泡沫夹芯复合材料T型接头弯曲性能研究

发布时间：2018-03-12 13:25

本文选题：T型接头　切入点：夹芯结构　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：T型接头是船舶中的重要连接结构之一,常用于连接隔水舱舱壁和船体。T型接头既能有效分散载荷,也可保持船体的整体耐水性。当船体承受外界载荷时,通过T型连接可以实现垂直面间载荷的传递。因此T型连接的接头处是整个结构中最为关键的环节。船舶的安全性在很大程度上取决于子结构之间的T型接头。因此设计合理的复合材料夹芯结构T型接头对船舶安全意义重大。相较于传统的金属或纯复合材料T型接头,泡沫夹芯复合材料T型接头具有质量轻、刚度高以及抗冲击性能好的优点。采用泡沫夹芯T型接头替代传统T型接头必将成为船舶建造中的主流趋势。因此本文结合有限元分析法,研究了泡沫夹芯复合材料T型接头的几何形状对其抗静态弯曲载荷以及瞬态弯曲载荷的影响。材料性能参数的准确性决定了分析结果的正确与否。为此本文首先通过一系列实验测定了接头所用方格布增强复合材料的基本力学性能。通过ANSYS的APDL语言建立了T型接头的参数化有限元模型,并参考álvaro失效准则以及Ye分层失效准则,根据纤维织物复合材料的特点给出了本文的失效判据以及刚度退化方式。采用APDL语言编写了T型接头的渐进失效分析程序,并通过拉伸实验验证了程序的有效性。采用正交实验法,考察了泡沫夹芯厚度、三角泡沫垫角度、加强片厚度以及横板上加强片长度四个因素对泡沫夹芯复合材料T型接头的抗弯曲性能的影响。结果表明对接头弯曲性能的影响程度从强到弱依次为:芯材厚度、泡沫垫角度、横板上加强片末端距离横板末端的距离以及加强片厚度。最优的T型接头方案:泡沫厚度为50mm、泡沫垫的角度为60°、加强片厚度为7mm以及上加强片末端距离横板末端20mm。该方案并未出现在已做过的9组实验中,通过补充模拟验证实验证明了最佳方案确实具有最高的抗弯曲性能。最后采用瞬态分析研究了四个因素分别对接头抗瞬态弯曲载荷的影响。结果表明当泡沫垫的角度增加时,接头的抗动态载荷性能出现波动,70°是泡沫垫的最佳设计角度;与前者类似,当芯材厚度的增加时,接头的抗动态载荷性能也出现波动,40mm是最佳设计厚度;加强片厚度的增加会降低瞬态弯曲载荷性能,3mm是最佳设计厚度;加强片末端距离的增加会导致接头的抗瞬态弯曲载荷性能呈现先降低后增长,60mm是最佳的设计长度。
[Abstract]:T joint is one of the important connection structures in ship. It is often used to connect the tank bulkhead with the hull. T joint can not only effectively disperse the load, but also maintain the overall water resistance of the hull. The load transfer between vertical planes can be realized by T-joint, so the joint of T-joint is the most important link in the whole structure. The safety of ship depends to a great extent on the T-joint between substructures. Therefore, it is of great significance to design a reasonable T-joint of composite sandwich structure for ship safety. Compared with traditional metal or pure composite T-joints, Foam sandwich composite T-joint has light weight, The advantages of high stiffness and good impact resistance. Replacing the traditional T-joints with foam sandwich T-joints will become the mainstream trend in ship construction. The effect of geometry of foam sandwich composite T-joint on static bending load and transient bending load is studied. The accuracy of material performance parameters determines whether the analysis results are correct or not. Through a series of experiments, the basic mechanical properties of the square cloth reinforced composites used in the joints were measured. The parameterized finite element model of T-joints was established by ANSYS's APDL language. According to the characteristics of fiber fabric composites, the failure criterion and stiffness degradation mode of this paper are given according to the failure criterion of 谩 lvaro and Ye delamination failure criterion. The progressive failure analysis program of T-joint is compiled by APDL language. The validity of the program was verified by tensile test. The thickness of foam sandwich and the angle of triangular foam pad were investigated by orthogonal experiment. The influence of four factors on the bending resistance of foam sandwich composite T-joints is shown as follows: the thickness of core material and the angle of foam pad, the order of the influence on the bending properties of the joints is: the thickness of core material and the angle of foam pad. The distance between the end of the stiffener and the end of the transverse plate and the thickness of the stiffener. The optimum T-joint scheme is: foam thickness is 50mm, foam pad angle is 60 掳, stiffener thickness is 7mm and the upper stiffener ends are close to the end of the transverse plate. 20mm. the scheme did not appear in the nine groups of experiments that have been done, The experimental results of supplementary simulation verify that the best scheme has the highest bending resistance. Finally, the effects of four factors on the bending load of the joint are studied by transient analysis. The results show that when the angle of foam pad is increased, The optimum design angle of foam pad is that the dynamic load resistance of the joint fluctuates 70 掳, and the optimum design thickness is 40mm when the thickness of core material increases. The optimum design thickness is 3 mm when the thickness of the stiffener increases, and the optimum design length is 60 mm after the increase of the end distance of the stiffener.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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