Mechanical properties and cold and warm forming characteristics of sandwich sheets with a three-dimensional CFRTP core
Mechanical properties and cold and warm forming characteristics of sandwich sheets with a three-dimensional CFRTP core
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DOI：
10.1016/j.compstruct.2021.114048
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发表时间：
2021-08
影响因子：
6.3
通讯作者：
Jingwei Zhang;T. Taylor;J. Yanagimoto
中科院分区：
文献类型：
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作者：
Jingwei Zhang;T. Taylor;J. Yanagimoto
含三维芯的夹芯板由于制造效率低、成形性差，限制了其应用。金属基夹层板，其中薄金属面板用于夹层和粘合三维芯，通过冲压最初平坦的碳纤维增强热塑性塑料（CFRTP）板，能够提供高比刚度，适合大规模生产。针对这种夹层板的二次成形，研究了不同纤维长度和体积分数的不同面板和三维CFRTP芯组成的夹层板的冷热成形特性。通过理论公式将数值预测的纯弯曲刚度和面外剪切模量转换为数值三点弯曲刚度，并与实验值进行比较，明确了不同夹层板的力学性能。采用碳纤维体积分数为40%的超薄剪切碳纤维带增强热塑性塑料（UTCTT）热冲压技术，成功制备了三维芯材。拉伸弯曲表明，可以通过优化材料组合和成形温度来提高夹芯板的成形性。由金属面板和短碳纤维增强热塑性塑料（SCFRTP）芯组成的夹层板可以很容易地冷成型，而具有UTCTT芯的夹层板可以很容易地热成型。
The application of sandwich sheets containing a three-dimensional core is limited due to low manufacturing efficiency and poor formability. Metal-based sandwich sheets, where thin metallic face sheets are used to sandwich and bond with a three-dimensional core fabricated by stamping an initially flat carbon fibre reinforced thermoplastic (CFRTP) sheet, are able to provide high specific stiffness with suitability for mass production. Aiming at secondary forming such sandwich sheets into three-dimensional shapes, cold and warm forming characteristics of sandwich sheets composed of various face sheets and a three-dimensional CFRTP core with different fibre lengths and volume fractions were investigated. The numerically predicted pure bending rigidity and out-of-plane shear modulus were converted into numerical three-point bending stiffness through theoretical formulas and compared with experimental values to clarify the mechanical properties of different sandwich sheets. A three-dimensional core was successfully fabricated by warm stamping ultrathin chopped carbon fibre tape reinforced thermoplastic (UTCTT) with carbon fibre volume fraction of 40%. Draw-bending demonstrates that formability of sandwich sheets can be improved by optimising material combinations and forming temperatures. Sandwich sheets composed of metallic face sheets and a short carbon fibre reinforced thermoplastic (SCFRTP) core can be easily cold formed, while those with a UTCTT core can be easily warm formed.