The paper starts with a brief overview to the necessity of sheet metal forming simulation and the complexity of automobile panel forming, then leads to finite element analysis (FEA) which is a powerful simulation too...The paper starts with a brief overview to the necessity of sheet metal forming simulation and the complexity of automobile panel forming, then leads to finite element analysis (FEA) which is a powerful simulation tool for analyzing complex three-dimensional sheet metal forming problems. The theory and features of the dynamic explicit finite element methods are introduced and the available various commercial finite element method codes used for sheet metal forming simulation in the world are discussed,and the civil and international status quo of automobile panel simulation as well. The front door outer panel of one certain new automobile is regarded as one example that the dynamic explicit FEM code Dynaform is used for the simulation of the front door outer panel forming process. Process defects such as ruptures are predicted. The improving methods can be given according to the simulation results. Foreground of sheet metal forming simulation is outlined.展开更多
为揭示钢筋混凝土桥面板在爆炸荷载作用下的动态力学响应及损伤机理,在RHT动态本构和显式动态数值分析模型合理性验证的基础上,研究了不同TNT当量、板厚度以及钢筋直径对桥面板受爆力学性能的影响。研究结果表明:基于RHT动态本构的显式...为揭示钢筋混凝土桥面板在爆炸荷载作用下的动态力学响应及损伤机理,在RHT动态本构和显式动态数值分析模型合理性验证的基础上,研究了不同TNT当量、板厚度以及钢筋直径对桥面板受爆力学性能的影响。研究结果表明:基于RHT动态本构的显式动态数值分析结果与构件抗爆试验表征一致,能够反映结构在爆炸荷载下的动态力学响应和损伤机理。TNT炸药当量是影响钢筋混凝土桥面板破坏形态的主要因素,在小当量条件下(2 kg TNT),结构发生轻微损伤,板在2个方向力学特征与单向桥面板的受力规律一致,同时应力及变形时程曲线呈自由振动特征,振动周期为3.68 ms。TNT当量逐渐增加时(5,10 kg TNT),桥面板在数毫秒内发生损伤,板在2个方向最大正应力逐渐趋于一致,损伤特征主要表现为局部冲剪破坏,刚度下降后导致其振动频率降低,振动周期分别增加至4.38,8.64 ms。TNT当量进一步增加时(20 kg TNT),结构直接发生大范围冲剪破坏,并迅速失效。板厚增加能够显著提升结构的抗爆性能,增加13%及30%时,损伤区域范围分别降低57.5%及82.5%。钢筋直径增加时,在一定范围内提升了结构刚度,但对于结构的整体抗爆性能改善并不显著。展开更多
文摘The paper starts with a brief overview to the necessity of sheet metal forming simulation and the complexity of automobile panel forming, then leads to finite element analysis (FEA) which is a powerful simulation tool for analyzing complex three-dimensional sheet metal forming problems. The theory and features of the dynamic explicit finite element methods are introduced and the available various commercial finite element method codes used for sheet metal forming simulation in the world are discussed,and the civil and international status quo of automobile panel simulation as well. The front door outer panel of one certain new automobile is regarded as one example that the dynamic explicit FEM code Dynaform is used for the simulation of the front door outer panel forming process. Process defects such as ruptures are predicted. The improving methods can be given according to the simulation results. Foreground of sheet metal forming simulation is outlined.
文摘为揭示钢筋混凝土桥面板在爆炸荷载作用下的动态力学响应及损伤机理,在RHT动态本构和显式动态数值分析模型合理性验证的基础上,研究了不同TNT当量、板厚度以及钢筋直径对桥面板受爆力学性能的影响。研究结果表明:基于RHT动态本构的显式动态数值分析结果与构件抗爆试验表征一致,能够反映结构在爆炸荷载下的动态力学响应和损伤机理。TNT炸药当量是影响钢筋混凝土桥面板破坏形态的主要因素,在小当量条件下(2 kg TNT),结构发生轻微损伤,板在2个方向力学特征与单向桥面板的受力规律一致,同时应力及变形时程曲线呈自由振动特征,振动周期为3.68 ms。TNT当量逐渐增加时(5,10 kg TNT),桥面板在数毫秒内发生损伤,板在2个方向最大正应力逐渐趋于一致,损伤特征主要表现为局部冲剪破坏,刚度下降后导致其振动频率降低,振动周期分别增加至4.38,8.64 ms。TNT当量进一步增加时(20 kg TNT),结构直接发生大范围冲剪破坏,并迅速失效。板厚增加能够显著提升结构的抗爆性能,增加13%及30%时,损伤区域范围分别降低57.5%及82.5%。钢筋直径增加时,在一定范围内提升了结构刚度,但对于结构的整体抗爆性能改善并不显著。
