泡沫铝夹层板仿真建模及压缩性能研究

发布时间：2018-03-15 04:38

本文选题：泡沫铝夹层板　切入点：仿真建模　出处：《昆明理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：泡沫铝材料具有低密度、高比强度和比刚度,不同寻常的声学特性,能量吸收能力高,阻燃性等特性,而广泛应用于汽车工程、船舶和航空航天等领域。但是,此类材料在实际应用中仍面临模量低和表面粗糙等问题而难以单独作为结构材料使用。为解决上述问题,通常将泡沫铝和传统致密金属材料进行复合,其中具有夹芯结构的泡沫铝夹层板是主要复合形式之一。在工程应用中,泡沫铝夹层板与其它金属板材连接存在一定的问题。诸如,泡沫铝夹层板厚且致密化程度低从而导致连接件不能传递大的作用力,甚至引起孔结构的破坏和密封性降低等问题。目前国外已经制备出了面板与泡沫铝芯之间具有冶金结合的泡沫铝夹层板,但是国内泡沫铝夹层板是通过粘接的方法间接获得的,该材料耐高温与耐腐蚀能力较差。鉴于上述原因,本文的工作内容如下：首先,本文综述了泡沫铝夹层板材料的制备方法与技术,给出了每一种制备方法的工艺流程图和得到泡沫铝夹层板的结构形状图。最后总结了泡沫铝夹层板每一种制备方法的优点和缺点。其次,本文在前人的基础上提出了泡沫铝夹层板的建模方法,即泡沫铝夹层板仿真模型生成系统,该系统是模型尺寸、孔隙率、孔径范围以及最小壁厚均为可调的泡沫铝夹层板建模系统,和前人的三维模型相比,更符合真实的泡沫铝夹层板材料结构。但是该模型的内部结构是相当复杂的,在后续计算机仿真软件中网格划分比较难。最后,本文简化了泡沫铝夹层板的仿真模型,采用宏观整体建模方法,采用圆孔假设、均匀化假设等建立泡沫铝夹层板仿真模型。在模拟过程中,利用有限元软件ANSYS/LS-DYNA,通过理论分析和有限元模拟,研究泡沫铝夹层板压缩性能力学行为,以及泡沫铝夹层板在压缩载荷下的变形机理。结果表明,泡沫铝夹层板在压缩载荷的应力-应变曲线中具有弹性区、屈服区和致密区。压缩速度和孔隙率对泡沫铝夹层板材料的压缩力学行为影响显著,随着压缩速度的不断增加,泡沫铝夹层板的抵抗破坏能力提高；随着孔隙率的增大,泡沫铝夹层板的弹性模量和屈服强度逐渐减小。这进一步证实了基体金属的力学性质直接决定了泡沫铝夹层板材料的压缩变形行为,并且泡沫铝夹层板材料的弹性模量、屈服强度等均与基体金属材料的相应性能有关。
[Abstract]:Aluminum foams have the characteristics of low density, high specific strength and specific stiffness, unusual acoustics, high energy absorption, flame retardancy and so on. They are widely used in automotive engineering, ship, aerospace and other fields. In practical application, such materials are still faced with problems such as low modulus and rough surface, which make them difficult to be used as structural materials alone. In order to solve the above problems, aluminum foam and traditional dense metal materials are usually combined. The foam aluminum sandwich plate with sandwich structure is one of the main composite forms. In the engineering application, there are some problems in the connection between the foam aluminum sandwich plate and other metal plates, such as, The thick and low densification of the aluminum foam sandwich plate results in the joint not being able to transmit large forces, At present, a metallurgical aluminum sandwich plate with metallurgical bonding between the panel and the foam aluminum core has been prepared, but the domestic foam aluminum sandwich plate is obtained indirectly by the method of bonding. In view of the above reasons, the work of this paper is as follows: firstly, the preparation method and technology of foam aluminum sandwich plate are reviewed. The process flow chart of each preparation method and the structure shape diagram of the foam aluminum sandwich plate are given. Finally, the advantages and disadvantages of each preparation method are summarized. Secondly, In this paper, the modeling method of foamed aluminum sandwich plate is put forward, that is, the simulation model generation system of foam aluminum sandwich plate. The system is model size, porosity, porosity. The modeling system of aluminum foam sandwich plate with adjustable aperture range and minimum wall thickness is more consistent with the real material structure of the foam aluminum sandwich plate than the previous 3D model, but the internal structure of the model is quite complex. In the following computer simulation software, it is difficult to divide the mesh. Finally, the simulation model of aluminum foam sandwich plate is simplified in this paper, the macro integral modeling method is adopted, and the circular hole hypothesis is adopted. The simulation model of aluminum foam sandwich plate was established by homogenization hypothesis. In the process of simulation, the mechanical behavior of the compressive properties of aluminum foam sandwich plate was studied by theoretical analysis and finite element simulation using the finite element software ANSYS / LS-DYNA. And the deformation mechanism of aluminum foam sandwich plate under compression load. The results show that there is an elastic zone in the stress-strain curve of aluminum foam sandwich plate under compression load. The compressive rate and porosity have a significant effect on the compressive mechanical behavior of the foam aluminum sandwich plate. With the increasing of the compression speed, the resistance to failure of the foam aluminum sandwich plate increases, and the porosity increases with the increase of the porosity. The elastic modulus and yield strength of the aluminum foam sandwich plate decrease gradually, which further proves that the mechanical properties of the matrix metal directly determine the compressive deformation behavior of the foam aluminum sandwich plate material, and the elastic modulus of the foam aluminum sandwich plate material. The yield strength is related to the corresponding properties of the matrix metal material.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.4

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