Shear

 

Horizontal vs Vertical Shear

shear strength parallel to grain << shear strength across grain

 

Shear Stress

ASD:  f_v = VQ/Ib = 1.5V/A (for rectangles) ≤ F'_v  (CE 110 chapter 9)
LRFD:  V_u ≤ 2F'_vnA/3

bending.xlsx

 

 

Shear Force Reduction

see textbook Example 6.13 and NDS section 3.4.3.1 for possible reduction in V  (conservative to ignore it)

V^* = reduced V

 

Adjusted Design Values

F'_v = F_v(C_D)(C_M)(C_t)(C_L)(C_F or C_V)(C_fu)(C_c)(C_i)(C_r)
F'_vn = F_vn(Φ_v)(λ)(C_M)(C_t)(C_L)(C_F or C_V)(C_fu)(C_c)(C_i)(C_r)

 

Shear vs Bending

shear may control in short, heavily loaded spans

 

Notches

d_n = depth at notch

NDS section 3.4.3.2

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stress concentration factors

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