拼焊板弯曲成形中的回弹精确预测及关键问题分析  

Several Problems of Numerical Simulation in Bending Springback of Tailor-welded Blanks

作　　者：马伟民[1] 朱元右[2] 王力[1] 李路娜[1] 

机构地区：[1]江苏大学工业中心,江苏镇江212013 [2]南京工程学院,南京210013

出　　处：《煤矿机械》2008年第5期91-93,共3页Coal Mine Machinery

摘　　要：拼焊板具有焊缝、焊接应力、板厚差等一系列特征,如何解决拼焊板回弹模拟的准确性是拼焊板回弹数值模拟的重要问题。分析认为,联合动态显式算法求解和静态隐式算法充分发挥了二者的优点,动态显式解法分析时每步时间增量必须小于由系统最高固有频率所确定的临界时间步长;提高工具虚拟运动速度时应避免引起惯性效应;模具凹模圆角半径参数较大时,其动能相对要小,可提高回弹模拟精度;网络划分的质量,单元类型,模具的几何轮廓形状的描述,板材网格尺寸及处理技术等都对拼焊板回弹产生影响。当单元尺寸为模具圆角半径的1/2时,回弹结果与实验结果最为接近。另外,应进一步研究焊接应力场和拼焊板特有的力学行为和规律,提高对成形应力与残余应力预测结果的精度。Tailor- Welded Blanks （TWBs） has the following characteristics, welded - line movement, welding stress, different thickness. The accuracy of simulation calculation about TWBs＇ springback is affected by form ing process and springback simulation, so it is important to resolve the problems about accuracy and astringen- cy of TWBs＇ springback simulation. It is turned out that their excellence can be made full use of by the combination of dynamic explicit algorithm and static implicit algorithm during solution procedure. The temporal increment per step during dynamic explicit analysis must be smaller than the critical time step confirmed by systemic maximal natural frequency. It should avoid to bring effect of inertia during increasing the subjunctive ki- nematical velocity of the tools. When the paraneter of bigger profile radius and small kinetic energy is adopted, the accuracy of springback simulation can be increased. Both the welding stress field and the es, pecial behavior of mechanics must be considered to improve predicted accuracy of the remnant stress in TWBs forming. Moreover, the quality of mesh division, the mode of element, the description of geometric profile of the mould, the mesh and so on all affect TWBs＇ springback.

关 键 词：拼焊板 弯曲回弹 数值模拟 

分 类 号：TG457[金属学及工艺—焊接]