|
马上注册,结交更多好友,享用更多功能,让你轻松玩转社区。
您需要 登录 才可以下载或查看,没有账号?我要加入
x
本帖最后由 wdhd 于 2016-5-17 09:33 编辑
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
|
|