板料自由弯曲成形及回弹理论解析kgxsn.docx

第 16 卷 第 4 期2009 年 8 月塑性工程学报J OU RNAL OF PL ASTICIT Y EN GIN EERIN GVol116 No14Aug1 2009doi :101 3969/ j1 issn1 1007220121 20091 041 001板料自由弯曲成形及回弹理论解析 3(燕山大学 机械工程学院 , 秦皇岛 066004) 李 建 赵 军 展培培 孙红磊 马 瑞摘 要 : 对宽板自由弯曲成形及弹复过程进行理论分析 , 将弯曲过程分为板料未包覆凸模和已包覆凸模两个成形 阶段 , 在每个成形阶段将弯曲板料分为弹性和弹塑性变形区 。基于单向应力和小变形假设 , 分别建立了两个成形阶 段的回弹计算模型 , 导出了任一成形阶段中性层上任一质点卸载前后的转角和弯曲半径数学表达式 。基于 VC + + 软件平台 , 对回弹计算模型进行编程计算 , 并进行了实验验证 , 计算结果与实验结果吻合较好 , 最大误差为 0158°。关键词 : 回弹 ; 自由弯曲 ; 理论解析 ; VC + +中图分类号 : T G386 文献标识码 : A 文章编号 : 100722012 (2009) 0420001206Theoretic analysis of forming and springback for sheet metal air bendingL I Jian ZHAO J un ZHAN Pei2pei SUN Hong2lei MA Rui(College of Mechanical Engineering , Yanshan University , Qinhuangdao 066004 China)Abstract : With theoretic analysis on the forming and springback processes for sheet metal forming , the sheet metal air bending process can be divided into two stages including one stage of not wrapping the sheet about the punch surface and the other stage of having wrapped up the punch surface. In each forming stage , the deformed region of the sheet metal is considered to be composed of elastic region and elastic2plastic region. Using the assumptions of uniaxial st ress and the little deforming theory , the analytical model of springback prediction is constructed. The equations for the rotation angle and radius of each point in neutral surface forany bending process are derived. The code is developed to calculate the springback amount based on VC + + program. The air bending experiment is conducted to verify the validation of the theoretic model of springback prediction. The comparison showsthat the theoretical results of springback prediction fit well with experimental data and the maximum error is 0158°.Key words : springback ; air bending ; theoretic analysis ; VC + +引 言板材自由弯曲成形是一种柔性加工工艺 , 使用 较少的模具组合能够成形多种规格的弯曲件 , 因而 在航空 、汽车和家电等制造领域得到了广泛地应用