Numerical calculation of stretch bending of narrow strip and analysis on spring back
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摘要: 在考虑加载历史的情况下,为采用数值方法研究窄板拉弯成形,将变形区划分成若干个单元,按塑性变形体积不变条件,确定单元应变.利用增量理论,由差分方程算出应力分布,并分析了加载历史对其影响.依据卸载变形的分析计算,推导出回弹后中性层弯曲半径及弯曲角变化量的计算公式.计算结果表明,先弯曲再拉伸时应力分布规律更利于减小回弹.Abstract: To analyse stretch bending of narrow strip by numerical calculation, taking the loading history into account, the deformed zone was divided intomany elements to determine their strain by the condition that constant volume remains in deformation. Increment strain theory was applied to calculating the stress distribution from difference equation and the effect of loading history on them was discussed. The formulae for calculating the bend radius of neutral plane and the decrement of bend angle after springback were derived by considering the deformation after unloading. The simulative results show that stress distribution under stretching with superimposed bending is more advantageous to the reduction of spring back.
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Key words:
- bending /
- numerical calculation /
- residual stress /
- spring back
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