金属层合板板形翘曲变形行为

Warpage deformation behavior of metal laminates

  • 摘要: 采用经典弹性力学方法建立了金属层合板翘曲解析计算力学模型,获得了厚度方向不均匀延伸与板形翘曲之间的定量关系;并分别建立了在线和离线两种状态下金属层合板翘曲变形的有限元数值模拟模型,对解析计算力学模型进行了验证;在此基础上,揭示了金属层合板产生板形翘曲缺陷的力学根源以及各因素对金属层合板板形翘曲缺陷演变的影响规律,同时对比分析了双层和三层结构层合板与均质板的翘曲变形差异以及铜/碳钢层合板与不锈钢/碳钢层合板二者之间的翘曲变形差异。研究表明,金属层合板翘曲高度与延伸差、厚度比呈正比关系,与厚度呈反比关系,且基层与覆层的切变模量相差越大,厚度比对金属层合板翘曲变形的影响越大。基于数值模型,模拟研究了层合板在理想均匀分布的初始温度下,历经去应力退火过程时,其板形翘曲的变形行为及规律,并与均质板进行比较。最后,在工业生产现场取样已翘曲层合板,通过测量其弯曲变形量进而反求其初始延伸差,验证了解析计算力学模型的准确性。

     

    Abstract: The layered characteristics of the material in the thickness direction of the metal laminate make it more prone to uneven plastic extension during the thinning, rolling, flattening, and straightening process, resulting in plate-shaped warpage defects and cause the plate-shaped warpage of the metal laminate. The behavior is significantly different from that of a homogeneous metal plate. In this paper, the classical elastic mechanics method was used to establish an analytical computational mechanical model for the warpage of the metal laminate, and the quantitative relationship between the uneven extension in the thickness direction and the warpage of the plate shape was obtained; the online and offline states of the metal laminate were established, respectively. The finite element numerical simulation model of warpage deformation validated the analytical computational mechanics model; based on this, it revealed the mechanical roots of the shape warping defects of metal laminates and the effect of various factors on the shape warpage defects of metal laminates. The influence law of evolution and the difference in warpage deformation between double-layer and three-layer structure laminates and homogeneous plates, as well as the difference in warpage deformation between copper/carbon steel laminates and stainless steel/carbon steel laminates, were compared. Studies have shown that the warpage height of the metal laminate is proportional to the elongation difference and thickness ratio, and it is inversely proportional to the thickness. The greater the difference between the shear modulus of the base layer and the cladding layer is, the larger the effect of the thickness ratio on the warpage deformation of the metal laminate will be. Based on the numerical model, simulation studies were conducted on the deformation behavior and regularity of the plate shape warping of the laminated plate under the ideal uniform distribution of the initial temperature and the stress relief annealing process, and it was compared with that of the homogeneous plate. Finally, a sample of the warped laminate was taken at an industrial production site, and the initial extension difference was reversed by measuring its bending deformation. The result verifies the accuracy of the analytical computational mechanical model.

     

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