摘要
碳纤维增强树脂基复合材料(carbon fiber reinforced polymers,CFRP)在航空领域应用广泛,但极易发生铆接损伤。针对航空CFRP构件,本文通过试验研究带垫圈铆接损伤行为,评估不同宽径比和边径比下铆接构件拉伸剪切性能。结果表明:镦头径向过度膨胀和镦头轴向变形挤压共同造成CFRP孔口局部应力过大,进而引起局部铆接损伤,且镦头附近铺层挤压损伤最明显。垫圈一方面有效限制了镦头附近钉杆不均匀膨胀;另一方面通过将局部轴向挤压力向孔周表面垫圈覆盖区域分散进而降低孔周表面轴向应力水平,最终有效减小了铆接损伤程度。所有试件力-位移响应曲线特征由钛合金铆钉主导,伴随铆钉剪切失效。拉伸失效过程中,垫圈均未发生明显变形,但CFRP层板钉孔周围表层发生明显局部挤压损伤,同时拉伸过程中伴随纤维断裂声响。宽径比对试件刚度和最终失效强度均具有明显影响,但边径比影响不明显。为探究与传统铆接相比更高效的铆接方式,本文针对CFRP/CFRP复合材料铆接构件,创新性地引入了带垫圈的铆接方法,通过铆接、拉伸剪切试验验证和铆接试件微观表征,发现垫圈能够有效抑制镦头的膨胀,并分散孔周应力水平进而降低铆接损伤。铆接试件的宽径比相较于边径比对铆接试件刚度和失效强度的影响更为显著。在拉伸剪切试验中,铆接试件的失效模式均为铆钉断裂。
Carbon fiber reinforced polymer composites(CFRP)are widely used in the field of aerospace but it is prone to suffer from riveting damage.This work experimentally investigated the riveting damage behaviors of the CFRP riveted joints with gaskets and evaluated the tensile shearing properties of joints at different width-diameter ratios and edge displacement-diameter ratios.The results demonstrated that the rivet tail’s excessive expansion in the radial direction and extrusion deformation in the axial direction led to high local stress on the CFRP hole and thus riv-eting damage.The most critical damage occurred on the plies near the riveted head.The gasket can effectively limit the uneven expansion near the rivet tail and can reduce axial stress of the hole surface by dispersing the local axial extrusion force to the gasket coverage area around the hole,which helped reduce riveting damage.The load-displacement response curves of all specimens were dominated by rivets,accompanied by rivet shearing failure.During tensile shearing testing,the gasket was un-deformed but local extrusion damage occurred at the local region near the hole of CFRP along with fiber tensile fracture noise.The width to diameter ratio exhibited an obvious influence on the specimen stiffness and failure strength,while the edge displacement to diameter ratio had little influence on them.In order to explore a more efficient riveting method compared to traditional riveting,this paper focused on CFRP/CFRP composite riveted structures and introduced a novel riveting method with gaskets.Through riveting and tensile-shear tests and microscopic observation of the riveted specimens,it was found that gaskets could reduce riveting damage by suppressing the expansion of the rivet head and dispersing stress around the hole.The width-to-diameter ratio of the riveted specimens had a more significant influence on their stiffness and failure strength compared to the edge-to-diameter ratio.In the tensile-shear tests,all the fail-ure modes of the riveted specimen
作者
杨洲
邓金风
蒋睿嵩
左杨杰
YANG Zhou;DENG Jinfeng;JIANG Ruisong;ZUO Yangjie(School of Aeronautics and Astronautics,Sichuan Univ.,Chengdu 610065,China;School of Mechanical Eng.Sichuan Univ.,Chengdu 610065,China;School of Aeronautics,Northwestern Polytechnical Univ.,Xi’an 710072,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2023年第5期212-220,共9页
Advanced Engineering Sciences
基金
四川省科技计划资助(2020YFG0109)
中国博士后科学基金面上项目(2020M673227)
四川大学专职博士后研发基金(20826041E4152)。
关键词
复合材料
铆接
垫圈
损伤
失效
composite
riveting
gasket
damage
failure
