NASTRAN动力学分析的阻尼类型以及瑞利阻尼的调用

superuirui

　　Damping types in NASTRAN:
　　1. Viscous -- damping force is proportational to velocity(i.e. frequency dependent)
　　2. Structural -- damping force is proportational to displacement
　　3. Rayleigh damping -- damping force is proportation to stiffness and/or mass
　　Rayleigh damping:
　　Not supported in Patran, requires Direct Text Input
　　Proportational to either the mass or stiffness matrix
　　Also known as proportational damping
　　Proportational to mass matrix (param, alpha1, x)
　　Proportational to stiffness matrix (param, alpha2, y)
　　Available in transient and frequency response analysis
　　Scale factors applied to d-set (direct) and h-set (modal)
　　Added to the viscous damping matrix as follows:
　　[B'] = [B] + alpha1*[M] + alpha2*[K]
　　ALPHA1 and ALPHA2 are complex parameters

mxlzhenzhu

版主，请问，patran中是如何对结构表面的二维网格进行编号的？

我用HM定义的二维网格编号，到了patran中就乱套了，我想nastran肯定也无法识别，f06文件中也有明显warning，这个问题很困扰我。

zhangcanfei

瑞利阻尼模型需要 怎么输入到计算文件当中，求给个格式啊 、

eastar

能再详细点吗