板材弯曲回弹的多参数随机特性研究

Study on Multi-Parameter Probability of Sheet Bending Spring-Back

研究板材材料及几何参数对板材卸载后弯曲半径和回弹角的影响。建立了基于双线性硬化材料模型的板材弯曲的理论力学模型,并建立了包含屈服应力、刚性模量、弯曲半径、弯曲角的随机性的板材弯曲回弹的概率分析的理论模型,此外,基于蒙特卡罗扩展法建立了其显式—隐式的概率有限元模型,得到了弹性模量、泊松比、弯曲角度等参数对板材卸载后弯曲半径和回弹角的影响规律,回弹角对弹性模量最敏感,卸载后板料的弯曲半径对原弯曲半径最敏感,应用该方法为板材弯曲回弹分析提供了方法和依据。

The influence of sheet material parameters and geometric parameters to the bending radius and spring-back angle after unloading was studied. Bending mechanical model of sheet was established when the material model was the bilinear hardening model Moreover, considering the randomness of yield stress, rigidity modulus, bending radius, and bending angle, the probability analysis of sheet bending theoretical model was established. Furthermore, based on extension of the Monte Carlo method, probabilistic explicit-to-implicit finite element model was established, the influence of elastic modulus, Poisson＇s ratio, bending angles and other parameters to the bending radius and spring-back angle of the sheet after unloading was obtained. Research results show that the spring-back angle is the most sensitive to its plastic modulus and bending radius after unloading the most sensitive to its bending radius. The method and basis are supported for the bending spring-back analysis of the sheet.