拼焊板自由弯曲中的动能与回弹预测精度分析  

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

作　　者：朱元右[1] 

机构地区：[1]南京工程学院机械工程系,江苏南京211100

出　　处：《锻压装备与制造技术》2007年第5期76-79,共4页China Metalforming Equipment & Manufacturing Technology

摘　　要：拼焊板具有焊缝、焊接应力、板厚差等一系列特征,拼焊板回弹模拟计算准确程度受成形过程和回弹模拟的影响,如何解决拼焊板回弹模拟的准确性和收敛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;动力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;应考虑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;此外,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等都对拼焊板回弹产生影响。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 forming process and springback simulation ,so it is important to solve the problems about accuracy and astringency of TWBs＇ springback simulation.It is turned out that their advantages 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 bringing effect of inertia during increasing the subjunctive kinematical velocity of the tools. When the parameter of bigger profile radius and small kinetic energy is adopted,the accuracy of springback＇s simulation can be increased.Both the welding stress field and the especial 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 etc, affect TWBs＇ springback.

关 键 词：机械制造 弯曲回弹 拼焊板 数值模拟 

分 类 号：TG76[金属学及工艺—刀具与模具]