Variables Dimensionless variables Coordinates
𝑥
,
𝑋
𝑜
,
𝑌
𝑜
𝑥
𝑥
=
𝐿
𝑇
,
𝑋
𝑜
=
𝑋
𝑜
𝐿
𝑇
,
𝑌
𝑜
=
𝑌
𝑜
/
𝐿
𝑇
,Time
𝑡
𝑡
𝜏
=
𝐿
𝑇
𝐸
𝜌
Length of beam element
𝐿
𝐿
=
𝐿
/
𝐿
𝑇
Area moment of inertia
𝐼
𝐼
𝐼
=
𝐴
𝐿
2
𝑇
Radius of hub
𝑅
𝑅
=
𝑅
/
𝐿
𝑇
Displacements
𝑢
,
𝑣
𝑢
=
𝑢
/
𝐿
𝑇
,
𝑣
=
𝑣
/
𝐿
𝑇
spatial derivatives of displacement
𝑢
,
𝑢
,
𝑣
,
𝑣
𝑢
=
𝜕
𝑢
𝜕
𝑥
=
𝑢
,
𝑢
=
𝜕
2
𝑢
𝜕
𝑥
2
=
𝐿
𝑇
𝑢
,
𝑣
=
𝜕
𝑣
𝜕
𝑥
=
𝑣
,
𝑣
=
𝜕
2
𝑣
𝜕
𝑥
2
=
𝐿
𝑇
𝑣
Time derivatives of displacement
̇
𝑢
,
̈
𝑢
,
̇
𝑣
,
̈
𝑣
̇
𝜕
𝑢
=
𝑢
𝜕
𝜏
=
̇
𝑢
𝜌
𝐸
,
̈
𝜕
𝑢
=
2
𝑢
𝜕
𝜏
2
=
𝐿
𝑇
𝜌
𝐸
̇
̈
𝑢
,
𝜕
𝑣
=
𝑣
=
̇
𝑣
𝜕
𝜏
𝜌
𝐸
,
̈
𝜕
𝑣
=
2
𝑣
𝜕
𝜏
2
=
𝐿
𝑇
𝜌
𝐸
̈
𝑣
Force and moment
𝑓
𝑖
𝑗
,
𝑚
𝑗
𝑓
𝑖
𝑗
=
𝑓
𝑖
𝑗
𝐸
𝐴
,
(
𝑖
=
1
,
2
;
𝑗
=
1
,
2
)
Angular velocity
Ω
𝑘
=
Ω
𝐿
𝑇
√
𝜌
/
𝐸
Natural frequency
𝜔
𝐾
=
𝜔
𝐿
𝑇
√
𝜌
/
𝐸