一种整体壁板填料辅助滚弯成形过程中填料作用机理

Operating effect of filler on filling roll bending of integral panel

研究一种2A12铝合金整体壁板的聚丙烯填料辅助滚弯成形工艺,结合力学分析、数值模拟和实验验证,揭示填料的作用机理。结果表明,整体壁板筋条与蒙皮处的中性层位置差导致其成形后母线直线度不达标,填料可以降低这种中性层位置差。当填料与筋条有一定宽度间隙(1~3 mm)时,可以避免填料卷曲和筋条失稳。而填料和筋条的高度间隙决定填料可被压缩程度,当填料在压缩后仍高于筋条(1 mm)时,可以达到最佳的压力传递效果。填料的弹性模量在一定范围内时(450~1300 MPa),对整体壁板的成形精度影响不大。但填料弹性模量较低时(50 MPa),填料传递的压力不足;填料弹性模量较高时(20 GPa),整体壁板弯曲变形受限。实验后壁板母线直线度的测量结果验证了填料的作用机理。

A filling roll bending process of a 2A12 aluminum alloy integral panel with polypropylene as filler was studied.The operating effect of filler was revealed,based on analytical,numerical,and experimental methods.The results show that the position difference of the neutral layer between the ribs and the web of the integral panel leads to the error of generatrix straightness,and the filler can reduce this difference.A certain range of the width gap(1−3 mm)between filler and rib can avoid the instability of the rib and the curl of the filler.The height gap between filler and rib determines the compression degree of filler.The best pressure transmission effect can be achieved as the filler is still higher than the rib(1 mm)after compression.The elastic modulus of filler slightly affects the forming accuracy of the integral panel within a certain range(450−1300 MPa).Still,the filler transfers insufficient pressure under lower elastic modulus(50 MPa)and limits the deformation of the integral panel under higher elastic modulus(20 GPa).Experimentally measured generatrix straightness verified the operating effect of filler.