Zhu Hu, Cheng Guixi, Jung Dongwon
College of Mechanical and Electrical Engineering, Shenyang Aerospace University, Shenyang 110023, China.
Department of Mechanical Engineering, Jeju National University, Jeju-si 63243, Korea.
Materials (Basel). 2021 Aug 25;14(17):4818. doi: 10.3390/ma14174818.
To solve the problems that exist in the multi-stage forming of the straight wall parts, such as the sheet fracture, uneven thickness distribution, and the stepped feature sinking, a new forming toolpath planning and generation method for the multi-stage incremental forming was proposed based on the stretching angle. In this method, the parallel planes that were used for forming toolpath generation were constructed by using the stretching angle so that the distances between the parallel planes and the forming angles were gradually reduced. This makes the sheet material flow become changed and the thickness thinning is relieved. The software system for the toolpath generation was developed by using C++, VC++, and OpenGL library. In order to verify the feasibility of the proposed method, numerical simulation and forming experiments were carried out for the single stage forming, the traditional multi-stage forming, and multi-stage forming based on the proposed forming toolpath, using 1060 aluminum sheets. The comparative analysis of the thickness distribution, profile curve, strain curve, and sheet material flow shows that the proposed method is feasible, and the profile dimension accuracy is better, the thickness distribution is more uniform, and the sinking and bulging are significantly reduced. The formed sheet part with the stretching angle of 15° has higher dimensional accuracy, smaller bottom subsidence, and larger thickness than that of the stretching angle 5°.
为解决直壁零件多道次成形过程中存在的板材断裂、厚度分布不均以及台阶特征下沉等问题，基于拉伸角提出了一种新的多道次增量成形刀具路径规划与生成方法。该方法利用拉伸角构建用于生成成形刀具路径的平行平面，使平行平面与成形角之间的距离逐渐减小。这使得板材材料流动发生变化，厚度变薄现象得到缓解。利用C++、VC++和OpenGL库开发了刀具路径生成软件系统。为验证所提方法的可行性，采用1060铝板对单道次成形、传统多道次成形以及基于所提成形刀具路径的多道次成形进行了数值模拟和成形实验。对厚度分布、轮廓曲线、应变曲线和板材材料流动的对比分析表明，所提方法可行，轮廓尺寸精度更高，厚度分布更均匀，下沉和鼓包现象明显减少。拉伸角为15°的成形板材零件比拉伸角为5°的具有更高的尺寸精度、更小的底部下沉和更大的厚度。
