Y型蜂窝等效模型及蜂窝夹芯结构车体的仿真分析

Y-shaped honeycomb equivalent model and simulation analysis of carbody structures of honeycomb sandwich composites

复合材料夹芯结构在轨道车辆车体轻量化中应用广泛,但在大型夹芯结构车体仿真计算时,存在结构层次复杂且分析经验较为缺乏等问题。本文提出考虑蜂窝双壁影响的Y型蜂窝等效模型,然后基于Y型蜂窝等效构建碳纤维铝蜂窝夹芯板和格栅增强碳纤维铝蜂窝夹芯板仿真分析模型,并将其分别与三点弯曲试验进行验证。根据传统列车车体的蒙皮骨架形式,构建碳纤维铝蜂窝车体和格栅增强碳纤维铝蜂窝车体,并运用BSEN12663:2010标准和《复合材料设计手册》中的设计标准分析其刚度、强度、应变等力学性能。研究结果表明:碳纤维铝蜂窝夹芯板和格栅增强碳纤维铝蜂窝夹芯板三点弯曲仿真结果与试验值误差分别为2.8%和0.1%,验证了Y型蜂窝等效模型具有较高的精度;碳纤维铝蜂窝车体的比刚度最低提升了49.4%,强度最高提升了64.5%;格栅增强碳纤维铝蜂窝车体的比刚度最低提升了67.6%,强度最高提升了66.2%。对于2种蜂窝夹芯结构车体的蒙皮来说,格栅增强碳纤维铝蜂窝车体应变最低下降了36.9%,失效因子最低下降了61.1%,相比碳纤维铝蜂窝车体有较充足的安全余量;相比原不锈钢车体,2种蜂窝夹芯结构车体具有较好的减重效果,碳纤维铝蜂窝车体减重33.4%,格栅增强碳纤维铝蜂窝车体减重13.1%。基于Y型蜂窝等效模型的碳纤维夹芯结构仿真分析,为先进复合材料轨道车辆车体结构轻量化设计提供了参考。

Composite sandwich structures are widely used in the lightweighting of rail vehicle bodies.However,the structural hierarchy of large sandwich structure bodies is complex and its simulation lacks analytical experience.In this paper,a Y-shaped honeycomb equivalent model was proposed to consider the effect of double-back wall thickness.Then the simulation models of carbon-fiber/aluminum-honeycomb sandwich panels and carbon-fiber/grid reinforced aluminum-honeycomb sandwich panels were constructed based on the Y-shaped honeycomb equivalent.The results were verified with three-point bending experiments.Based on the skeleton layout of the conventional vehicle body,the carbon-fiber/aluminum-honeycomb vehicle body and the carbon-fiber/grid reinforced aluminum-honeycomb vehicle body were established.Their mechanical properties such as stiffness,strength,and strain were analyzed based on the BS EN 12663:2010 standard and the design criteria in the Composites Design Manual.The research results as shown as follows.The three-point bending simulation results of carbon-fiber/aluminum-honeycomb sandwich panels and carbon-fiber/grid reinforced aluminum-honeycomb sandwich panels have an error of 2.8% and 0.1% from the experimental values,which verifies that the Y-shaped honeycomb equivalent model has a high accuracy.The carbon-fiber/aluminum-honeycomb vehicle body exhibits a minimum increase of 49.4% in specific stiffness and a maximum increase of 64.5% in strength.The carbon-fiber/grid reinforced aluminum-honeycomb vehicle body shows a minimum increase of 67.6% in specific stiffness and a maximum increase of 66.2% in strength.For the skins of the two honeycomb sandwich structure bodies,the carbon-fiber/grid reinforced aluminum-honeycomb vehicle body has a minimum strain reduction of 36.9% and a minimum failure factor reduction of 61.1%,which can provide a more adequate safety margin compared to the carbon-fiber/aluminum-honeycomb vehicle body.Compared with the original stainless steel body,the carbon-fiber/aluminum-honeycomb vehicle body exhibits a weight reduction of 33.4%,while the carbon-fiber/grid reinforced aluminum-honeycomb vehicle body shows a weight reduction of 13.1%.Both honeycomb sandwich structure bodies demonstrate significant improvements in weight reduction.Simulation of carbon fiber sandwich structure based on Y-shaped honeycomb equivalent model can provide a reference for lightweight design of advanced composite rail vehicle body structure.