【作者】 王俊凯；

【导师】 曲焱喆；

【作者基本信息】 哈尔滨工业大学 ， 航天工程（专业学位）， 2020， 硕士

【摘要】 胶接技术是复合材料的重要连接技术,依靠其优良的粘接性能在航空航天领域获得了快速发展。尽管胶接技术展现出多重突出优势,但由于构建胶接结构的层合板物理性能差异较大、胶层界面的损伤行为复杂,人们难以对其极限承载能力、损伤扩展规律和结构可靠性等进行充分研究,胶接结构在工程实践中一般被应用于弱承载结构而无法充分发挥其优良性能。在复合材料胶接结构中,粘接界面的性质对于材料和结构的整体性能、极限承载能力和损伤行为起着重要作用。因此,分析界面损伤起始、演化和破坏过程,对准确评估材料和结构性能及其后续的设计应用至关重要。本文对内聚力模型的本构关系及其参数确定方法作了详细介绍,在此基础上提出了一种新的界面本构参数确定方案。通过建立复合材料胶接结构在理论状态和试验状态的有限元内聚力模型,以试件的理论态有限元仿真为主要手段结合试验态仿真研究了不同构型的CFRP层合板胶接结构在不同加载方式下的极限承载能力、界面损伤模式和损伤扩展规律,验证了本文提出的本构参数确定方案的准确性与可行性,探究了胶层参数对界面强度的影响规律。结果表明:在不考虑界面损伤的情况下胶接结构表现出比镙接结构更强的承载力,性能优势显著;本文提出一种以实验与有限元仿真结合推测内聚力模型的断裂参数的完整方案并以此方案获得了胶接结构界面的本构模型,经过内聚力模型的理论态与试验态仿真结果对比证明该方案具有可行性;基于内聚力模型的理论态数值模拟结果与试验态数值模拟结果具有一定差异,工程实践中通过仿真模拟获取精确试验结果时对胶接结构进行试验态仿真分析具有必要性;加载方式和粘接界面两侧复合材料的物理性能共同决定了胶接结构的损伤扩展规律,加载方式在粘接界面损伤扩展规律与结构极限承载能力中均起主导作用;复合材料胶接结构的极限承载力与加载方式、粘接长度、胶层厚度、被粘接物的物理性能等因素有关,各因素对极限承载力的影响依次减弱,被粘接物的物理性能对极限承载力的影响程度对加载方式敏感;复合材料胶接结构极限承载能力随胶层厚度、粘接长度的线性变化呈现出具有一定规律的复杂变化。本文工作对研究复合材料胶接结构的极限承载能力和损伤行为具有参考意义,为后续复合材料胶接结构的设计应用提供了有力的理论支撑。更多还原

【Abstract】 Adhesive bonding technology is the main bonding technology of composite materials,which has been developed rapidly in aviation,aerospace and other fields.Although the bonding technology has many advantages,but because the bonding structure has a variety of fibers,different laying methods and adhesive layers,the mechanical behavior is complex,people’s research on its bearing capacity,damage mode and reliability is not in-depth.It has been applied to the weak bearing structure,and its excellent performance has not been fully developed.For composite bonded structures,the properties of bonding interface play an important role in the overall performance,ultimate bearing capacity and damage characteristics of materials and structures.Therefore,the analysis of interface damage initiation,evolution and failure process is very important for the accurate evaluation of material and structure performance and subsequent design applications.In this paper,the constitutive relation of cohesion model and its parameter determination method are introduced in detail.On this basis,a new interface constitutive parameter determination scheme is proposed.Through the establishment of composite material bonding structure in theory and experiment with state of the finite element model of cohesion,to specimen of theory of state as the main method combining finite element simulation test state simulation to study the different configurations of CFRP laminated plate bonding structure under different loading ways of the ultimate bearing capacity,interface damage pattern and damage extension rule,the correctness and feasibility of the scheme for determining constitutive parameters are verified,and the influence of each parameter on the interface strength is discussed.The results show that the adhesive structure has stronger bearing capacity and better performance advantage than the screw structure without considering the interface damage;In this paper,a complete scheme is proposed to predict the fracture parameters of the cohesive force model by combining the experiment with the finite element simulation,and the constitutive model of the bonding structure interface is obtained by this scheme.The feasibility of this scheme is proved by the comparison of the theoretical and experimental simulation results of the cohesive force model;There are some differences between the theoretical and experimental numerical simulation results based on cohesion model,so it is necessary to carry out the experimental simulation analysis for the bonded structure when the accurate test results must be obtained through simulation in engineering practice;The loadingmode and the physical properties of the composites on both sides of the bonding interface jointly determine the damage expansion law of the bonding structure;The loading mode plays a leading role in the damage expansion law of the bonding interface and the ultimate bearing capacity of the structure;The ultimate bearing capacity of composite bonded structure is related to loading mode,bonding length,thickness of adhesive layer,physical properties of the bonded material and other factors;The influence of each factor on the ultimate bearing capacity is weakened in turn,and the degree of influence of the physical properties of the bonded material on the ultimate bearing capacity is sensitive to the loading mode;The ultimate load-carrying capacity of the composite bonded structure varies linearly with the thickness and length of the adhesive layer.The work in this paper has reference significance for the study of the ultimate bearing capacity and damage behavior of composite bonded structures,and provides a strong theoretical support for the design and application of composite bonded structures.更多还原