芯材的表面处理对复合材料夹芯板力学性能的影响

发布时间：2018-05-04 21:30

本文选题：复合材料泡沫夹芯板 + 表面处理　；参考：《武汉理工大学》2015年硕士论文

【摘要】：复合材料泡沫夹芯板不仅具备比强度高、比模量大、抗冲击性能强等良好的力学特点,而且具有隔热、隔音、减振等功能特点,因此,在航空、航天、船舶、能源、交通等领域日益受到关注。为了满足各领域越来越高的工况要求,提高芯材的力学性能成为提高夹芯板整体性能的重要方式之一。将泡沫平板表面处理,即在泡沫表面切割出不同尺寸及分布的切缝,产生的芯材在夹芯板成型后因切缝中的树脂而使力学性能获得提高。目前,经表面处理的芯板应用面越来越广,但芯材表面处理方式对夹芯板力学性能的影响的相关研究还较少见。本文提出表面处理芯材夹芯板的二步结构分析法。第一步,以薄片模型为理论模型,结合ANSYS有限元软件对含树脂的芯材的力学性能进行预测;第二步将芯材看作两层(树脂增强芯材子层1和纯PVC芯材子层2,某些处理方式中可不含有纯芯材层),计算整体夹芯板的力学性能,并通过实验验证,证实了该方法的有效性。为进一步优化设计,考察了切缝深度、宽度、间距及分布对复合材料夹芯板的弯曲、平拉、平压等力学性能的影响。实验中,利用真空灌注VARI(Vacuum Assisted Resin Infusion)成型工艺制备了含不同表面处理方式的芯材的复合材料夹芯板,测定夹芯板试样的弯曲、平拉、平压性能,根据测试结果分析芯材表面处理方式对夹芯板力学性能的影响。主要研究内容和结论如下:(1)以从单向单面切割板ODC(One Directional Coutour)为例,提取芯材子层1的代表性体积单元(单胞),分别用薄片模型理论和ANSYS模拟计算芯材子层1的等效拉伸模量、剪切模量等基本力学参数,结果对比分析表明:通过数值模拟计算单胞的力学性能预测芯材的等效力学性能的方法是合理的;(2)选取芯材多种表面处理方式的代表性尺寸,分别从经表面处理的芯板中提取单胞,利用ANSYS计算芯材的力学性能。结果表明,芯材经过表面处理后,力学性能得到提高;(3)根据国标试验分别模拟计算和测定夹芯板试样的弯曲、平拉、平压性能,模拟结果与实验结果符合较好,说明数值模拟方法是可靠的。所以,首先通过数值预测树脂增强芯材的力学性能,再将含树脂的芯材作为复合材料多层结构中的一层进行整体夹芯板的力学分析的方法是合理可行的;(4)为了优化设计,模拟分析了不同的表面处理方式对夹芯板的力学性能的影响。结果表明,对于本文研究的夹心结构,切缝深度和切缝间距对夹芯板的刚度影响较大,对平拉和平压强度影响较低;切缝宽度可显著提高夹芯板的平拉和平压强度,对夹芯板刚度无影响;组合型表面处理能够提高夹芯板的刚度、平拉和平压强度。
[Abstract]:Composite foam sandwich panels not only have good mechanical characteristics, such as high specific strength, high specific modulus, strong impact resistance and so on, but also have the functions of heat insulation, sound insulation, vibration absorption and so on. Therefore, in aviation, aerospace, ship, energy, etc. Traffic and other fields are getting more and more attention. In order to meet the requirements of higher and higher working conditions in various fields, improving the mechanical properties of core materials has become one of the important ways to improve the overall performance of sandwich panels. The surface of foam plate was treated by cutting out different size and distribution of slits on the foam surface, and the mechanical properties of the core material were improved because of the resin in the cutting joint after the core was formed. At present, the surface treatment of core panels is more and more widely used, but the influence of core surface treatment on the mechanical properties of sandwich panels is rare. In this paper, a two-step structure analysis method for surface treatment core sandwich panel is presented. The first step is to predict the mechanical properties of the core material containing resin by using the thin sheet model as the theoretical model and the ANSYS finite element software. In the second step, the core material is regarded as two layers (resin reinforced core material sub-layer 1 and pure PVC core material sub-layer 2), some treatment methods can not contain pure core material layer, the mechanical properties of the whole sandwich panel are calculated, and the validity of the method is verified by experiments. In order to further optimize the design, the effects of depth, width, spacing and distribution of cutting joint on the mechanical properties of composite sandwich panels, such as bending, flat drawing and flat compression, were investigated. In the experiment, the composite sandwich panels with different surface treatment methods were prepared by vacuum perfusion VARI(Vacuum Assisted Resin Infusion) molding process. The bending, flat drawing and flat compression properties of sandwich plate samples were measured. According to the test results, the effect of core surface treatment on the mechanical properties of sandwich panel is analyzed. The main contents and conclusions are as follows: (1) taking the unidirectional cutting plate ODC(One Directional Coutouras as an example, the representative volume unit of the core sublayer 1 (unit cell model theory and ANSYS simulation is used to calculate the equivalent tensile modulus of the core sublayer 1, respectively. Comparing and analyzing the basic mechanical parameters such as shear modulus, the results show that the method of predicting the equivalent mechanical properties of the core material by numerical simulation is a reasonable one) and the representative size of various surface treatment methods of the core material is selected. The unit cells were extracted from the surface treated core and the mechanical properties of the core were calculated by ANSYS. The results show that after surface treatment, the mechanical properties of the core material are improved. According to the national standard test, the bending, flat drawing and flat compression properties of the sandwich plate samples are calculated and measured respectively. The simulation results are in good agreement with the experimental results. It is shown that the numerical simulation method is reliable. Therefore, it is reasonable and feasible to analyze the mechanical properties of composite sandwich panel by numerical prediction of the mechanical properties of resin reinforced core material, and then to optimize the design by using the resin core material as a layer of composite multilayer structure. The effects of different surface treatments on the mechanical properties of sandwich panels were simulated and analyzed. The results show that, for the sandwich structure studied in this paper, the stiffness of sandwich panel is greatly affected by the depth of cutting joint and the spacing of cutting joint, and the influence on the flat tension and compression strength is low, and the width of cutting joint can significantly improve the flat tension and compression strength of sandwich panel. The composite surface treatment can improve the stiffness of sandwich panel, and the flat tension and compression strength can be improved.
【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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