T字型三维机织物设计及其复合材料力学性能分析

发布时间：2018-06-26 00:51

本文选题：三维机织结构 + T字型三维整体机织复合材料　；参考：《大连工业大学》2015年硕士论文

【摘要】：T型梁作为一种常见的工程结构件,被广泛应用在航空航天航海以及建筑等领域。由于不可定因素的存在,可能会遭遇鸟击、雨雪或冰雹和船只撞击等造成的一些外部损害。作为复合材料增强体的三维机织结构同三维针织结构和三维编织结构相比,具有特殊的结构特点和优异的力学性能,因而设计并制造高弯曲强度和抗冲击性能的T字型三维整体机织复合材料,应用前景十分可观。本课题将玻璃长丝束作为经纱,玄武岩长丝束作为纬纱在普通小样织机上低成本织造成三种不同梁高的T字型三维整体机织物,并采用VARTM(Vacuum Assistant Resin Transfer Moulding)成型工艺制备成复合材料。利用电子万能试验机测试了三种不同梁高的T字型三维整体机织复合材料在准静态下的三点弯曲性能,研究T字型三维整体机织复合材料的破坏模式和能量吸收方式等。从实验所得的载荷-位移曲线和吸收能量-位移曲线关系图来看,随着位移的增加,梁高为12 mm的T字型三维整体机织复合材料所能承载的载荷和吸收的能量最大,梁高为0mm的T字型三维整体机织复合材料最小。从材料最终破坏形态来看,梁高为0 mm的材料表现为典型的弯曲破坏模式,正面受压缩破坏,背面受拉伸破坏,梁高为6 mm和12 mm的材料正面表现为压缩破坏,背面为剪切破坏。可见基体开裂、纤维与树脂脱粘和纤维断裂等破坏是材料弯曲破坏模式中主要的吸收能量方式。在简支梁冲击实验中,T字型三维整体机织复合材料受到的冲击过程几乎是一瞬间发生的,应力传播非常快,材料的结构响应基本失效,应力波受到基体开裂等因素的阻碍,应力无法平衡,容易在摆锤接触材料的位置形成应力集中,造成材料断裂。其中梁高为12mm的材料吸收能量最多,受到的冲击强度最大;梁高为0mm的材料吸收能量最少,受到的冲击强度最小。本课题还基于T字型三维整体机织复合材料试样的尺寸,建立同尺寸结构的模型,运用ABAQUS有限元软件模拟计算同种组织结构下三种不同梁高的T字型三维整体机织复合材料的三点弯曲性能,模拟得到的载荷-位移曲线、吸收能量-位移关系曲线及破坏形态与实验结果相比有较好的一致性。可见,所建模型较正确,为今后T字型三维整体机织复合材料弯曲力学性能模拟,提供一定帮助,可反过来为梁高对试样的影响提供一定指导,减少试验量。
[Abstract]:As a common engineering structure, T-beam is widely used in aerospace navigation and architecture. Due to uncertainties, some external damage may be caused by bird strikes, rain, snow or hail, and ship impacts. Three-dimensional woven structure, as a composite reinforcement, has special structural characteristics and excellent mechanical properties compared with three-dimensional knitted structure and three-dimensional braided structure. Therefore, the design and manufacture of T-shaped 3D monolithic woven composites with high bending strength and impact resistance have a promising application prospect. In this paper, glass filament beam is used as warp yarn and basalt filament beam is used as weft yarn to weave three kinds of T-shaped three-dimensional woven fabrics with different beam height on ordinary sample loom at low cost, and VARTM (Vacuum Assistant Resin transfer Moulding) process is used to fabricate composite material. The three-point bending behavior of three T-shaped 3D monolithic woven composites with different beam heights was tested by electronic universal testing machine, and the failure mode and energy absorption mode of T-shaped 3D monolithic woven composites were studied. From the load-displacement curve and absorption energy-displacement curve diagram obtained from the experiment, with the increase of displacement, the T-shaped 3D monolithic woven composite with a beam height of 12 mm can carry the maximum load and absorb the energy. The T-shaped three-dimensional monolithic woven composite with 0mm beam height is the smallest. According to the ultimate failure pattern of the material, the material with a beam height of 0 mm shows typical bending failure mode, the front of the beam is subjected to compression damage, the back side of the material is damaged by tensile damage, and the front of the material with the beam height of 6 mm and 12 mm shows compression failure. The back side is shear failure. It can be seen that matrix cracking, fiber and resin debonding and fiber fracture are the main energy absorption modes in the bending failure mode of materials. In the impact test of simply supported beam, the impact process of T-shaped 3D monolithic woven composites is almost instantaneous, the stress propagation is very fast, the structural response of the material is basically invalid, and the stress wave is hindered by the cracking of matrix, etc. The stress can not be balanced, and it is easy to form stress concentration in the position of the pendulum hammer contact material, resulting in material fracture. The material whose beam height is 12mm absorbs the most energy and receives the greatest impact strength, while the material with the beam height of 0mm absorbs the least energy and receives the least impact strength. The model of the same size structure is also established based on the size of T-shaped 3D monolithic woven composite material. By using Abaqus finite element software, the three-point bending behavior of three T-shaped 3D monolithic woven composites with different beam heights under the same structure was simulated, and the load-displacement curves were obtained. Compared with the experimental results, the absorption energy displacement curve and the failure pattern are in good agreement. It can be seen that the established model is more correct, which can provide some help for the simulation of bending mechanical properties of T-shaped 3D monolithic woven composites in the future, which can in turn provide some guidance for the influence of beam height on the specimen, and reduce the amount of test.
【学位授予单位】：大连工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TS106;TB33

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