Table 1 Resistant components of various truss models
Model | Resistant components | Responses | |||||
|---|---|---|---|---|---|---|---|
V c | V s (=V t ) | θ | f v stirrup stress | ΔT tension shift | |||
Vuc (= va) | Vci | Vd | |||||
Classical truss model | X | X | X | ○ | 45° | \( \frac{1}{{\rho_{v} b_{w} z_{o} }}(V) \) | 1/2(V) |
Standard truss model type (a) | X | X | X | ○ | Variable | \( \frac{\tan \theta }{{\rho_{v} b_{w} z_{o} }}(V) \) | 1/2(V) cotθ |
Modified truss model | |||||||
ACI | ○ Lump sum V c (fixed) | ○ | 45° | \( \frac{1}{{\rho_{v} b_{w} z_{o} }}(V - V_{c} ) \) | 1/2(V − V c ) | ||
EC-2 | ○ Lump sum V c (fixed) | ○ | Variable | \( \frac{\tan \theta }{{\rho_{v} b_{w} z_{o} }}(V - V_{c} ) \) | 1/2(V − V c ) cotθ | ||
AASHTO LRFD | X | ○ (vari able) | X | ○ | Variable | \( \frac{\tan \theta }{{\rho_{v} b_{w} z_{o} }}(V - V_{ci} ) \) | 1/2(V − V ci ) cotθ |
Complex truss model | |||||||
Type (b) | ○ | X or ○ | X | ○ | Irregular variable | Undefined | |
Type (c) | ○ | X or ○ | X | ○ | Irregular variable | Undefined | |
Type (d) | ○ | X or ○ | X | ○ | Irregular variable | Undefined | |