方法及冲击后拉伸试验研究了Z-pin对帽型加筋壁板低速冲击的增强机理。结果表明,Z-pin能明显提高帽型加筋壁板的抗冲击性能及剩余拉脱强度;随着Z-pin体积分数的增加,冲击后试样的分层面积减小、剩余拉脱强度增加,当体积分数为1.0%时,10J冲击能量对试样的拉脱强度几乎没有影响;增加Z-pin的直径,冲击后试样的分层面积增加,剩余拉脱强度减小;随着冲击能量的增加,冲击后试样的分层面积增加,剩余拉脱强度减小,冲击能量为18J试样的损伤面积达到筋条与蒙皮连接总面积的82.0%,剩余拉脱强度降低为未冲击试样的25.1%;当冲击帽型筋条中心部位时,10J冲击能量对试样拉伸性能几乎没有影响。
[Abstract]:This paper takes a new type of higher education hat stiffened panel of three dimensional contrast enhanced Z-pin as the application background, the forming process of Z-pin reinforced hat stiffened panel structure, reinforced mechanism and mechanical properties. The enhanced Z-pin scheme forming hat stiffened panel structure, successfully prepared Z-pin enhanced cap type wainscot samples, and has carried on the analysis of tensile properties, flexural strength and impact performance test, to explore the Z-pin on hat stiffened panel ribs and skin interface enhancement mechanism, the influence of different parameters on its performance, which laid the foundation for the enhancement of Z-pin application in the field of aerospace reinforcement on the wall. (1) preparation of Z-pin reinforced panel process hat stiffened by metal - silicon rubber soft molding, set up the pressure model of silicon rubber expansion, analysis of the optimum clearance for the 0.4mm, and according to the design parameters The metal mold and the corresponding rubber core mould; through the single pin pull out the bridge boss rate and shear test, the shear behavior of Z-pin combined with the matrix properties and Z-pin; the Z-pin implantation process improvement, this paper proposes a precise control of Z-pin angle, Z-pin implantation process of insertion depth exploration; for enhanced Z-pin hat stiffened panel thermal expansion - mixed hot press curing process, successfully prepared high quality Z-pin reinforced hat stiffened panel specimens. (2) carried out a study to enhance the performance of Z-pin hat stiffened panel joint surface tension. The results show that Z-pin significantly enhanced the pull strength hat stiffened panel ribs and skin interface; with the increase of the volume fraction of Z-pin Z-pin enhanced tensile strength of samples increased at first and then decreased, compared to the sample without Z-pin enhanced 31.15% higher Z-pin implantation; The influence of the diameter change of cap type joint tensile strength is not significant; with the increase of the loading span, Z-pin enhanced tensile strength cap type joints decreased, the main failure modes of Z-pin by pulling out failure to shear failure; in addition to defects in R internal angle, tensile strength of welded joint with a prefabricated cap type missing in the enhanced Z-pin were higher than those without Z-pin were increased. (3) carried out research on the bending performance of Z-pin reinforced hat stiffened panel specimens. The results show that with the increase of the volume fraction of Z-pin Z-pin to enhance the bending of a hat stiffened panel can be improved by theoretical analysis, when the volume fraction of Z-pin was 2.6% when the bending properties of samples is best; effects of Z-pin on implant diameter hat stiffened panel bending force peak is not obvious; when Z-pin enhanced zone length is the total length of 48%, Z-pin enhanced hat stiffened panel bending peak force With all the Z-pin implantation is quite basic. (4) carried out a study on impact strength of reinforced Z-pin hat stiffened panel, after tensile test studied the enhancement mechanism of Z-pin on hat stiffened panel with low velocity impact of ultrasonic C scanning detection method and impact. The results show that Z-pin can significantly improve the impact properties and residual tensile strength hat stiffened panel; with the increase of the volume fraction of Z-pin samples after impact delamination area decreases, increase the residual tensile strength, when the volume fraction of 1%, almost no influence on the tensile strength of 10J sample energy impact; increased Z-pin diameter, impact delamination area of the specimen increases, reduce the residual tensile strength; with the increase of the impact energy, impact delamination area of the specimen increases, reduce the residual tensile strength, the impact energy for the damage area of 18J specimen reached the ribs and skin with 82% of the total area, the remaining Pull off strength has been reduced to 25.1% when the position of impact test specimens; the impact of cap type rib center, 10J impact energy on tensile performance and almost no effect.

【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V214;V262

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