Effect of continuous strain path changes on forming limit strains of DP600

The strain path may change in actual sheet metal‐forming processes, so the determination of formability of sheet metal should consider the nonlinear strain path. For identifying the forming limit (FL) strains under nonlinear strain path, a conventional two‐step procedure with unloading is classically used to produce the strain path change, which results in no continuous measure of strain. The in‐plane biaxial tensile test with a cruciform specimen is an interesting alternative to overcome the drawbacks of conventional method. The strain path change can be made without unloading during a single test. In this work, the experimental FL strains of DP600 sheets under two types of nonlinear strain path are investigated and then compared with those under linear strain paths. The Oyane ductile fracture criterion is used in the finite element simulation to predict the experimental results.     

基于FLCN方法的足球机器人动作控制

考虑到足球机器人比赛中射门动作的重要性,为了使足球机器人的动作具有准确性,提出了一种基于FLCN（Fuzzy Limit-Cycle Navigation,即模糊极限环导航）方法的动作控制。通过对极限环形状的改进,使其具有椭圆特性;并针对该情况设计了相应的模糊规则,应用模糊算法确定椭圆中心点的位置来导航机器人,完成截球和射门的动作。在仿真试验与集控式足球机器人实战中进行了验证,结果证明了该方法的有效性。