Zhang Ya, Chen Qingmin, Wang Mingwei, Zhang Xi, Cai Zhongyi
College of Materials Science and Engineering, Jilin University, Changchun 130025, China.
Roll Forging Research Institute, Jilin University, Changchun 130025, China.
Materials (Basel). 2021 Aug 30;14(17):4955. doi: 10.3390/ma14174955.
This paper studies the plastic forming of sandwich panels and proposes a universal elastoplastic equivalent method suitable for sandwich panels. To verify the generality of the equivalent method, according to the different core structures, the cores of bi-directional trapezoidal sandwich (BTS) panels and aluminum foam sandwich (AFS) panels are equated to orthotropic and isotropic (special orthotropic) single-layer panels respectively. Through the finite element (FE) numerical simulation of the mesoscopic model of the sandwich panel, the elastoplastic constitutive relationship of the equivalent core model is established, and then the macroscopic equivalent model of the sandwich panel is established. The FE numerical simulation of plastic forming was carried out for the mesoscopic model and equivalent model of BTS panel and AFS panel, and plastic forming experiments were conducted for the sandwich panel through a multi-point forming (MPF) test machine. The results show that the relative errors of the section average stress at the same position of the equivalent model and the mesoscopic model of sandwich panels are all within 4%; compared with the experimental results, the equivalent model of the sandwich panel has high forming accuracy and small shape error, which verifies the high accuracy and generality of the equivalent method. Moreover, using the sandwich panel equivalent model effectively reduces the calculation time of the numerical simulation.
本文研究了夹芯板的塑性成形，并提出了一种适用于夹芯板的通用弹塑性等效方法。为验证等效方法的通用性，根据不同的芯材结构，将双向梯形夹芯（BTS）板和泡沫铝夹芯（AFS）板的芯材分别等效为正交各向异性和各向同性（特殊正交各向异性）单层板。通过夹芯板细观模型的有限元（FE）数值模拟，建立了等效芯材模型的弹塑性本构关系，进而建立了夹芯板的宏观等效模型。对BTS板和AFS板的细观模型及等效模型进行了塑性成形的FE数值模拟，并通过多点成形（MPF）试验机对夹芯板进行了塑性成形实验。结果表明，夹芯板等效模型与细观模型相同位置处的截面平均应力相对误差均在4%以内；与实验结果相比，夹芯板等效模型具有较高的成形精度和较小的形状误差，验证了等效方法的高精度和通用性。此外，使用夹芯板等效模型有效减少了数值模拟的计算时间。
