开孔层合板线弹性仿真模型研究

Investigation on Linear Elastic Finite Element Model of an Open-hole Laminate

复合材料层合板对车身轻量化设计有重要意义。由于避让和连接等需求,复合材料车身结构件多为开孔结构。同时,在整个车身结构分析中,由于计算规模过大,一般采用较大网格尺寸的线弹性复合材料模型进行分析。因此,需在线弹性模型条件下建立有效的复合材料开孔板力学性能分析方法。本文采用常用的线弹性假设,基于单向板实验数据预测开孔板拉伸力学响应,研究网格尺寸对开孔板力学性能预测精度的影响。结果发现,对于孔径为6 mm的准各向同性层合板,网格尺寸为1 mm时,力学性能预测精度最优,当网格尺寸调整为10 mm时,需基于实验数据重新进行单层板力学性能对标。

Composite laminates are valuable for light-weight design of vehicles.Due to the requirement of joint and space avoidance,open-hole laminates are generally employed in engineering.Meanwhile,a linear-elastic model with relatively large mesh size for a composite laminate is generally used,considering the massive computational cost of car body full-scale FEM analysis.Therefore,it is desirable to establish an effective analysis method for open-hole composite laminate,under the condition of linear elastic model.With the linear elastic assumption,this work predicted the mechanical properties of an open-hole laminate under uniaxial tensile load,based on the experimental mechanical properties of the unidirectional composite.The influence of mesh size on the prediction ability of FEM are investigated.It is found that the model with 1 mm mesh size gives the best prediction results for a quasi-isotropic laminate with a 6 mm open-hole.When the mesh size is set as 10 mm,the input data of the unidirectional composite have to be re-calibrated.